Sample records for determination silica polymer

  1. Rapid synthesis of polymer-silica hybrid nanofibers by biomimetic mineralization

    E-Print Network [OSTI]

    Mather, Patrick T.

    Rapid synthesis of polymer-silica hybrid nanofibers by biomimetic mineralization Pritesh A. Patel. Such a simple route to rapid formation of organic-inorganic hybrid nanofibers could have applications ranging from catalysis to tissue engineering, and nanocomposites in general. Ó 2009 Elsevier Ltd. All rights

  2. Self-Assembled Silica Nano-Composite Polymer Electrolytes: Synthesis, Rheology & Electrochemistry

    SciTech Connect (OSTI)

    Khan, Saad A.: Fedkiw Peter S.; Baker, Gregory L.

    2007-01-24T23:59:59.000Z

    The ultimate objectives of this research are to understand the principles underpinning nano-composite polymer electrolytes (CPEs) and facilitate development of novel CPEs that are low-cost, have high conductivities, large Li+ transference numbers, improved electrolyte-electrode interfacial stability, yield long cycle life, exhibit mechanical stability and are easily processable. Our approach is to use nanoparticulate silica fillers to formulate novel composite electrolytes consisting of surface-modified fumed silica nano-particles in polyethylene oxides (PEO) in the presence of lithium salts. We intend to design single-ion conducting silica nanoparticles which provide CPEs with high Li+ transference numbers. We also will develop low-Mw (molecular weight), high-Mw and crosslinked PEO electrolytes with tunable properties in terms of conductivity, transference number, interfacial stability, processability and mechanical strength

  3. Particle Restabilization in Silica/PEG/Ethanol Suspensions: How Strongly do Polymers Need To Adsorb To Stabilize Against Aggregation?

    SciTech Connect (OSTI)

    Kim, So Youn; Zukoski, Charles F. (UIUC)

    2014-09-24T23:59:59.000Z

    We study the effects of increasing the concentration of a low molecular weight polyethylene glycol on the stability of 44 nm diameter silica nanoparticles suspended in ethanol. Polymer concentration, c{sub p}, is increased from zero to that characterizing the polymer melt. Particle stability is accessed through measurement of the particle second-virial coefficient, B{sub -2}, performed by light scattering and ultrasmall angle X-ray scattering (USAXS). The results show that at low polymer concentration, c{sub p} < 3 wt %, B{sub -2} values are positive, indicating repulsive interactions between particles. B{sub -2} decreases at intermediate concentrations (3 wt % < c{sub p} < 50 wt %), and particles aggregates are formed. At high concentrations (50 wt % < c{sub p}) B{sub -2} increases and stabilizes at a value expected for hard spheres with a diameter near 44 nm, indicating the particles are thermodynamically stable. At intermediate polymer concentrations, rates of aggregation are determined by measuring time-dependent changes in the suspension turbidity, revealing that aggregation is slowed by the necessity of the particles diffusing over a repulsive barrier in the pair potential. The magnitude of the barrier passes through a minimum at c{sub p} {approx} 12 wt % where it has a value of {approx}12kT. These results are understood in terms of a reduction of electrostatic repulsion and van der Waals attractions with increasing c{sub p}. Depletion attractions are found to play a minor role in particle stability. A model is presented suggesting displacement of weakly adsorbed polymer leads to slow aggregation at intermediate concentration, and we conclude that a general model of depletion restabilization may involve increased strength of polymer adsorption with increasing polymer concentration.

  4. Luminescent organosilicon polymers and sol-gel synthesis of nano-structured silica

    E-Print Network [OSTI]

    Martinez, H. Paul

    2011-01-01T23:59:59.000Z

    Photoluminescent   Polymers   Containing   Metalloles.  Metallole-­? Containing  Polymers.   Journal  of  Forensic  S.   J. ;   Trogler,   W.   C. ,   Polymer   sensors   for  

  5. Luminescent organosilicon polymers and sol-gel synthesis of nano-structured silica

    E-Print Network [OSTI]

    Martinez, H. Paul

    2011-01-01T23:59:59.000Z

    filled   hollow   silica   nano-­?   and   microshells  nano-­? extracting  sensor.   Conclusions   The   adsorptive   properties   of   hollow  

  6. POLYMER END-GROUP ANALYSIS: THE DETERMINATION OF AVERAGE MOLECULAR WEIGHT

    E-Print Network [OSTI]

    Weston, Ken

    POLYMER END-GROUP ANALYSIS: THE DETERMINATION OF AVERAGE MOLECULAR WEIGHT Background reading. 11. Skoog, West, Holler and Crouch, 7th ed., Chap. 14. Introduction Polymers Polymers are a special in this experiment, or may be of different types. Polymers are very important in biological systems. For example

  7. Electrospinning of silica nanofibers: characterization and application to biosensing 

    E-Print Network [OSTI]

    Tsou, Pei-Hsiang

    2009-06-02T23:59:59.000Z

    and experimental time were studied. Materials used in the process are Polyvinylpyrrolidone (PVP), butanol and spin-on-glass coating solution, which act as polymer carrier, solvent, and silica-precursor, respectively. Polymer/silica precursor composite fibers were...

  8. Electrospinning of silica nanofibers: characterization and application to biosensing

    E-Print Network [OSTI]

    Tsou, Pei-Hsiang

    2009-06-02T23:59:59.000Z

    and experimental time were studied. Materials used in the process are Polyvinylpyrrolidone (PVP), butanol and spin-on-glass coating solution, which act as polymer carrier, solvent, and silica-precursor, respectively. Polymer/silica precursor composite fibers were...

  9. Polymer ejection from bacteriophages is fully determined by confinement energy

    E-Print Network [OSTI]

    Piili, J

    2015-01-01T23:59:59.000Z

    The ejection dynamics through a nanoscale pore of a flexible polymer that is initially strongly confined inside a spherical capsid is examined. By extensive simulations using the stochastic rotation dynamics method we show that the time for an individual monomer to eject grows exponentially with the number of ejected monomers under constant initial monomer density. This dependence is a consequence of the excess free energy of the polymer due to confinement growing exponentially with the initial monomer number inside the capsid, which we address to strong monomer-monomer interactions. Consequently, for sufficiently strong initial confinement and long polymers ejection times for polymers of different lengths depend linearly on the length. At polymer lengths amenable to computer simulations the dependence is superlinear due to the finite-size effect related to the retraction of polymer tails at final stages of ejection.

  10. Incorporation of H2 in vitreous silica, qualitative and quantitative determination from Raman and infrared

    E-Print Network [OSTI]

    Boyer, Edmond

    the quench. #12;1. Introduction The incorporation of volatiles such as noble gases, carbon dioxide and water properties affected by the presence of the volatiles and their related species in the silicate network (see] and to affect optical properties of vitreous silica [14, 15]. Therefore, the dissolution mechanisms of water

  11. Radiotracer determination of anion diffusion coefficients in the electronically conductive polymer polypyrrole 

    E-Print Network [OSTI]

    Burton, Bruce Lawrence

    1987-01-01T23:59:59.000Z

    RADIOTRACER DETERMINATION OF ANION DIFFUSION COEFFICIENTS IN THE ELECTRONICALLY CONDUCTIVE POLYMER POLYPYRROLE A Thesis by BRUCE LAWRENCE BURTON Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1987 Major Subject: Chemistry RADIOTRACER DETERMINATION OF ANION DIFFUSION COEFFICIENTS IN THE ELECTRONICALLY CONDUCTIVE POLYMER POLYPYRROLE A Thesis BRUCE LAWRENCE BURTON Approved as to style...

  12. Pore-structure determinations of silica aerogels by {sup 129}Xe NMR spectroscopy and imaging.

    SciTech Connect (OSTI)

    Gregory, D. M.; Gerald, R. E., II; Botto, R. E.; Chemistry

    1998-04-01T23:59:59.000Z

    Silica aerogels represent a new class of open-pore materials with pore dimensions on a scale of tens of nanometers, and are thus classified as mesoporous materials. In this work, we show that the combination of NMR spectroscopy and chemical-shift selective magnetic resonance imaging (MRI) can resolve some of the important aspects of the structure of silica aerogels. The use of xenon as a gaseous probe in combination with spatially resolved NMR techniques is demonstrated to be a powerful, new approach for characterizing the average pore structure and steady-state spatial distributions of xenon atoms in different physicochemical environments. Furthermore, dynamic NMR magnetization transfer experiments and pulsed-field gradient (PFG) measurements have been used to characterize exchange processes and diffusive motion of xenon in samples at equilibrium. In particular, this new NMR approach offers unique information and insights into the nanoscopic pore structure and microscopic morphology of aerogels and the dynamical behavior of occluded adsorbates. MRI provides spatially resolved information on the nature of the flaw regions found in these materials. Pseudo-first-order rate constants for magnetization transfer among the bulk and occluded xenon phases indicate xenon-exchange rate constants on the order of 1 s-1 for specimens having volumes of 0.03 cm3. PFG diffusion measurements show evidence of anisotropic diffusion for xenon occluded within aerogels, with nominal self-diffusivity coefficients on the order of D= 10-3cm2/s.

  13. Determining the Density Profile of Confined Polymer Brushes with Neutron Reflectivity

    E-Print Network [OSTI]

    Kuhl, Tonya L.

    , University of South Florida, Florida 33620 3 Manuel Lujan Jr. Neutron Scattering Center, LANSCE-12, MS H805Determining the Density Profile of Confined Polymer Brushes with Neutron Reflectivity W. A. HAMILTON,1 G. S. SMITH,1 N. A. ALCANTAR,2 J. MAJEWSKI,3 R. G. TOOMEY,4 T. L. KUHL5 1 Center for Neutron

  14. Log-Gamma polymer free energy fluctuations via a Fredholm determinant identity

    E-Print Network [OSTI]

    Alexei Borodin; Ivan Corwin; Daniel Remenik

    2012-06-20T23:59:59.000Z

    We prove that under n^{1/3} scaling, the limiting distribution as n goes to infinity of the free energy of Seppalainen's log-Gamma discrete directed polymer is GUE Tracy-Widom. The main technical innovation we provide is a general identity between a class of n-fold contour integrals and a class of Fredholm determinants. Applying this identity to the integral formula proved in [Corwin-O'Connell-Seppalainen-Zygouras] for the Laplace transform of the log-Gamma polymer partition function, we arrive at a Fredholm determinant which lends itself to asymptotic analysis (and thus yields the free energy limit theorem). The Fredholm determinant was anticipated in [Borodin-Corwin] via the formalism of Macdonald processes yet its rigorous proof was so far lacking because of the nontriviality of certain decay estimates required by that approach.

  15. Mass fractal characteristics of silica sonogels as determined by small-angle x-ray scattering and nitrogen adsorption

    SciTech Connect (OSTI)

    Donatti, D.A.; Vollet, D.R.; Ibanez Ruiz, A.; Mesquita, A.; Silva, T.F.P. [Unesp-Universidade Estadual Paulista, IGCE, Departamento de Fisica, P.O. Box 178 CEP, 13500-970 Rio Claro, Sao Paulo (Brazil)

    2005-01-01T23:59:59.000Z

    A sample series of silica sonogels was prepared using different water-tetraethoxysilane molar ratio (r{sub w}) in the gelation step of the process in order to obtain aerogels with different bulk densities after the supercritical drying. The samples were analyzed by means of small-angle x-ray-scattering (SAXS) and nitrogen-adsorption techniques. Wet sonogels exhibit mass fractal structure with fractal dimension D increasing from {approx}2.1 to {approx}2.4 and mass-fractal correlation length {xi} diminishing from {approx}13 nm to {approx}2 nm, as r{sub w} is changed in the nominal range from 66 to 6. The process of obtaining aerogels from sonogels and heat treatment at 500 deg. C, in general, increases the mass-fractal dimension D, diminishes the characteristic length {xi} of the fractal structure, and shortens the fractal range at the micropore side for the formation of a secondary structured particle, apparently evolved from the original wet structure at a high resolution level. The overall mass-fractal dimension D of aerogels was evaluated as {approx}2.4 and {approx}2.5, as determined from SAXS and from pore-size distribution by nitrogen adsorption, respectively. The fine structure of the 'secondary particle' developed in the obtaining of aerogels could be described as a surface-mass fractal, with the correlated surface and mass-fractal dimensions decreasing from {approx}2.4 to {approx}2.0 and from {approx}2.7 to {approx}2.5, respectively, as the aerogel bulk density increases from 0.25 (r{sub w}=66) up to 0.91 g/cm{sup 3} (r{sub w}=6)

  16. High temperature polymer concrete

    DOE Patents [OSTI]

    Fontana, J.J.; Reams, W.

    1984-05-29T23:59:59.000Z

    This invention is concerned with a polymer concrete composition, which is a two-component composition useful with many bases including metal. Component A, the aggregate composition, is broadly composed of silica, silica flour, portland cement, and acrylamide, whereas Component B, which is primarily vinyl and acrylyl reactive monomers, is a liquid system.

  17. Molecular sieving silica membrane fabrication process

    DOE Patents [OSTI]

    Raman, N.K.; Brinker, C.J.

    1999-08-10T23:59:59.000Z

    A process is described for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film. 11 figs.

  18. Mesoporous-silica films, fibers, and powders by evaporation ...

    Office of Scientific and Technical Information (OSTI)

    fiber formation starts with a similar silica precursor solution but with an added pre-polymer making a pituitous mixture that is drawn into a thin strand from which solvent is...

  19. Silica Scaling Removal Process

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    sidestreams of cooling tower water by providing a substrate for the deposition and adsorption of silica. The removal of the silica prevents scaling deposition on heat transfer...

  20. Self-assembled laminated nanoribbon-directed synthesis of noble metallic nanoparticle-decorated silica nanotubes and their catalytic applications

    E-Print Network [OSTI]

    Huang, Jianbin

    such as silica dioxide (SiO2), titanium dioxide (TiO2), carbon nanotube (CNT), graphene, microgel, and polymer.18

  1. Determination of photocarrier density under continuous photoirradiation using spectroscopic techniques as applied to polymer: Fullerene blend films

    SciTech Connect (OSTI)

    Kanemoto, Katsuichi, E-mail: kkane@sci.osaka-cu.ac.jp; Nakatani, Hitomi; Domoto, Shinya [Department of Physics, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan)

    2014-10-28T23:59:59.000Z

    We propose a method to determine the density of photocarrier under continuous photoirradiation in conjugated polymers using spectroscopic signals obtained by photoinduced absorption (PIA) measurements. The bleaching signals in the PIA measurements of polymer films and the steady-state absorption signals of oxidized polymer solution are employed to determine the photocarrier density. The method is applied to photocarriers of poly (3-hexylthiophene) (P3HT) in a blended film consisting of P3HT and [6,6]-phenyl C61 butyric acid methyl ester (PCBM). The photocarrier density under continuous photoirradiation of 580 mW/cm{sup 2} is determined to be 3.5?×?10{sup 16?}cm{sup ?3}. Using a trend of the carrier density increasing in proportion to the square root of photo-excitation intensity, we provide a general formula to estimate the photocarrier density under simulated 1 sun solar irradiation for the P3HT: PCBM film of an arbitrary thickness. We emphasize that the method proposed in this study enables an estimate of carrier density without measuring a current and can be applied to films with no electrodes as well as to devices.

  2. High temperature polymer concrete compositions

    DOE Patents [OSTI]

    Fontana, Jack J. (Shirley, NY); Reams, Walter (Shirley, NY)

    1985-01-01T23:59:59.000Z

    This invention is concerned with a polymer concrete composition, which is a two-component composition useful with many bases including metal. Component A, the aggregate composition, is broadly composed of silica, silica flour, portland cement, and acrylamide, whereas Component B, which is primarily vinyl and acrylyl reactive monomers, is a liquid system. A preferred formulation emphasizing the major necessary components is as follows: ______________________________________ Component A: Silica sand 60-77 wt. % Silica flour 5-10 wt. % Portland cement 15-25 wt. % Acrylamide 1-5 wt. % Component B: Styrene 50-60 wt. % Trimethylolpropane 35-40 wt. % trimethacrylate ______________________________________ and necessary initiators, accelerators, and surfactants.

  3. Kinetics of Silica Polymerization

    E-Print Network [OSTI]

    Weres, Oleh

    2011-01-01T23:59:59.000Z

    geothermal brines:’ Avoidance or minimization of silica supersaturation Supersaturation can be avoided by preventing cooling

  4. Conversion of geothermal waste to commercial products including silica

    DOE Patents [OSTI]

    Premuzic, Eugene T. (East Moriches, NY); Lin, Mow S. (Rocky Point, NY)

    2003-01-01T23:59:59.000Z

    A process for the treatment of geothermal residue includes contacting the pigmented amorphous silica-containing component with a depigmenting reagent one or more times to depigment the silica and produce a mixture containing depigmented amorphous silica and depigmenting reagent containing pigment material; separating the depigmented amorphous silica and from the depigmenting reagent to yield depigmented amorphous silica. Before or after the depigmenting contacting, the geothermal residue or depigmented silica can be treated with a metal solubilizing agent to produce another mixture containing pigmented or unpigmented amorphous silica-containing component and a solubilized metal-containing component; separating these components from each other to produce an amorphous silica product substantially devoid of metals and at least partially devoid of pigment. The amorphous silica product can be neutralized and thereafter dried at a temperature from about 25.degree. C. to 300.degree. C. The morphology of the silica product can be varied through the process conditions including sequence contacting steps, pH of depigmenting reagent, neutralization and drying conditions to tailor the amorphous silica for commercial use in products including filler for paint, paper, rubber and polymers, and chromatographic material.

  5. Log-Gamma Polymer Free Energy Fluctuations via a Fredholm Determinant Identity

    E-Print Network [OSTI]

    Borodin, Alexei

    We prove that under n[superscript 1/3] scaling, the limiting distribution as n ? ? of the free energy of Seppalainen’s log-Gamma discrete directed polymer is GUE Tracy-Widom. The main technical innovation we provide is a ...

  6. Cellular membrane trafficking of mesoporous silica nanoparticles

    SciTech Connect (OSTI)

    Fang, I-Ju

    2012-06-21T23:59:59.000Z

    This dissertation mainly focuses on the investigation of the cellular membrane trafficking of mesoporous silica nanoparticles. We are interested in the study of endocytosis and exocytosis behaviors of mesoporous silica nanoparticles with desired surface functionality. The relationship between mesoporous silica nanoparticles and membrane trafficking of cells, either cancerous cells or normal cells was examined. Since mesoporous silica nanoparticles were applied in many drug delivery cases, the endocytotic efficiency of mesoporous silica nanoparticles needs to be investigated in more details in order to design the cellular drug delivery system in the controlled way. It is well known that cells can engulf some molecules outside of the cells through a receptor-ligand associated endocytosis. We are interested to determine if those biomolecules binding to cell surface receptors can be utilized on mesoporous silica nanoparticle materials to improve the uptake efficiency or govern the mechanism of endocytosis of mesoporous silica nanoparticles. Arginine-glycine-aspartate (RGD) is a small peptide recognized by cell integrin receptors and it was reported that avidin internalization was highly promoted by tumor lectin. Both RGD and avidin were linked to the surface of mesoporous silica nanoparticle materials to investigate the effect of receptor-associated biomolecule on cellular endocytosis efficiency. The effect of ligand types, ligand conformation and ligand density were discussed in Chapter 2 and 3. Furthermore, the exocytosis of mesoporous silica nanoparticles is very attractive for biological applications. The cellular protein sequestration study of mesoporous silica nanoparticles was examined for further information of the intracellular pathway of endocytosed mesoporous silica nanoparticle materials. The surface functionality of mesoporous silica nanoparticle materials demonstrated selectivity among the materials and cancer and normal cell lines. We aimed to determine the specific organelle that mesoporous silica nanoparticles could approach via the identification of harvested proteins from exocytosis process. Based on the study of endo- and exocytosis behavior of mesoporous silica nanoparticle materials, we can design smarter drug delivery vehicles for cancer therapy that can be effectively controlled. The destination, uptake efficiency and the cellular distribution of mesoporous silica nanoparticle materials can be programmable. As a result, release mechanism and release rate of drug delivery systems can be a well-controlled process. The deep investigation of an endo- and exocytosis study of mesoporous silica nanoparticle materials promotes the development of drug delivery applications.

  7. Silica extraction from geothermal water

    DOE Patents [OSTI]

    Bourcier, William L; Bruton, Carol J

    2014-09-23T23:59:59.000Z

    A method of producing silica from geothermal fluid containing low concentration of the silica of less than 275 ppm includes the steps of treating the geothermal fluid containing the silica by reverse osmosis treatment thereby producing a concentrated fluid containing the silica, seasoning the concentrated fluid thereby producing a slurry having precipitated colloids containing the silica, and separating the silica from the slurry.

  8. Silica in Protoplanetary Disks

    E-Print Network [OSTI]

    B. A. Sargent; W. J. Forrest; C. Tayrien; M. K. McClure; A. Li; A. R. Basu; P. Manoj; D. M. Watson; C. J. Bohac; E. Furlan; K. H. Kim; J. D. Green; G. C. Sloan

    2008-11-21T23:59:59.000Z

    Mid-infrared spectra of a few T Tauri stars (TTS) taken with the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope show prominent narrow emission features indicating silica (crystalline silicon dioxide). Silica is not a major constituent of the interstellar medium; therefore, any silica present in the circumstellar protoplanetary disks of TTS must be largely the result of processing of primitive dust material in the disks surrouding these stars. We model the silica emission features in our spectra using the opacities of various polymorphs of silica and their amorphous versions computed from earth-based laboratory measurements. This modeling indicates that the two polymorphs of silica, tridymite and cristobalite, which form at successively higher temperatures and low pressures, are the dominant forms of silica in the TTS of our sample. These high temperature, low pressure polymorphs of silica present in protoplanetary disks are consistent with a grain composed mostly of tridymite named Ada found in the cometary dust samples collected from the STARDUST mission to Comet 81P/Wild 2. The silica in these protoplanetary disks may arise from incongruent melting of enstatite or from incongruent melting of amorphous pyroxene, the latter being analogous to the former. The high temperatures of 1200K-1300K and rapid cooling required to crystallize tridymite or cristobalite set constraints on the mechanisms that could have formed the silica in these protoplanetary disks, suggestive of processing of these grains during the transient heating events hypothesized to create chondrules.

  9. Modification of Silica Nanoparticles by Grafting of Copolymers Containing Organosilane and Fluorine Moities.

    E-Print Network [OSTI]

    Boyer, Edmond

    .23513 #12;2 Introduction Organic polymer / inorganic hybrid nanocomposites are of current research/silica weight ratio until a maximum value of 2.26 mol.m-2 . Keywords: cotelomerization; grafting onto; hybrid nanoparticle; perfluoroacrylate; silica nanocomposite. hal-00412444,version1-1Sep2009 Author manuscript

  10. Evacuated Panels Utilizing Clay-Polymer Aerogel Composites for Improved Housing Insulation

    E-Print Network [OSTI]

    Rollins, Andrew M.

    Evacuated Panels Utilizing Clay-Polymer Aerogel Composites for Improved Housing Insulation March 17 encompasses a newly developed clay-polymer aerogel composite material (developed and patented by Dr. David Aerogel ~22 > 2,500 Silica Aerogel Blanket 10 1,800 (Aspen Aerogel) Silica Aerogel / PP Evacuated Panel 50

  11. Determination of structure and phase transition of light element nanocomposites in mesoporous silica: case study of NH3BH3 in MCM-41

    SciTech Connect (OSTI)

    Kim, Hyun Jeong; Karkamkar, Abhijeet J.; Autrey, Thomas; Chupas, Peter; Proffen, Thomas E.

    2009-09-30T23:59:59.000Z

    The structure of ammonia borane (AB), NH3BH3, infused in mesoporous silica MCM-41 and its evolution over the temperature range of 80 to 300 K was investigated using the atomic pair distribution function (PDF) analysis of synchrotron X-ray powder diffraction data in order to understand the origin of improved dehydrogenation properties of the system. Our study shows how X-ray PDF analysis can be used to elucidate the structure of light guest species loaded in mesoporous silica materials despite of its low scattering power of composed elements (N, B, and H) compared to its host (SiO2). PDF analyses of two AB-loaded compositions with weight ratio AB:MCM-41=1:1 and 3:1 provide a strong evidence that AB aggregate, previously found in AB:MCM-41?1:1 samples, is same species as neat AB. For both of them an orthorhombic to tetragonal structural phase transition occurs at 225 K on warming. On the other hand, AB residing inside meso-pores, which is found in AB:MCM-41=1:2 sample, does not undergo such phase transition. It rather stays in tetragonal phase over a wide temperature range of 110 to 240 K and starts to lose structural correlation above 240 K. This strongly suggests that nano-confinement of AB inside meso-pores stabilizes high temperature tetragonal phase at much lower temperature. These results provide important clues to two critical questions: why nan-compositions of AB leads dehydrogenation to lower temperature and why the neat AB like propoerties are recovered at high AB loading samples. This work was supported by the US Department of Energy Office of Basic Energy Sciences, Chemical Sciences program. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  12. CX-010520: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Silica Polymer Initiator Conformance Gel Applications in Geothermal Zonal Isolation CX(s) Applied: A9, B3.6, B3.11 Date: 06/17/2013 Location(s): Oklahoma Offices(s): Golden Field Office

  13. CX-007409: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Silica Polymer Initiator Conformance Gel Applications in Geothermal Zonal Isolation CX(s) Applied: A9, B3.6 Date: 12/21/2011 Location(s): Oklahoma Offices(s): Golden Field Office

  14. Kinetics of Silica Polymerization

    E-Print Network [OSTI]

    Weres, Oleh

    2011-01-01T23:59:59.000Z

    The Chemistry of Silica in Cerro Prieto Brines". Report LBL-the United States, Cerro Prieto and n Mexico, and WairakeiProgram .of DGE through the Cerro Prieto Research Project at

  15. Polymer films

    DOE Patents [OSTI]

    Granick, Steve (Champaign, IL); Sukhishvili, Svetlana A. (Maplewood, NJ)

    2008-12-30T23:59:59.000Z

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  16. Functionalized mesoporous silica nanoparticles for oral delivery of budesonide

    SciTech Connect (OSTI)

    Yoncheva, K., E-mail: krassi.yoncheva@gmail.com [Department of Pharmaceutical Technology, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000 Sofia (Bulgaria); Popova, M. [Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia (Bulgaria); Szegedi, A.; Mihaly, J. [Institute of Nanochemistry and Catalysis, Chemical Research Center, Hungarian Academy of Sciences, Pusztaszeri út. 59-67, 1025 Budapest (Hungary); Tzankov, B.; Lambov, N.; Konstantinov, S.; Tzankova, V. [Department of Pharmaceutical Technology, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000 Sofia (Bulgaria); Pessina, F.; Valoti, M. [Dipartimento di Scienze della Vita, Universita di Siena, via Aldo Moro 2, Siena (Italy)

    2014-03-15T23:59:59.000Z

    Non-functionalized and amino-functionalized mesoporous silica nanoparticle were loaded with anti-inflammatory drug budesonide and additionally post-coated with bioadhesive polymer (carbopol). TEM images showed spherical shape of the nanoparticles and slightly higher polydispersity after coating with carbopol. Nitrogen physisorption and thermogravimetic analysis revealed that more efficient loading and incorporation into the pores of nanoparticles was achieved with the amino-functionalized silica carrier. Infrared spectra indicated that the post-coating of these nanoparticles with carbopol led to the formation of bond between amino groups of the functionalized carrier and carboxyl groups of carbopol. The combination of amino-functionalization of the carrier with the post-coating of the nanoparticles sustained budesonide release. Further, an in vitro model of inflammatory bowel disease showed that the cytoprotective effect of budesonide loaded in the post-coated silica nanoparticles on damaged HT-29 cells was more pronounced compared to the cytoprotection obtained with pure budesonide. -- Graphical abstract: Silica mesoporous MCM-41 particles were amino-functionalized, loaded with budesonide and post-coated with bioadhesive polymer (carbopol) in order to achieve prolonged residence of anti-inflammatory drug in GIT. Highlights: • Higher drug loading in amino-functionalized mesoporous silica. • Amino-functionalization and post-coating of the nanoparticles sustained drug release. • Achievement of higher cytoprotective effect with drug loaded into the nanoparticles.

  17. Silica recovery and control in Hawaiian geothermal fluids

    SciTech Connect (OSTI)

    Thomas, D.M.

    1992-06-01T23:59:59.000Z

    A series of experiments was performed to investigate methods of controlling silica in waste geothermal brines produced at the HGP-A Generator Facility. Laboratory testing has shown that the rate of polymerization of silica in the geothermal fluids is highly pH dependent. At brine pH values in excess of 8.5 the suspension of silica polymers flocculated and rapidly precipitated a gelatinous silica mass. Optimum flocculation and precipitation rates were achieved at pH values in the range of 10.5 to 11.5. The addition of transition metal salts to the geothermal fluids similarly increased the rate of polymerization as well as the degree of precipitation of the silica polymer from suspension. A series of experiments performed on the recovered silica solids demonstrated that methanol extraction of the water in the gels followed by critical point drying yielded surface areas in excess of 300 M{sup 2}/g and that treatment of the dried solids with 2 N HCl removed most of the adsorbed impurities in the recovered product. A series of experiments tested the response of the waste brines to mixing with steam condensate and non-condensable gases.The results demonstrated that the addition of condensate and NCG greatly increased the stability of the silica in the geothermal brines. They also indicated that the process could reduce the potential for plugging of reinjection wells receiving waste geothermal fluids from commercial geothermal facilities in Hawaii. Conceptual designs were proposed to apply the gas re-combination approach to the disposal of geothermal waste fluids having a range of chemical compositions. Finally, these designs were applied to the geothermal fluid compositions found at Cerro Prieto, Ahuachapan, and Salton Sea.

  18. Silica recovery and control in Hawaiian geothermal fluids. Final report

    SciTech Connect (OSTI)

    Thomas, D.M.

    1992-06-01T23:59:59.000Z

    A series of experiments was performed to investigate methods of controlling silica in waste geothermal brines produced at the HGP-A Generator Facility. Laboratory testing has shown that the rate of polymerization of silica in the geothermal fluids is highly pH dependent. At brine pH values in excess of 8.5 the suspension of silica polymers flocculated and rapidly precipitated a gelatinous silica mass. Optimum flocculation and precipitation rates were achieved at pH values in the range of 10.5 to 11.5. The addition of transition metal salts to the geothermal fluids similarly increased the rate of polymerization as well as the degree of precipitation of the silica polymer from suspension. A series of experiments performed on the recovered silica solids demonstrated that methanol extraction of the water in the gels followed by critical point drying yielded surface areas in excess of 300 M{sup 2}/g and that treatment of the dried solids with 2 N HCl removed most of the adsorbed impurities in the recovered product. A series of experiments tested the response of the waste brines to mixing with steam condensate and non-condensable gases.The results demonstrated that the addition of condensate and NCG greatly increased the stability of the silica in the geothermal brines. They also indicated that the process could reduce the potential for plugging of reinjection wells receiving waste geothermal fluids from commercial geothermal facilities in Hawaii. Conceptual designs were proposed to apply the gas re-combination approach to the disposal of geothermal waste fluids having a range of chemical compositions. Finally, these designs were applied to the geothermal fluid compositions found at Cerro Prieto, Ahuachapan, and Salton Sea.

  19. Kinetics of silica polymerization

    SciTech Connect (OSTI)

    Weres, O.; Yee, A.; Tsao, L.

    1980-05-01T23:59:59.000Z

    The polymerization of silicic acid in geothermal brine-like aqueous solutions to produce amorphous silica in colloidal form has been studied experimentally and theoretically. A large amount of high quality experimental data has been generated over the temperature rang 23 to 100{sup 0}C. Wide ranges of dissolved silica concentration, pH, and sodium chloride concentration were covered. The catalytic effects of fluoride and the reaction inhibiting effects of aluminum and boron were studied also. Two basic processes have been separately studied: the formation of new colloidal particles by the homogeneous nucleation process and the deposition of dissolved silica on pre-existing colloidal particles. A rigorous theory of the formation of colloidal particles of amorphous silica by homogeneous nucleation was developed. This theory employs the Lothe-Pound formalism, and is embodied in the computer code SILNUC which quantitatively models the homogeneous nucleation and growth of colloidal silica particles in more than enough detail for practical application. The theory and code were extensively used in planning the experimental work and analyzing the data produced. The code is now complete and running in its final form. It is capable of reproducing most of the experimental results to within experimental error. It is also capable of extrapolation to experimentally inaccessible conditions, i.e., high temperatures, rapidly varying temperature and pH, etc.

  20. Mesoporous-silica films, fibers, and powders by evaporation

    DOE Patents [OSTI]

    Bruinsma, P.J.; Baskaran, S.; Bontha, J.R.; Liu, J.

    1999-07-13T23:59:59.000Z

    This invention pertains to surfactant-templated nanometer-scale porosity of a silica precursor solution and forming a mesoporous material by first forming the silica precursor solution into a preform having a high surface area to volume ratio, then rapid drying or evaporating a solvent from the silica precursor solution. The mesoporous material may be in any geometric form, but is preferably in the form of a film, fiber, powder or combinations thereof. The rapid drying or evaporation of solvent from the solution is accomplished by layer thinning, for example spin casting, liquid drawing, and liquid spraying respectively. Production of a film is by layer thinning, wherein a layer of the silica precursor solution is formed on a surface followed by removal of an amount of the silica precursor solution and leaving a geometrically thinner layer of the silica precursor solution from which the solvent quickly escapes via evaporation. Layer thinning may be by any method including but not limited to squeegeeing and/or spin casting. In powder formation by spray drying, the same conditions of fast drying exists as in spin-casting (as well as in fiber spinning) because of the high surface-area to volume ratio of the product. When a powder is produced by liquid spraying, the particles or micro-bubbles within the powder are hollow spheres with walls composed of mesoporous silica. Mesoporous fiber formation starts with a similar silica precursor solution but with an added pre-polymer making a pituitous mixture that is drawn into a thin strand from which solvent is evaporated leaving the mesoporous fiber(s). 24 figs.

  1. Compressive Strength of Gamma-Irradiated Polymer Concrete

    E-Print Network [OSTI]

    North Texas, University of

    Compressive Strength of Gamma-Irradiated Polymer Concrete Gonzalo Marti´nez-Barrera,1,2 Uriel concrete (PC) was developed by using differ- ent concentrations of silica sand as aggregate of Plastics Engineers INTRODUCTION Polymer concrete (PC) is a particulate composite where thermoset resins

  2. A plasmonically enhanced polymer solar cell with goldsilica coreshell nanorods

    E-Print Network [OSTI]

    Xiong, Qihua

    to conventional silicon solar cells due to the low-cost materi- als, mechanical flexibility and solutionA plasmonically enhanced polymer solar cell with gold­silica core­shell nanorods Xiaoyan Xu: Polymer solar cells Au nanorods Metallic nanoparticles Plasmonic effects a b s t r a c t We report the use

  3. Quantification of residual stress from photonic signatures of fused silica

    SciTech Connect (OSTI)

    Cramer, K. Elliott; Yost, William T. [NASA Langley Research Center, Hampton, VA 23681 (United States); Hayward, Maurice [College of William and Mary, Williamsburg, VA 23185 (United States)

    2014-02-18T23:59:59.000Z

    A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outer-most pane of Space Shuttle windows made from fused silica. A method and apparatus for calibration of the stress-optic coefficient using four-point bending is discussed. The results are validated on known material (acrylic) and are found to agree with literature values to within 6%. The calibration procedure is then applied to fused-silica specimens and the stress-optic coefficient is determined to be 2.43 ± 0.54 × 10{sup ?12} Pa{sup ?1}. Fused silica specimens containing impacts artificially made at NASA’s Hypervelocity Impact Technology Facility (HIT-F), to simulate damage typical during space flight, are examined. The damage sites are cored from fused silica window carcasses and examined with the GFP. The calibrated GFP measurements of residual stress patterns surrounding the damage sites are presented.

  4. Exceptional properties of semi-dilute solutions of nanoparticle laden polymers in water

    E-Print Network [OSTI]

    Joseph, Daniel D.

    National Laboratory. Advanced Photon Source, Argonne IL January 2005 Dr. Wang will lead studies discovered properties of semi-dilute aqueous solutions of composite polymers of polyethylene oxide and silica with exceptional properties is created by the absorption of the polyethylene oxide onto the silica nanoparticles

  5. Characterization of the intrinsic strength between epoxy and silica using a multiscale approach

    E-Print Network [OSTI]

    Buehler, Markus J.

    , we report a model to predict the intrinsic strength between organic and inorganic materials, based energy surface between attached and detached states of the bonded system and scaled up to incorporate readily in many other polymers. Silica, commonly found material in nature in the form of sand or quartz

  6. Some Rigorous Results on Semiflexible Polymers I. Free and confined polymers

    E-Print Network [OSTI]

    Velenik, Yvan

    Some Rigorous Results on Semiflexible Polymers I. Free and confined polymers O. Hryniva , Y 4, Switzerland Abstract We introduce a class of models of semiflexible polymers. The latter, called the persistence length, being of the same order as the polymer length. We determine

  7. Durable polymer-aerogel based superhydrophobic coatings, a composite material

    DOE Patents [OSTI]

    Kissel, David J; Brinker, Charles Jeffrey

    2014-03-04T23:59:59.000Z

    Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140.degree. and a contact angle hysteresis of less than about 1.degree.. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

  8. Polymer Filler Aging and Failure Studied by Lateral Force Microscopy

    SciTech Connect (OSTI)

    Ratto, T; Saab, A P

    2009-05-27T23:59:59.000Z

    In the present work, we study, via force microscopy, the basic physical interactions of a single bead of silica filler with a PDMS matrix both before and after exposure to gamma radiation. Our goal was to confirm our results from last year, and to explore force microscopy as a means of obtaining particle-scale polymer/filler interactions suitable for use as empirical inputs to a computational model consisting of an ensemble of silica beads embedded in a PDMS matrix. Through careful calibration of a conventional atomic force microscope, we obtained both normal and lateral force data that was fitted to yield adhesion, surface shear modulus, and friction of a 1 {micro}m silica bead in contact with PDMS layers of various thickness. Comparison of these terms before and after gamma exposure indicated that initially, radiation exposure lead to softening of the PDMS, but eventually resulted in stiffening. Simultaneously, adhesion between the polymer and silica decreased. This could indicate a serious failure path for filled PDMS exposed to radiation, whereby stiffening of the bulk polymer leads to loss of compressive elastic behavior, while a decrease in polymer filler adhesion results in an increased likelihood of stress failure under load. In addition to further testing of radiation damaged polymers, we also performed FEA modeling of silica beads in a silicone matrix using the shear modulus and adhesion values isolated from the force microscopy experiments as model inputs. The resulting simulation indicated that as a polymer stiffens due to impinging radiation, it also undergoes weakening of adhesion to the filler. The implication is that radiation induces a compound failure mode in filled polymer systems.

  9. Development of 3-D magnetic nano-arrays by electrodeposition into mesoporous silica.

    SciTech Connect (OSTI)

    Campbell, R.; Manning, J.; Bakker, M.G.; Li, X.; Lee, D.R.; Wang, J.; X-Ray Science Division; Univ. of Alabama

    2006-01-01T23:59:59.000Z

    The development of periodic nanostructures fabricated by self-assembly of surfactants and block co-polymers has opened up the possibility of generating periodic magnetic nanostructures of types not accessible by self-assembly of nano-particles. The fabrication of mesoporous silica thin films around self-assembled block co-polymers is well established. Common structures for such films are SBA-15 which consists of hexagonal arrays of cylindrical pores and SBA-16 which has face centered arrays of spherical voids. These pores are connected by 1-2 nm thick flaws in the continuous silica phase producing an effectively continuous porous phase. After removal of the block co-polymer template, electrodeposition into the mesoporous silica thin films produces arrays of 5-10 nm diameter nano-wires and nano-particles. We have demonstrated that such materials can be fabricated on a wide range of metal substrates. Characterization by Scanning Electron Microscopies shows that the mesoporous silica is well ordered over micron scale areas. Grazing Incidence Small Angle X-ray Scattering (GISAXS) studies shows diffraction spots, consistent with the entire film being well ordered. GISAXS also shows that the mesoporous silica films survive removal of the template and electrodeposition of nickel and cobalt into the mesoporous silica films. Such films are of interest for their magnetic properties, as the nanophase and scale can be independently varied. Further, the presence of nanowires inside an insulator suggests that these films might also be of interest as the current confining element for Confined Current Path-Current Perpendicular to Plane GMR sensors.

  10. Propagation of polymer slugs through porous media

    SciTech Connect (OSTI)

    Lecourtier, J.; Chauveteau, G.

    1984-09-01T23:59:59.000Z

    This paper describes an experimental and theoretical study of the mechanisms governing polymer slug propagation through porous media. An analytical model taking into account the macromolecule exclusion from pore walls is proposed to predict rodlike polymer velocity in porous media and thus the spreading out of polydispersed polymer slugs. Under conditions where this wall exclusion is maximum, i.e. at low shear rates and polymer concentrations, the experiments show that xanthan propagation is effectively predicted by this model. At higher flow rates and polymer concentrations, the effects of hydrodynamic dispersion and viscous fingering are analyzed. A new fractionation method for determining molecular weight distribution of polymers used in EOR is proposed.

  11. Antireflective graded index silica coating, method for making

    DOE Patents [OSTI]

    Yoldas, Bulent E. (Churchill, PA); Partlow, Deborah P. (Wilkinsburg, PA)

    1985-01-01T23:59:59.000Z

    Antireflective silica coating for vitreous material is substantially non-reflecting over a wide band of radiations. This is achieved by providing the coating with a graded degree of porosity which grades the index of refraction between that of air and the vitreous material of the substrate. To prepare the coating, there is first prepared a silicon-alkoxide-based coating solution of particular polymer structure produced by a controlled proportion of water to alkoxide and a controlled concentration of alkoxide to solution, along with a small amount of catalyst. The primary solvent is alcohol and the solution is polymerized and hydrolized under controlled conditions prior to use. The prepared solution is applied as a film to the vitreous substrate and rapidly dried. It is thereafter heated under controlled conditions to volatilize the hydroxyl radicals and organics therefrom and then to produce a suitable pore morphology in the residual porous silica layer. The silica layer is then etched in order to enlarge the pores in a graded fashion, with the largest of the pores remaining being sufficiently small that radiations to be passed through the substrate are not significantly scattered. For use with quartz substrates, extremely durable coatings which display only 0.1% reflectivity have been prepared.

  12. Removal of dissolved and colloidal silica

    DOE Patents [OSTI]

    Midkiff, William S. (Ruidoso, NM)

    2002-01-01T23:59:59.000Z

    Small amorphous silica particles are used to provide a relatively large surface area upon which silica will preferentially adsorb, thereby preventing or substantially reducing scaling caused by deposition of silica on evaporative cooling tower components, especially heat exchange surfaces. The silica spheres are contacted by the cooling tower water in a sidestream reactor, then separated using gravity separation, microfiltration, vacuum filtration, or other suitable separation technology. Cooling tower modifications for implementing the invention process have been designed.

  13. Stabilized fuel with silica support structure

    SciTech Connect (OSTI)

    Poco, J.F.; Hrubesh, L.W.

    1991-12-31T23:59:59.000Z

    This report describes a stabilized fuel which is supported by a silica support structure. The silica support structure provides a low density, high porosity vehicle for safely carrying hydrocarbon fuels. The silica support structure for hydrocarbon fuel does not produce toxic material residues on combustion which would pose environmentally sensitive disposal problems. The silica stabilized fuel composition is useful as a low temperature, continuous burning fire starter for wood or charcoal.

  14. Control of Polymer Structures in Phase-Separated Liquid Crystal-Polymer Composite Systems Qingbing WANG, Jung O. PARK1

    E-Print Network [OSTI]

    Srinivasarao, Mohan

    Control of Polymer Structures in Phase-Separated Liquid Crystal-Polymer Composite Systems Qingbing, Kent State University, Kent, OH 44242, USA 1 School of Polymer, Textile and Fiber Engineering and diffusion of small molecules, play important roles in determining a specific PSCOF polymer structure

  15. Moisture sensor based on evanescent wave light scattering by porous sol-gel silica coating

    DOE Patents [OSTI]

    Tao, Shiquan; Singh, Jagdish P.; Winstead, Christopher B.

    2006-05-02T23:59:59.000Z

    An optical fiber moisture sensor that can be used to sense moisture present in gas phase in a wide range of concentrations is provided, as well techniques for making the same. The present invention includes a method that utilizes the light scattering phenomenon which occurs in a porous sol-gel silica by coating an optical fiber core with such silica. Thus, a porous sol-gel silica polymer coated on an optical fiber core forms the transducer of an optical fiber moisture sensor according to an embodiment. The resulting optical fiber sensor of the present invention can be used in various applications, including to sense moisture content in indoor/outdoor air, soil, concrete, and low/high temperature gas streams.

  16. Dielectric Actuation of Polymers

    E-Print Network [OSTI]

    Niu, Xiaofan

    2013-01-01T23:59:59.000Z

    S. Stanford, Interpenetrating polymer networks for high-based on interpenetrating polymer networks, Proceeding ofX. Niu, Q. Pei, Interpenetrating polymer networks based on

  17. Some Rigorous Results on Semiflexible Polymers. I. Free and confined polymers

    E-Print Network [OSTI]

    Ostap Hryniv; Yvan Velenik

    2009-04-20T23:59:59.000Z

    We introduce a class of models of semiflexible polymers. The latter are characterized by a strong rigidity, the correlation length associated to the gradient-gradient correlations, called the persistence length, being of the same order as the polymer length. We determine the macroscopic scaling limit, from which we deduce bounds on the free energy of a polymer confined inside a narrow tube.

  18. Branched Polymers

    E-Print Network [OSTI]

    Richard Kenyon; Peter Winkler

    2007-09-14T23:59:59.000Z

    Building on and from the work of Brydges and Imbrie, we give an elementary calculation of the volume of the space of branched polymers of order $n$ in the plane and in 3-space. Our development reveals some more general identities, and allows exact random sampling. In particular we show that a random 3-dimensional branched polymer of order $n$ has diameter of order $\\sqrt{n}$.

  19. A New Concept for the Fabrication of Hydrogen Selective Silica Membranes

    SciTech Connect (OSTI)

    Michael Tsapatsis

    2006-07-31T23:59:59.000Z

    We are attempting to fabricate H{sub 2}-selective silica-based films by ''layer-by-layer'' deposition as a new approach for thin films. A sonication-assisted deposition method was mainly used for ''layer-by-layer'' deposition. In addition, other approaches such as a dip-coating and the use of a polymer matrix with a layered silicate were contrived as well. This report shows the progress done during the 2nd Year of this award.

  20. Determination

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign: Potential Application to ARM MeasurementsDetermination of

  1. Study of polymer molecules and conformations with a nanopore

    DOE Patents [OSTI]

    Golovchenko, Jene A. (Lexington, MA); Li, Jiali (Fayetteville, AR); Stein, Derek (Delft, NL); Gershow, Marc H. (Cambridge, MA)

    2010-12-07T23:59:59.000Z

    The invention features methods for evaluating the conformation of a polymer, for example, for determining the conformational distribution of a plurality of polymers and to detect binding or denaturation events. The methods employ a nanopore which the polymer, e.g., a nucleic acid, traverses. As the polymer traverses the nanopore, measurements of transport properties of the nanopore yield data on the conformation of the polymer.

  2. Study of polymer molecules and conformations with a nanopore

    DOE Patents [OSTI]

    Golovchenko, Jene A.; Li, Jiali; Stein, Derek; Gershow, Marc H.

    2013-03-12T23:59:59.000Z

    The invention features methods for evaluating the conformation of a polymer, for example, for determining the conformational distribution of a plurality of polymers and to detect binding or denaturation events. The methods employ a nanopore which the polymer, e.g., a nucleic acid, traverses. As the polymer traverses the nanopore, measurements of transport properties of the nanopore yield data on the conformation of the polymer.

  3. Anion exchange polymer electrolytes

    DOE Patents [OSTI]

    Kim, Yu Seung; Kim, Dae Sik

    2013-09-10T23:59:59.000Z

    Solid anion exchange polymer electrolytes include chemical compounds comprising a polymer backbone with side chains that include guanidinium cations.

  4. Antimicrobial Polymer

    DOE Patents [OSTI]

    McDonald, William F. (Utica, OH); Wright, Stacy C. (Flint, MI); Taylor, Andrew C. (Ann Arbor, MI)

    2004-09-28T23:59:59.000Z

    A polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial are disclosed. The polymeric composition comprises a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from metals, metal alloys, metal salts, metal complexes and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups. In one example embodiment, the polymer is a polyamide formed from a maleic anhydride or maleic acid ester monomer and alkylamines thereby producing a polyamide having amino substituted alkyl chains on one side of the polyamide backbone; the crosslinking agent is a phosphine having the general formula (A).sub.3 P wherein A is hydroxyalkyl; and the metallic antimicrobial agent is selected from chelated silver ions, silver metal, chelated copper ions, copper metal, chelated zinc ions, zinc metal and mixtures thereof.

  5. Antimocrobial Polymer

    DOE Patents [OSTI]

    McDonald, William F. (Utica, OH); Huang, Zhi-Heng (Walnut Creek, CA); Wright, Stacy C. (Columbus, GA)

    2005-09-06T23:59:59.000Z

    A polymeric composition having antimicrobial properties and a process for rendering the surface of a substrate antimicrobial are disclosed. The composition comprises a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, (ii) an antimicrobial agent selected from quaternary ammonium compounds, gentian violet compounds, substituted or unsubstituted phenols, biguanide compounds, iodine compounds, and mixtures thereof, and (iii) a crosslinking agent containing functional groups capable of reacting with the amino groups. In one embodiment, the polymer is a polyamide formed from a maleic anhydride or maleic acid ester monomer and alkylamines thereby producing a polyamide having amino substituted alkyl chains on one side of the polyamide backbone; the crosslinking agent is a phosphine having the general formula (A)3P wherein A is hydroxyalkyl; and the antimicrobial agent is chlorhexidine, dimethylchlorophenol, cetyl pyridinium chloride, gentian violet, triclosan, thymol, iodine, and mixtures thereof.

  6. Polymer inflation

    E-Print Network [OSTI]

    Syed Moeez Hassan; Viqar Husain; Sanjeev S. Seahra

    2015-03-05T23:59:59.000Z

    We consider the semi-classical dynamics of a free massive scalar field in a homogeneous and isotropic cosmological spacetime. The scalar field is quantized using the polymer quantization method assuming that it is described by a gaussian coherent state. For quadratic potentials, the semi-classical equations of motion yield a universe that has an early "polymer inflation" phase which is generic and almost exactly de Sitter, followed by a epoch of slow-roll inflation. We compute polymer corrections to the slow roll formalism, and discuss the probability of inflation in this model using a physical Hamiltonian arising from time gauge fixing. We also show how in this model, it is possible to obtain a significant amount of slow-roll inflation from sub-Planckain initial data, hence circumventing some of the criticisms of standard scenarios. These results show the extent to which a quantum gravity motivated quantization method affects early universe dynamics.

  7. Treatment of domestic wastewater for reuse with activated silica and magnesia

    E-Print Network [OSTI]

    Lindner, John Howard

    1985-01-01T23:59:59.000Z

    which are of concern in treat- ment for potable purposes are organics and trace inorganics. This research project was conducted in an attempt to determine if organic oxides such as activated silica and magnesia in various combinations with alum... in Wastewater Toxic Inorganics in Wastewater Existing Technology Coagulation and Flocculation Lime Coagulation . . ~ Alum Coagulation . ~ ~ ~ ~ Activated Silica Magnesia 5 6 8 9 10 13 14 15 16 III EXPERIMENTAL PLAN Was tewater ~ ~ ~ ~ ~ Jar...

  8. Chemistry of Silica in Cerro Prieto Brines

    E-Print Network [OSTI]

    Weres, Oleh

    2012-01-01T23:59:59.000Z

    LBL-10166 CERRO-PRIETO-12 XICAN-AMERICANCOOPERATIVE' PROGRAM T THE CERRO PRIETO GEOTHERMAL FIELD ICHEMISTRY OF SILICA IN CERRO PRIETO BRINES Oleh Weres Leon

  9. Chemistry of Silica in Cerro Prieto Brines

    E-Print Network [OSTI]

    Weres, O.

    2010-01-01T23:59:59.000Z

    LBL-10166 CERRO-PRIETO-12 XICAN-AMERICANCOOPERATIVE' PROGRAM T THE CERRO PRIETO GEOTHERMAL FIELD ICHEMISTRY OF SILICA IN CERRO PRIETO BRINES Oleh Weres Leon

  10. Silica Supported Ceria Nanoparticles: A Hybrid Nanostructure...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The surface chemical and vibrational spectroscopy analysis revealed cerium–silicate (Ce-O-Si) covalent bond linkage between silica and cerium oxide nanoparticles. The...

  11. Polymers Pushing Polymers: Polymer Mixtures in Thermodynamic Equilibrium with a Pore

    E-Print Network [OSTI]

    Podgornik, Rudolf

    Polymers Pushing Polymers: Polymer Mixtures in Thermodynamic Equilibrium with a Pore R. Podgornik, 1000 Ljubljana, Slovenia Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003, United States ABSTRACT: We investigate polymer partitioning from polymer

  12. POLYMER PROGRAM SEMINAR "Nanomanufacturing with Polymers"

    E-Print Network [OSTI]

    Alpay, S. Pamir

    POLYMER PROGRAM SEMINAR "Nanomanufacturing with Polymers" Prof. Joey Mead University Lowell has developed a suite of processes to enable the nanomanufacturing of polymer based products of properties (e.g. biocompatibility, polarity, and modulus). Polymer materials can be used as substrates

  13. Red-luminescent europium (III) doped silica nanoshells: synthesis,

    E-Print Network [OSTI]

    Kummel, Andrew C.

    Red-luminescent europium (III) doped silica nanoshells: synthesis, characterization(6), 066012 (June 2011) Red-luminescent europium (III) doped silica nanoshells: synthesis, characterization (SPIE). [DOI: 10.1117/1.3593003] Keywords: europium; silica; luminescent; nanoshells; endocytosis. Paper

  14. Role of Polymer Segment?Particle Surface Interactions in Controlling Nanoparticle Dispersions in Concentrated Polymer Solutions

    SciTech Connect (OSTI)

    Kim, So Youn; Zukoski, Charles F. (UIUC)

    2014-09-24T23:59:59.000Z

    The microstructure of particles suspended in concentrated polymer solutions is examined with small-angle X-ray scattering and small-angle neutron scattering. Of interest are changes to long wavelength particle density fluctuations in ternary mixtures of silica nanoparticles suspended in concentrated solutions of poly(ethylene glycol). The results are understood in terms of application of the pseudo-two-component polymer reference interaction site model (PRISM) theory modified to account for solvent addition via effective contact strength of interfacial attraction, {var_epsilon}{sub pc}, in an implicit manner. The combined experimental-theoretical study emphasizes the complex interactions between solvent, polymer, and particle surface that control particle miscibility but also demonstrate that these factors can all be understood in terms of variations of {var_epsilon}{sub pc}.

  15. Epoxidised Natural Rubber Based Composite Polymer Electrolyte Systems For Use In Electrochemical Device Applications

    SciTech Connect (OSTI)

    Idris, Razali; Tasnim, Anis; Mahbor, Kamisah Mohamad [Advanced Materials Research Centre, Lot 34 Kulim Hi-Tech Park, 09000 Kulim, Kedah (Malaysia); Hakim, Mas Rosemal [School of Chemical Sciences, University Sciences of Malaysia, 11800 USM, Minden, P. Pinang (Malaysia); Mohd, Dahlan Hj.; Ghazali, Zulkafli [Radiation Processing Technology Division, Malaysian Nuclear Agency, Dengkil, 43000 Kajang, Selangor (Malaysia)

    2009-09-14T23:59:59.000Z

    Composite polymer electrolyte (CPE) comprising epoxy-fimctionalized rubber (ENR), HDDA monomer, mixed plasticizer-propylene carbonate/ethylene carbonate, silica filler and lithium bis(trifluoromethanesulfonylimide), Li[(CF{sub 3}SO{sub 2}){sub 2}N]have been prepared using photo-induced polymerization by UV irradiation technique. The irradiated samples of filled and non-filled silica of composites electrolytes have formed dry solid-flexible and transparent films in the self-constructed Teflon mould. Thermal behaviors, FTIR, morphology and ionic conductivity were performed on such ENR based PE polymer composites having varied compositions. The thermal stability has improved slightly in the temperature range 120-200 deg. C with optimized composition. FTIR measurements data revealed that the interaction of lithium with the epoxy groups of the un-bonded electrons within polymer occurred. The results suggest that the variation of conductivity with temperature indicates that the silica filled composite has achieved optimal ionic conductivity 10{sup -4} S cm{sup -1} and retained high percent of plasticizer. The ionic conductivity behavior of the silica-filled ENR based composite polymer electrolyte is consistent at elevated temperature compared to non-filled CPE system. This finding opens a new pathway for further investigation to diffusion of ions in the complex polymer electrolyte systems.

  16. Synthesis and properties of Chitosan-silica hybrid aerogels

    SciTech Connect (OSTI)

    Ayers, Michael R.; Hunt, Arlon J.

    2001-06-01T23:59:59.000Z

    Chitosan, a polymer that is soluble in dilute aqueous acid, is derived from chitin, a natural polyglucosamide. Aquagels where the solid phase consists of both chitosan and silica can be easily prepared by using an acidic solution of chitosan to catalyze the hydrolysis and condensation of tetraethylorthosilicate. Gels with chitosan/TEOS mass ratios of 0.1-1.1 have been prepared by this method. Standard drying processes using CO{sub 2} give the corresponding aerogels. The amount of chitosan in the gel plays a role in the shrinkage of the aerogel during drying. Gels with the lowest chitosan/silica ratios show the most linear shrinkage, up to 24%, while those with the highest ratios show only a 7% linear shrinkage. Pyrolysis at 700 C under nitrogen produces a darkened aerogel due to the thermal decomposition of the chitosan, however, the aerogel retains its monolithic form. The pyrolyzed aerogels absorb slightly more infrared radiation in the 2-5 {micro}m region than the original aerogels. B.E.T. surface areas of these aerogels range from 470-750 m{sup 2}/g. Biocompatibility screening of this material shows a very high value for hemolysis, but a low value for cytotoxicity.

  17. Synthesis of supported carbon nanotubes in mineralized silica...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    supported carbon nanotubes in mineralized silica-wood composites. Synthesis of supported carbon nanotubes in mineralized silica-wood composites. Abstract: Multiwall carbon...

  18. Functionalized Nanoporous Silica for Removal of Heavy Metals...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Nanoporous Silica for Removal of Heavy Metals from Biological Systems; Adsorption and Application. Functionalized Nanoporous Silica for Removal of Heavy Metals from Biological...

  19. Templating Mesoporous Hierarchies in Silica Thin Films Using...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Templating Mesoporous Hierarchies in Silica Thin Films Using the Thermal Degradation of Cellulose Nitrate. Templating Mesoporous Hierarchies in Silica Thin Films Using the Thermal...

  20. Synthesis and properties of Chitosan-silica hybrid aerogels

    E-Print Network [OSTI]

    Ayers, Michael R.; Hunt, Arlon J.

    2001-01-01T23:59:59.000Z

    chitosan-silica composite aerogels can be easily synthesizedphysical properties of these aerogels. These materials may1. Top: Chitosan-silica aerogel (sample 4), Bottom: Same

  1. Silica Deposition | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries Pvt LtdShawangunk, New York:SiG Solar GmbH Jump to:SierraMountain,SilentSilica

  2. Gold Nanoparticle Silica Nanopeapods Vu Thanh Cong,,

    E-Print Network [OSTI]

    Kim, Sehun

    Gold Nanoparticle Silica Nanopeapods Vu Thanh Cong,, Erdene-Ochir Ganbold,§ Joyanta K. Saha gold nanoparticle (AuNP) silica nanotube peapod (SNTP) was fabricated by self-assembly. The geometrical-dependent surface-enhanced Raman scattering (SERS) spectra of bifunctional aromatic linker p-mercaptobenzoic acid (p-MBA)-coated

  3. UV-nanoimprint lithography and large area roll-to-roll texturization with hyperbranched polymer nanocomposites for light-trapping applications$

    E-Print Network [OSTI]

    UV-nanoimprint lithography and large area roll-to-roll texturization with hyperbranched polymer nanoimprint lithography Light-trapping Roll-to-roll Amorphous silicon a b s t r a c t Light-trapping textures were produced in hyperbranched polymer (HBP) silica nanocomposites using a UV-nanoimprint lithography

  4. Conductive Polymers

    SciTech Connect (OSTI)

    Bohnert, G.W.

    2002-11-22T23:59:59.000Z

    Electroluminescent devices such as light-emitting diodes (LED) and high-energy density batteries. These new polymers offer cost savings, weight reduction, ease of processing, and inherent rugged design compared to conventional semiconductor materials. The photovoltaic industry has grown more than 30% during the past three years. Lightweight, flexible solar modules are being used by the U.S. Army and Marine Corps for field power units. LEDs historically used for indicator lights are now being investigated for general lighting to replace fluorescent and incandescent lights. These so-called solid-state lights are becoming more prevalent across the country since they produce efficient lighting with little heat generation. Conductive polymers are being sought for battery development as well. Considerable weight savings over conventional cathode materials used in secondary storage batteries make portable devices easier to carry and electric cars more efficient and nimble. Secondary battery sales represent an $8 billion industry annually. The purpose of the project was to synthesize and characterize conductive polymers. TRACE Photonics Inc. has researched critical issues which affect conductivity. Much of their work has focused on production of substituted poly(phenylenevinylene) compounds. These compounds exhibit greater solubility over the parent polyphenylenevinylene, making them easier to process. Alkoxy substituted groups evaluated during this study included: methoxy, propoxy, and heptyloxy. Synthesis routes for production of alkoxy-substituted poly phenylenevinylene were developed. Considerable emphasis was placed on final product yield and purity.

  5. Sample Desorption/Onization From Mesoporous Silica

    DOE Patents [OSTI]

    Iyer, Srinivas (Los Alamos, NM); Dattelbaum, Andrew M. (Los Alamos, NM)

    2005-10-25T23:59:59.000Z

    Mesoporous silica is shown to be a sample holder for laser desorption/ionization of mass spectrometry. Supported mesoporous silica was prepared by coating an ethanolic silicate solution having a removable surfactant onto a substrate to produce a self-assembled, ordered, nanocomposite silica thin film. The surfactant was chosen to provide a desired pore size between about 1 nanometer diameter and 50 nanometers diameter. Removal of the surfactant resulted in a mesoporous silica thin film on the substrate. Samples having a molecular weight below 1000, such as C.sub.60 and tryptophan, were adsorbed onto and into the mesoporous silica thin film sample holder and analyzed using laser desorption/ionization mass spectrometry.

  6. Phase behavior of polymers and monomers 

    E-Print Network [OSTI]

    Purifoy, Jonathan Patrick

    1998-01-01T23:59:59.000Z

    This study seeks to determine the effects of polymer structure and composition on the cloud-point of polymer-solvent mixtures. Mixtures of ethylene gas with poly(ethylene-co-methyl methacrylate), poly(ethylene-co-methacrylic acid) and poly...

  7. Dielectric Actuation of Polymers

    E-Print Network [OSTI]

    Niu, Xiaofan

    2013-01-01T23:59:59.000Z

    strain in dielectric elastomers, Journal of Polymer SciencePart B: Polymer Physics. 49 (2011) 504–515. [25] X. Zhao, Z.Electroactive nanostructured polymers as tunable actuators,

  8. Fluid diversion and sweep improvement with chemical gels in oil recovery processes. [Four types of gels: resorcinol-formaldehyde; colloidal silica; Cr sup 3+ (chloride)-xanthan; and Cr sup 3+ (acetate)-polyacrylamide

    SciTech Connect (OSTI)

    Seright, R.S.; Martin, F.D.

    1992-09-01T23:59:59.000Z

    The objectives of this project were to identify the mechanisms by which gel treatments divert fluids in reservoirs and to establish where and how gel treatments are best applied. Several different types of gelants were examined, including polymer-based gelants, a monomer-based gelant, and a colloidal-silica gelant. This research was directed at gel applications in water injection wells, in production wells, and in high-pressure gas floods. The work examined how the flow properties of gels and gelling agents are influenced by permeability, lithology, and wettability. Other goals included determining the proper placement of gelants, the stability of in-place gels, and the types of gels required for the various oil recovery processes and for different scales of reservoir heterogeneity. During this three-year project, a number of theoretical analyses were performed to determine where gel treatments are expected to work best and where they are not expected to be effective. The most important, predictions from these analyses are presented. Undoubtedly, some of these predictions will be controversial. However, they do provide a starting point in establishing guidelines for the selection of field candidates for gel treatments. A logical next step is to seek field data that either confirm or contradict these predictions. The experimental work focused on four types of gels: (1) resorcinol-formaldehyde, (2) colloidal silica, (3) Cr{sup 3+}(chloride)-xanthan, and (4) Cr{sup 3+}(acetate)-polyacrylamide. All experiments were performed at 41{degrees}C.

  9. Dielectric Actuation of Polymers

    E-Print Network [OSTI]

    Niu, Xiaofan

    2013-01-01T23:59:59.000Z

    AgNW) polymer composite material that is conductive enoughAgNW/polymer composite was nominated as a highly conductive,

  10. Borrowing Nature's Polymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Borrowing Nature's Polymers 1663 Los Alamos science and technology magazine Latest Issue:January 2015 All Issues submit Borrowing Nature's Polymers Los Alamos scientists are...

  11. Silylation of low-density silica and bridged polysilsesquioxane aerogels

    SciTech Connect (OSTI)

    DeFriend, K. A. (Kimberly A.); Loy, D. A. (Douglas A.); Salazar, K. V. (Kenneth V.); Wilson, K. V. (Kennard V.)

    2004-01-01T23:59:59.000Z

    Silica and bridged polysilsesquioxane aerogels are low-density materials that are attractive for applications such as thermal insulation, porous separation media or catalyst supports, adsorbents, and cometary dust capture agents. However, aerogels are notoriously weak and brittle making it difficult to handle and machine monoliths into desired forms. This complication prevents the development of many applications that would otherwise benefit from the use of the low-density materials. Here, we will describe our efforts to chemically modify and mechanically enhance silica-based aerogels using chemical vapor techniques without sacrificing their characteristic low densities. Monolithic silica and organic-bridged polysilsesquioxane aerogels were prepared by sol-gel polymerization of the respective methoxysilane monomers followed by supercritical carbon dioxide drying of the gels. Then the gels were reactively modified with silylating agents to demonstrate the viability of CVD modification of aerogels, and to determine the effects of silylation of surface silanols on the morphology, surface area, and mechanical properties of the resulting aerogels.

  12. Highly efficient carbon dioxide capture with a porous organic polymer impregnated with

    E-Print Network [OSTI]

    Paik Suh, Myunghyun

    Highly efficient carbon dioxide capture with a porous organic polymer impregnated environmental crises such as global warming and ocean acidication, efficient carbon dioxide (CO2) capture As CO2 capture mate- rials, numerous solid adsorbents such as silica5 and carbon materials,6 metal

  13. Monodisperse metal nanoparticle catalysts on silica mesoporous supports: synthesis, characterizations, and catalytic reactions

    SciTech Connect (OSTI)

    Somorjai, G.A.

    2009-09-14T23:59:59.000Z

    The design of high performance catalyst achieving near 100% product selectivity at maximum activity is one of the most important goals in the modern catalytic science research. To this end, the preparation of model catalysts whose catalytic performances can be predicted in a systematic and rational manner is of significant importance, which thereby allows understanding of the molecular ingredients affecting the catalytic performances. We have designed novel 3-dimensional (3D) high surface area model catalysts by the integration of colloidal metal nanoparticles and mesoporous silica supports. Monodisperse colloidal metal NPs with controllable size and shape were synthesized using dendrimers, polymers, or surfactants as the surface stabilizers. The size of Pt, and Rh nanoparticles can be varied from sub 1 nm to 15 nm, while the shape of Pt can be controlled to cube, cuboctahedron, and octahedron. The 3D model catalysts were generated by the incorporation of metal nanoparticles into the pores of mesoporous silica supports via two methods: capillary inclusion (CI) and nanoparticle encapsulation (NE). The former method relies on the sonication-induced inclusion of metal nanoparticles into the pores of mesoporous silica, whereas the latter is performed by the encapsulation of metal nanoparticles during the hydrothermal synthesis of mesoporous silica. The 3D model catalysts were comprehensively characterized by a variety of physical and chemical methods. These catalysts were found to show structure sensitivity in hydrocarbon conversion reactions. The Pt NPs supported on mesoporous SBA-15 silica (Pt/SBA-15) displayed significant particle size sensitivity in ethane hydrogenolysis over the size range of 1-7 nm. The Pt/SBA-15 catalysts also exhibited particle size dependent product selectivity in cyclohexene hydrogenation, crotonaldehyde hydrogenation, and pyrrole hydrogenation. The Rh loaded SBA-15 silica catalyst showed structure sensitivity in CO oxidation reaction. In addition, Pt-mesoporous silica core-shell structured NPs (Pt{at}mSiO{sub 2}) were prepared, where the individual Pt NP is encapsulated by the mesoporous silica layer. The Pt{at}mSiO{sub 2} catalysts showed promising catalytic activity in high temperature CO oxidation. The design of catalytic structures with tunable parameters by rational synthetic methods presents a major advance in the field of catalyst synthesis, which would lead to uncover the structure-function relationships in heterogeneous catalytic reactions.

  14. Hollow silica and silica-boron nano/microparticles for contrast-enhanced ultrasound to detect small tumors

    E-Print Network [OSTI]

    Kummel, Andrew C.

    Hollow silica and silica-boron nano/microparticles for contrast-enhanced ultrasound to detect small Accepted 18 March 2012 Available online 11 April 2012 Keywords: Ultrasound Nano Silica Shells Imaging detection, gas filled hollow boron-doped silica particles have been developed, which can be used

  15. Polymers with increased order

    DOE Patents [OSTI]

    Sawan, Samuel P. (Tyngsborough, MA); Talhi, Abdelhafid (Rochester, MI); Taylor, Craig M. (Jemez Springs, NM)

    1998-08-25T23:59:59.000Z

    The invention features polymers with increased order, and methods of making them featuring a dense gas.

  16. CHEMISTRY OF SILICA IN CERRO PRIETO BRINES

    E-Print Network [OSTI]

    Weres, O.

    2012-01-01T23:59:59.000Z

    chemistry of silica in Cerro Prieto brine may profitably be14 mg·l-1 AND SYNTHFTIC CERRO PRIETO BRINES High Ca We112Q.by the CFE Laboratory at Cerro Prieto and kindly provided to

  17. LIGHT SCATTERING STUDIES OF SILICA AEROGELS

    E-Print Network [OSTI]

    Hunt, A.J.

    2010-01-01T23:59:59.000Z

    S.S. , "Coherent Expanded Aerogels," J. of Phys. Chern.Production of Silica Aerogel," Physica Scripta 23, Nicolaon,S.J. , "Preparation des aerogels de silice a partir

  18. CX-005801: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    Determination CX-005801: Categorical Exclusion Determination Polymer Synthesis, Corrosion, and Electrochemical Tests in Lab D-0115 CX(s) Applied: B3.6 Date: 03312011...

  19. Multimodality Imaging with Silica-Based Targeted Nanoparticle Platforms

    SciTech Connect (OSTI)

    Jason S. Lewis

    2012-04-09T23:59:59.000Z

    Objectives: To synthesize and characterize a C-Dot silica-based nanoparticle containing 'clickable' groups for the subsequent attachment of targeting moieties (e.g., peptides) and multiple contrast agents (e.g., radionuclides with high specific activity) [1,2]. These new constructs will be tested in suitable tumor models in vitro and in vivo to ensure maintenance of target-specificity and high specific activity. Methods: Cy5 dye molecules are cross-linked to a silica precursor which is reacted to form a dye-rich core particle. This core is then encapsulated in a layer of pure silica to create the core-shell C-Dot (Figure 1) [2]. A 'click' chemistry approach has been used to functionalize the silica shell with radionuclides conferring high contrast and specific activity (e.g. 64Cu and 89Zr) and peptides for tumor targeting (e.g. cRGD and octreotate) [3]. Based on the selective Diels-Alder reaction between tetrazine and norbornene, the reaction is bioorthogonal, highyielding, rapid, and water-compatible. This radiolabeling approach has already been employed successfully with both short peptides (e.g. octreotate) and antibodies (e.g. trastuzumab) as model systems for the ultimate labeling of the nanoparticles [1]. Results: PEGylated C-Dots with a Cy5 core and labeled with tetrazine have been synthesized (d = 55 nm, zeta potential = -3 mV) reliably and reproducibly and have been shown to be stable under physiological conditions for up to 1 month. Characterization of the nanoparticles revealed that the immobilized Cy5 dye within the C-Dots exhibited fluorescence intensities over twice that of the fluorophore alone. The nanoparticles were successfully radiolabeled with Cu-64. Efforts toward the conjugation of targeting peptides (e.g. cRGD) are underway. In vitro stability, specificity, and uptake studies as well as in vivo imaging and biodistribution investigations will be presented. Conclusions: C-Dot silica-based nanoparticles offer a robust, versatile, and multi-functional platform to enhance in vivo detection sensitivity and non-invasively assay receptor expression/status of tumor cellular targets, including those of low abundance, using nuclear-NIR fluorescence imaging approaches [2]. Improvements in molecular diagnostics, refined by the availability of nanotechnology platforms, will be a key determinant in driving early-stage disease detection and prevention, ultimately leading to decreases in mortality.

  20. The Management of Silica in Los Alamos National Laboratory Tap Water - A Study of Silica Solubility

    SciTech Connect (OSTI)

    Wohlberg, C.; Worland, V.P.; Kozubal, M.A.; Erickson, G.F.; Jacobson, H.M.; McCarthy, K.T.

    1999-07-01T23:59:59.000Z

    Well water at Los Alamos National Laboratory (LANL) has a silica (SiO{sub 2}) content of 60 to 100 mg/L, with 4 mg/L of magnesium, 13 mg/L calcium and lesser concentrations of other ions. On evaporation in cooling towers, when the silica concentration reaches 150 to 220 mg/L, silica deposits on heat transfer surfaces. When the high silica well water is used in the reprocessing of plutonium, silica remains in solution at the end of the process and creates a problem of removal from the effluent prior to discharge or evaporation. The work described in this Report is divided into two major parts. The first part describes the behavior of silica when the water is evaporated at various conditions of pH and in the presence of different classes of anions: inorganic and organic. In the second part of this work it was found that precipitation (floccing) of silica was a function of solution pH and mole ratio of metal to silica.

  1. The strict-weak lattice polymer

    E-Print Network [OSTI]

    Ivan Corwin; Timo Seppäläinen; Hao Shen

    2015-07-06T23:59:59.000Z

    We introduce the strict-weak polymer model, and show the KPZ universality of the free energy fluctuation of this model for a certain range of parameters. Our proof relies on the observation that the discrete time geometric q-TASEP model, studied earlier by A. Borodin and I. Corwin, scales to this polymer model in the limit q->1. This allows us to exploit the exact results for geometric q-TASEP to derive a Fredholm determinant formula for the strict-weak polymer, and in turn perform rigorous asymptotic analysis to show KPZ scaling and GUE Tracy-Widom limit for the free energy fluctuations. We also derive moments formulae for the polymer partition function directly by Bethe ansatz, and identify the limit of the free energy using a stationary version of the polymer model.

  2. The strict-weak lattice polymer

    E-Print Network [OSTI]

    Ivan Corwin; Timo Seppäläinen; Hao Shen

    2014-09-05T23:59:59.000Z

    We introduce the strict-weak polymer model, and show the KPZ universality of the free energy fluctuation of this model for a certain range of parameters. Our proof relies on the observation that the discrete time geometric q-TASEP model, studied earlier by A. Borodin and I. Corwin, scales to this polymer model in the limit q->1. This allows us to exploit the exact results for geometric q-TASEP to derive a Fredholm determinant formula for the strict-weak polymer, and in turn perform rigorous asymptotic analysis to show KPZ scaling and GUE Tracy-Widom limit for the free energy fluctuations. We also derive moments formulae for the polymer partition function directly by Bethe ansatz, and identify the limit of the free energy using a stationary version of the polymer model.

  3. Treatment of domestic wastewater for reuse with activated silica and magnesia 

    E-Print Network [OSTI]

    Lindner, John Howard

    1985-01-01T23:59:59.000Z

    and lime are effective at removing these components' The effectiveness of these coagulants was determined by running a series of jar tests on treated domestic wastewater over a range of pH values. Samples were taken of each coagulant dose added and a... of activated silica in combination with 60 mg/1 alum. Both series 20 were run at pH values of 4, 5, 6, 7, 8 and 9. A third series of jar tests were conducted with low doses of activated silica and sufficient lime to obtain a pH of 9, 10 and 11...

  4. E-Print Network 3.0 - alumina silica-alumina etude Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    14 (2004) 681686 PII: S0960-1317(04)71691-5 Summary: for silica, alumina, and titania aerogels. Silica and alumina aerogel cantilevers are fabricated on the basis... Silica Silica...

  5. Direct encapsulation of water-soluble drug into silica microcapsules for sustained release applications

    SciTech Connect (OSTI)

    Wang Jiexin; Wang Zhihui [Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Chen Jianfeng [Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China)], E-mail: chenjf@mail.buct.edu.cn; Yun, Jimmy [Nanomaterials Technology Pte. Ltd., 28 Ayer Rajah Crescent 03-03, Singapore 139959 (Singapore)

    2008-12-01T23:59:59.000Z

    Direct encapsulation of water-soluble drug into silica microcapsules was facilely achieved by a sol-gel process of tetraethoxysilane (TEOS) in W/O emulsion with hydrochloric acid (HCl) aqueous solution containing Tween 80 and drug as well as cyclohexane solution containing Span 80. Two water-soluble drugs of gentamicin sulphate (GS) and salbutamol sulphate (SS) were chosen as model drugs. The characterization of drug encapsulated silica microcapsules by scanning electronic microscopy (SEM), FTIR, thermogravimetry (TG) and N{sub 2} adsorption-desorption analyses indicated that drug was successfully entrapped into silica microcapsules. The as-prepared silica microcapsules were uniform spherical particles with hollow structure, good dispersion and a size of 5-10 {mu}m, and had a specific surface area of about 306 m{sup 2}/g. UV-vis and thermogravimetry (TG) analyses were performed to determine the amount of drug encapsulated in the microcapsules. The BJH pore size distribution (PSD) of silica microcapsules before and after removing drug was examined. In vitro release behavior of drug in simulated body fluid (SBF) revealed that such system exhibited excellent sustained release properties.

  6. Synchrotron Radiation in Polymer Science

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synchrotron Radiation in Polymer Science Synchrotron Radiation in Polymer Science March 30-April 2, 2012; San Francisco...

  7. Stiff Quantum Polymers

    E-Print Network [OSTI]

    H. Kleinert

    2007-05-01T23:59:59.000Z

    At ultralow temperatures, polymers exhibit quantum behavior, which is calculated here for the moments and of the end-to-end distribution in the large-stiffness regime. The result should be measurable for polymers in wide optical traps.

  8. High resolution patterning of silica aerogels

    SciTech Connect (OSTI)

    Bertino, M.F.; Hund, J.F.; Sosa, J.; Zhang, G.; Sotiriou-Leventis, C.; Leventis, N.; Tokuhiro, A.T.; Terry, J. (UMR-MUST); (IIT)

    2008-10-30T23:59:59.000Z

    Three-dimensional metallic structures are fabricated with high spatial resolution in silica aerogels. In our method, silica hydrogels are prepared with a standard base-catalyzed route, and exchanged with an aqueous solution typically containing Ag{sup +} ions (1 M) and 2-propanol (0.2 M). The metal ions are reduced photolytically with a table-top ultraviolet lamp, or radiolytically, with a focused X-ray beam. We fabricated dots and lines as small as 30 x 70 {micro}m, protruding for several mm into the bulk of the materials. The hydrogels are eventually supercritically dried to yield aerogels, without any measurable change in the shape and spatial resolution of the lithographed structures. Transmission electron microscopy shows that illuminated regions are composed by Ag clusters with a size of several {micro}m, separated by thin layers of silica.

  9. Insulating polymer concrete

    DOE Patents [OSTI]

    Schorr, H. Peter (Douglaston, NY); Fontana, Jack J. (Shirley, NY); Steinberg, Meyer (Melville, NY)

    1987-01-01T23:59:59.000Z

    A lightweight insulating polymer concrete formed from a lightweight closed cell aggregate and a water resistance polymeric binder.

  10. Measurement of muonium emission from silica aerogel

    E-Print Network [OSTI]

    P. Bakule; G. A. Beer; D. Contreras; M. Esashi; Y. Fujiwara; Y. Fukao; S. Hirota; H. Iinuma; K. Ishida; M. Iwasaki; T. Kakurai; S. Kanda; H. Kawai; N. Kawamura; G. M. Marshall; H. Masuda; Y. Matsuda; T. Mibe; Y. Miyake; S. Okada; K. Olchanski; A. Olin; H. Onishi; N. Saito; K. Shimomura; P. Strasser; M. Tabata; D. Tomono; K. Ueno; K. Yokoyama; S. Yoshida

    2013-06-17T23:59:59.000Z

    Emission of muonium ($\\mu^{+}e^{-}$) atoms from silica aerogel into vacuum was observed. Characteristics of muonium emission were established from silica aerogel samples with densities in the range from 29 mg cm$^{-3}$ to 178 mg cm$^{-3}$. Spectra of muonium decay times correlated with distances from the aerogel surfaces, which are sensitive to the speed distributions, follow general features expected from a diffusion process, while small deviations from a simple room-temperature thermal diffusion model are identified. The parameters of the diffusion process are deduced from the observed yields.

  11. Measurement of muonium emission from silica aerogel

    E-Print Network [OSTI]

    Bakule, P; Contreras, D; Esashi, M; Fujiwara, Y; Fukao, Y; Hirota, S; Iinuma, H; Ishida, K; Iwasaki, M; Kakurai, T; Kanda, S; Kawai, H; Kawamura, N; Marshall, G M; Masuda, H; Matsuda, Y; Mibe, T; Miyake, Y; Okada, S; Olchanski, K; Olin, A; Onishi, H; Saito, N; Shimomura, K; Strasser, P; Tabata, M; Tomono, D; Ueno, K; Yokoyama, K; Yoshida, S

    2013-01-01T23:59:59.000Z

    Emission of muonium ($\\mu^{+}e^{-}$) atoms from silica aerogel into vacuum was observed. Characteristics of muonium emission were established from silica aerogel samples with densities in the range from 29 mg cm$^{-3}$ to 178 mg cm$^{-3}$. Spectra of muonium decay times correlated with distances from the aerogel surfaces, which are sensitive to the speed distributions, follow general features expected from a diffusion process, while small deviations from a simple room-temperature thermal diffusion model are identified. The parameters of the diffusion process are deduced from the observed yields.

  12. Lithographically directed deposition of silica nanoparticles using spin coating

    E-Print Network [OSTI]

    New Mexico, University of

    Lithographically directed deposition of silica nanoparticles using spin coating Deying Xia and S. R-assembly by spin coating to control particle placement. Three sizes of silica nanoparticles (mean diameters: 78, 50, and 15 nm) were employed for spin-coating processes. Single linear silica particle chain patterns

  13. A threshold Cherenkov detector for K separation using silica aerogel

    E-Print Network [OSTI]

    Magiera, Andrzej

    A threshold Cherenkov detector for Kþ =pþ separation using silica aerogel R. Siudak a,b , A August 2008 Keywords: Threshold Cherenkov detector Silica aerogel Reaction pp ! Kþ ðLp� Kþ =pþ separation in the focal plane of a magnetic spectrograph. Silica aerogel with refractive index of n ¼ 1:05 is applied

  14. Nanoporous polymer electrolyte

    DOE Patents [OSTI]

    Elliott, Brian (Wheat Ridge, CO); Nguyen, Vinh (Wheat Ridge, CO)

    2012-04-24T23:59:59.000Z

    A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at 25.degree. C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

  15. Entropic Trapping of Particles at Polymer Surfaces and Interfaces

    E-Print Network [OSTI]

    Galen T. Pickett

    2015-05-22T23:59:59.000Z

    I consider the possibility that Gaussian random walk statistics are sufficient to trap nanoscopic additives at either a polymer interface or surface. When an additive particle goes to the free surface, two portions of the polymer surface energy behave quite differently. The purely enthalpic contribution increases the overall free energy when the additive protrudes above the level of the polymer matrix. The entropic part of the surface energy arising from constraints that segments near a surface can't cross it, is partly relaxed when the additive moves to the free surface. These two portions of the polymer surface energy determine the equilibrium wetting angle formed between the additive and the polymer matrix, the measurement of which in an experiment would allow an independent determination of each piece of the polymer surface energy.

  16. Effectiveness of cabs for dust and silica control on mobile mining equipment

    SciTech Connect (OSTI)

    Garcia, J.J.; Gresh, R.E.; Gareis, M.B.; Haney, R.A.

    1999-07-01T23:59:59.000Z

    The Mine Safety and Health Administration (MSHA) has conducted a study to evaluate the effectiveness of cabs for controlling silica dust exposure during operation of mobile mining equipment. This study focused on bulldozers, front-end loaders and haul trucks, was conducted at surface coal mining operations and underground metal and nonmetal mining operations. Each piece of equipment tested was equipped with a cab. The vehicles sampled were from a range of manufacturers having different types of filter media and air intake configurations. The purpose of this study was to determine the reduction of dust and silica exposure that could be achieved through the use of a well-maintained cab. For each piece of equipment, dust and silica concentrations inside and outside the cab were determined and compared. In some cases, filtration efficiencies could be calculated. A properly designed environmental cab is sealed, has an intake air filtration system, and a heating and cooling system. Cabs should have good seals around the doors and windows. Factors such as cab pressurization filtration systems, filter media, and maintenance practices were also examined. In some cases, dust and silica reduction of 90 to 95% were observed.

  17. Adsorption of polymer chains at penetrable interfaces

    SciTech Connect (OSTI)

    Gerasimchuk, I. V., E-mail: igor.gera@gmail.com [National Academy of Sciences of Ukraine and Ministry of Education and Science of Ukraine, Institute of Magnetism (Ukraine); Sommer, J.-U. [Leibniz Institute of Polymer Research Dresden e.V. (Germany); Gerasimchuk, V. S. [National Technical University of Ukraine 'Kyiv Polytechnic Institute' (Ukraine)

    2011-03-15T23:59:59.000Z

    We investigate the problem of adsorption (localization) of polymer chains in the system of two penetrable interfaces within the mean-field approximation. The saturation of the polymer system in the limit case of zero bulk concentration is studied. We find the exact solution of this mean-field polymer adsorption problem that opens the possibility to treat various localization problems for polymer chains in such environments using appropriate boundary conditions. The exact solution is controlled by a single scaling variable that describes the coupling between the interfaces due to the polymer chains. We obtain a nonmonotonic behavior of the amount of adsorbed polymers as a function of the distance between the interfaces. This leads to a high-energy and a low-energy phase for the double layer with respect to the amount of polymers localized. At the saturation point, we find the total energy of the system and determine the force acting between the interfaces to be strictly attractive and to monotonically decay to zero when the interface distance increases.

  18. Chemistry of Silica in Cerro Prieto Brines

    E-Print Network [OSTI]

    Weres, Oleh

    2012-01-01T23:59:59.000Z

    1975). When operated without sludge r e c i r c u l a t i ot o c o l l o i d a l silica. sludge accumulation there. thel a t i o n of part of the sludge coming out of The l a r g

  19. Chemistry of Silica in Cerro Prieto Brines

    E-Print Network [OSTI]

    Weres, O.

    2010-01-01T23:59:59.000Z

    1975). When operated without sludge r e c i r c u l a t i ot o c o l l o i d a l silica. sludge accumulation there. thel a t i o n of part of the sludge coming out of The l a r g

  20. Catalysis over activated high silica zeolites

    SciTech Connect (OSTI)

    Chang, C. D.; Miale, N.

    1985-07-23T23:59:59.000Z

    A process is provided for conducting organic compound conversion over a catalyst composition comprising a crystalline zeolite having a high initial silica-to-alumina mole ratio, said zeolite being prepared by calcining the zeolite, contacting said calcined zeolite with solid aluminum fluoride, and coverting said aluminum fluoride contacted material to hydrogen form.

  1. Dissolution retardation of solid silica during glass batch-melting

    SciTech Connect (OSTI)

    Hrma, Pavel R.; Marcial, Jose

    2011-07-15T23:59:59.000Z

    During glass-batch melting, solid silica (quartz) usually dissolves last. A retardation function was defined as a measure of the progressive inhibition of silica dissolution that occurs during batch melting. This function is based on the comparison of the measured rate of dissolution of silica particles with the hypothetical diffusion-controlled volume flux from regularly distributed particles with uniform concentration layers around them. The severe inhibition of silica dissolution has been attributed to the irregular spatial distribution of silica particles that is associated with the formation of nearly saturated melt at a portion of their surfaces. Irregular shapes and unequal sizes of particles also contribute to their extended lifetime.

  2. Mechanics of amorphous polymers and polymer gels

    E-Print Network [OSTI]

    Chester, Shawn Alexander

    2011-01-01T23:59:59.000Z

    Many applications of amorphous polymers require a thermo-mechanically coupled large-deformation elasto-viscoplasticity theory which models the strain rate and temperature dependent response of amorphous polymeric materials ...

  3. "Wet-to-Dry" Conformational Transition of Polymer Layers Grafted to Nanoparticles in Nanocomposite

    E-Print Network [OSTI]

    Chloé Chevigny; Jacques Jestin; Didier Gigmes; Ralph Schweins; Emanuela Null Di Cola; Florent Dalmas; Denis Bertin; François Boué

    2010-05-10T23:59:59.000Z

    The present communication reports the first direct measurement of the conformation of a polymer corona grafted around silica nano-particles dispersed inside a nanocomposite, a matrix of the same polymer. This measurement constitutes an experimental breakthrough based on a refined combination of chemical synthesis, which permits to match the contribution of the neutron silica signal inside the composite, and the use of complementary scattering methods SANS and SAXS to extract the grafted polymer layer form factor from the inter-particles silica structure factor. The modelization of the signal of the grafted polymer on nanoparticles inside the matrix and the direct comparison with the form factor of the same particles in solution show a clear-cut change of the polymer conformation from bulk to the nanocomposite: a transition from a stretched and swollen form in solution to a Gaussian conformation in the matrix followed with a compression of a factor two of the grafted corona. In the probed range, increasing the interactions between the grafted particles (by increasing the particle volume fraction) or between the grafted and the free matrix chains (decreasing the grafted-free chain length ratio) does not influence the amplitude of the grafted brush compression. This is the first direct observation of the wet-to-dry conformational transition theoretically expected to minimize the free energy of swelling of grafted chains in interaction with free matrix chains, illustrating the competition between the mixing entropy of grafted and free chains, and the elastic deformation of the grafted chains. In addition to the experimental validation of the theoretical prediction, this result constitutes a new insight for the nderstanding of the general problem of dispersion of nanoparticles inside a polymer matrix for the design of new nanocomposites materials.

  4. CX-010528: Categorical Exclusion Determination | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Exclusion Determination Durability Investigation for Quarternary Phosphonium-based Polymer Hydroxide Exchange Membranes CX(s) Applied: B3.6 Date: 09182012 Location(s):...

  5. Tunneling of Polymer Particles

    E-Print Network [OSTI]

    A. Martín-Ruiz; E. Chan-López; A. Carbajal-Domínguez; J. Bernal

    2014-08-28T23:59:59.000Z

    In this paper we study the tunneling using a background independent (polymer) quantization scheme. We show that at low energies, for the tunneling through a single potential barrier, the polymer transmission coefficient and the polymer tunneling time converge to its quantum-mechanical counterparts in a clear fashion. As the energy approaches the maximum these polymer quantities abruptly decrease to zero. We use the transfer matrix method to study the tunneling through a series of identical potential barriers. We obtain that the transmission coefficients (polymer and quantum-mechanical) behave qualitatively in a similar manner, as expected. Finally we show that the polymer tunneling time exhibits anomalous peaks compared with the standard result. Numerical results are also presented.

  6. Nano-Structured Mesoporous Silica Wires with Intra-Wire Lamellae via Evaporation-Induced Self-Assembly in Space-Confined Channels

    SciTech Connect (OSTI)

    Hu, Michael Z. [ORNL; Shi, Donglu [University of Cincinnati; Blom, Douglas Allen [ORNL

    2014-01-01T23:59:59.000Z

    Evaporation-induced self-assembly (EISA) of silica sol-gel ethanol-water solution mixtures with block-copolymer were studied inside uniform micro/nano channels. Nano-structured mesoporous silica wires, with various intra-wire self-assembly structures including lamellae, were prepared via EISA process but in space-confined channels with the diameter ranging from 50 nm to 200 nm. Membranes made of anodized aluminum oxide (AAO) and track-etched polycarbonate (EPC) were utilized as the arrays of space-confined channels (i.e., 50, 100, and 200-nm EPC and 200-nm AAO) for infiltration and drying of mixture solutions; these substrate membranes were submerged in mixture solutions consisting of a silica precursor, a structure-directing agent, ethanol, and water. After the substrate channels were filled with the solution under vacuum impregnation, the membrane was removed from the solution and dried in air. The silica precursor used was tetra-ethyl othosilicate (TEOS), and the structure-directing agent employed was triblock copolymer Pluronic-123 (P123). It was found that the formation of the mesoporous nanostructures in silica wires within uniform channels were significantly affected by the synthesis conditions including (1) pre-assemble TEOS aging time, (2) the evaporation rate during the vacuum impregnation, and (3) the air-dry temperature. The obtained intra-wire structures, including 2D-hexagonal rods and lamellae, were studied by scanning transmission electron microscopy (STEM). A steric hindrance effect seems to explain well the observed polymer-silica mesophase formation tailored by TEOS aging time. The evaporation effect, air-drying effect, and AAO-vs-EPC substrate effect on the mesoporous structure of the formed silica wires were also presented and discussed.

  7. Carbon nanomaterials in silica aerogel matrices

    SciTech Connect (OSTI)

    Hamilton, Christopher E [Los Alamos National Laboratory; Chavez, Manuel E [Los Alamos National Laboratory; Duque, Juan G [Los Alamos National Laboratory; Gupta, Gautam [Los Alamos National Laboratory; Doorn, Stephen K [Los Alamos National Laboratory; Dattelbaum, Andrew M [Los Alamos National Laboratory; Obrey, Kimberly A D [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    Silica aerogels are ultra low-density, high surface area materials that are extremely good thermal insulators and have numerous technical applications. However, their mechanical properties are not ideal, as they are brittle and prone to shattering. Conversely, single-walled carbon nanotubes (SWCNTs) and graphene-based materials, such as graphene oxide, have extremely high tensile strength and possess novel electronic properties. By introducing SWCNTs or graphene-based materials into aerogel matrices, it is possible to produce composites with the desirable properties of both constituents. We have successfully dispersed SWCNTs and graphene-based materials into silica gels. Subsequent supercritical drying results in monolithic low-density composites having improved mechanical properties. These nanocomposite aerogels have great potential for use in a wide range of applications.

  8. Light-scattering studies of silica aerogels

    SciTech Connect (OSTI)

    Hunt, A.J.

    1983-02-01T23:59:59.000Z

    Due to its combination of transparency and low thermal conductivity, aerogel holds considerable promise for use as insulating window materials for residential and commercial applications. This paper reports on the preliminary investigation of the optical and scattering properties of silica aerogels. It briefly describes the properties of aerogels important for window glazing applications. The optical properties are then described, followed by a discussion of the scattering measurements and their interpretation.

  9. Recent progress in silica aerogel Cherenkov radiator

    E-Print Network [OSTI]

    Makoto Tabata; Ichiro Adachi; Hideyuki Kawai; Masato Kubo; Takeshi Sato

    2012-03-19T23:59:59.000Z

    In this paper, we present recent progress in the development of hydrophobic silica aerogel as a Cherenkov radiator. In addition to the conventional method, the recently developed pin-drying method for producing high-refractive-index aerogels with high transparency was studied in detail. Optical qualities and large tile handling for crack-free aerogels were investigated. Sufficient photons were detected from high-performance aerogels in a beam test.

  10. Recent progress in silica aerogel Cherenkov radiator

    E-Print Network [OSTI]

    Tabata, Makoto; Kawai, Hideyuki; Kubo, Masato; Sato, Takeshi

    2012-01-01T23:59:59.000Z

    In this paper, we present recent progress in the development of hydrophobic silica aerogel as a Cherenkov radiator. In addition to the conventional method, the recently developed pin-drying method for producing high-refractive-index aerogels with high transparency was studied in detail. Optical qualities and large tile handling for crack-free aerogels were investigated. Sufficient photons were detected from high-performance aerogels in a beam test.

  11. Adsorption of Ruthenium and Iron Metallocenes on Silica: A Solid-State NMR Study

    E-Print Network [OSTI]

    Bluemel, Janet

    Adsorption of Ruthenium and Iron Metallocenes on Silica: A Solid- State NMR Study Kyle J. Cluff on silica surfaces by grinding the polycrystalline materials with silica. The adsorption process proceeds dry silica surface, wet and TMS- capped silica have been used as supports. The adsorption leads

  12. Shapes of Knotted Cyclic Polymers Eric J. Rawdon, University of St. Thomas, Saint Paul, MN, USA

    E-Print Network [OSTI]

    Bigelow, Stephen

    Shapes of Knotted Cyclic Polymers Eric J. Rawdon, University of St. Thomas, Saint Paul, MN, USA, USA Momentary configurations of long polymers at thermal equilibrium usually deviate from spherical of asphericity (or prolateness) that describe these momentary ellipsoidal shapes of a polymer are determined

  13. Semiflexible polymer solutions. I. Phase behavior and single-chain statistics

    E-Print Network [OSTI]

    Straight, Aaron

    Semiflexible polymer solutions. I. Phase behavior and single-chain statistics Andrew J. Spakowitz and single-chain statistics of wormlike polymer solutions with Maier­Saupe-type interactions using self; the presence of hairpins, though crucial for determining the dimensions of the polymer, has insignificant

  14. Experimental stress–strain analysis of tapered silica optical fibers with nanofiber waist

    SciTech Connect (OSTI)

    Holleis, S.; Hoinkes, T.; Wuttke, C.; Schneeweiss, P.; Rauschenbeutel, A. [Vienna Center for Quantum Science and Technology, TU Wien—Atominstitut, Stadionallee 2, 1020 Vienna (Austria)

    2014-04-21T23:59:59.000Z

    We experimentally determine tensile force–elongation diagrams of tapered optical fibers with a nanofiber waist. The tapered optical fibers are produced from standard silica optical fibers using a heat and pull process. Both, the force–elongation data and scanning electron microscope images of the rupture points indicate a brittle material. Despite the small waist radii of only a few hundred nanometers, our experimental data can be fully explained by a nonlinear stress–strain model that relies on material properties of macroscopic silica optical fibers. This is an important asset when it comes to designing miniaturized optical elements as one can rely on the well-founded material characteristics of standard optical fibers. Based on this understanding, we demonstrate a simple and non-destructive technique that allows us to determine the waist radius of the tapered optical fiber. We find excellent agreement with independent scanning electron microscope measurements of the waist radius.

  15. SURFACTANT - POLYMER INTERACTION FOR IMPROVED OIL RECOVERY

    SciTech Connect (OSTI)

    Unknown

    1998-10-01T23:59:59.000Z

    The goal of this research is to use the interaction between a surfactant and a polymer for efficient displacement of tertiary oil by improving slug integrity, adsorption and mobility control. Surfactant--polymer flooding has been shown to be highly effective in laboratory-scale linear floods. The focus of this proposal is to design an inexpensive surfactant-polymer mixture that can efficiently recover tertiary oil by avoiding surfactant slug degradation high adsorption and viscous/heterogeneity fingering. A mixture comprising a ''pseudo oil'' with appropriate surfactant and polymer has been selected to study micellar-polymer chemical flooding. The physical properties and phase behavior of this system have been determined. A surfactant-polymer slug has been designed to achieve high efficiency recovery by improving phase behavior and mobility control. Recovery experiments have been performed on linear cores and a quarter 5-spot. The same recovery experiments have been simulated using a commercially available simulator (UTCHEM). Good agreement between experimental data and simulation results has been achieved.

  16. Silane Modification of Glass and Silica Surfaces to Obtain Equally Oil-Wet Surfaces in Glass-Covered Silicon Micromodel Applications

    SciTech Connect (OSTI)

    Grate, Jay W.; Warner, Marvin G.; Pittman, Jonathan W.; Dehoff, Karl J.; Wietsma, Thomas W.; Zhang, Changyong; Oostrom, Martinus

    2013-08-05T23:59:59.000Z

    The wettability of silicon and glass surfaces can be modified by silanization. However, similar treatments of glass and silica surfaces using the same silane do not necessarily yield the same wettability as determined by the oil-water contact angle. In this technical note, surface cleaning pretreatments were investigated to determine conditions that would yield oil-wet surfaces on glass with similar wettability to silica surfaces treated with the same silane, and both air-water and oil-water contact angles were determined. Air-water contact angles were less sensitive to differences between silanized silica and glass surfaces, often yielding similar values while the oil-water contact angles were quite different. Borosilicate glass surfaces cleaned with standard cleaning solution 1 (SC1) yield intermediate-wet surfaces when silanized with hexamethyldisilazane, while the same cleaning and silanization yields oil-wet surfaces on silica. However, cleaning glass in boiling concentrated nitric acid creates a surface that can be silanized to obtain oil-wet surfaces using HDMS. Moreover, this method is effective on glass with prior thermal treatment at an elevated temperature of 400oC. In this way, silica and glass can be silanized to obtain equally oil-wet surfaces using HMDS. It is demonstrated that pretreatment and silanization is feasible in silicon-silica/glass micromodels previously assembled by anodic bonding, and that the change in wettability has a significant observable effect on immiscisble fluid displacements in the pore network.

  17. Silica powders for powder evacuated thermal insulating panel and method

    DOE Patents [OSTI]

    Harris, M.T.; Basaran, O.A.; Kollie, T.G.; Weaver, F.J.

    1996-01-02T23:59:59.000Z

    A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g/cm{sup 3} and an external surface area in the range of about 90 to 600 m{sup 2}/g is described. The silica powders are prepared by reacting a tetraalkyl silicate with ammonia and water in an alcohol solvent, distilling the solution after the reaction to remove the ammonia and recover the alcohol. The resulting aqueous slurry was dried, ball-milled, and dried again to provide the silica particles with defined internal and external porosity. The nanometer size and the large external surface area of the silica particles along with the internal and external porosity of the silica particles provide powder evacuated thermal insulating panels with significantly higher R-values than obtainable using previously known silica powders. 2 figs.

  18. Silica powders for powder evacuated thermal insulating panel and method

    DOE Patents [OSTI]

    Harris, Michael T. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN); Kollie, Thomas G. (Oak Ridge, TN); Weaver, Fred J. (Knoxville, TN)

    1996-01-01T23:59:59.000Z

    A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2/ g is described. The silica powders are prepared by reacting a tetraakyl silicate with ammonia and water in an alcohol solvent, distilling the solution after the reaction to remove the ammonia and recover the alcohol. The resulting aqueous slurry was dried, ball-milled, and dried again to provide the silica particles with defined internal and external porosity. The nanometer size and the large external surface area of the silica particles along with the internal and external porosity of the silica particles provide powder evacuated thermal insulating panels with significantly higher R-values than obtainable using previously known silica powders.

  19. Silica powders for powder evacuated thermal insulating panel and method

    DOE Patents [OSTI]

    Harris, Michael T. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN); Kollie, Thomas G. (Oak Ridge, TN); Weaver, Fred J. (Knoxville, TN)

    1994-01-01T23:59:59.000Z

    A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2 /g is described. The silica powders are prepared by reacting a tetraakyl silicate with ammonia and water in an alcohol solvent, distilling the solution after the reaction to remove the ammonia and recover the alcohol. The resulting aqueous slurry was dried, ball-milled, and dried again to provide the silica particles with defined internal and external porosity. The nanometer size and the large external surface area of the silica particles along with the internal and external porosity of the silica particles provide powder evacuated thermal insulating panels with significantly higher R-values than obtainable using previously known silica powders.

  20. Silica powders for powder evacuated thermal insulating panel and method

    DOE Patents [OSTI]

    Harris, Michael T. (Knoxville, TN); Basaran, Osman A. (Oak Ridge, TN); Kollie, Thomas G. (Oak Ridge, TN); Weaver, Fred J. (Knoxville, TN)

    1995-01-01T23:59:59.000Z

    A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g/cm.sup.3 and an external surface area in the range of about 90 to 600 m.sup.2/ g is described. The silica powders are prepared by reacting a tetraakyl silicate with ammonia and water in an alcohol solvent, distilling the solution after the reaction to remove the ammonia and recover the alcohol. The resulting aqueous slurry was dried, ball-milled, and dried again to provide the silica particles with defined internal and external porosity. The nanometer size and the large external surface area of the silica particles along with the internal and external porosity of the silica particles provide powder evacuated thermal insulating panels with significantly higher R-values than obtainable using previously known silica powders.

  1. Polymers 2014, 6, 311-326; doi:10.3390/polym6020311 ISSN 2073-4360

    E-Print Network [OSTI]

    Takada, Shoji

    #12;Polymers 2014, 6, 311-326; doi:10.3390/polym6020311 polymers ISSN 2073-4360 www.mdpi.com/journal/polymers copolymers, star polymers, and concentrated polymer brushes on solid surfaces were prepared using living catalysts; block copolymers; triblock copolymers; star polymers; polymer brushes OPEN ACCESS #12;Polymers

  2. Melons are branched polymers

    E-Print Network [OSTI]

    Razvan Gurau; James P. Ryan

    2013-02-18T23:59:59.000Z

    Melonic graphs constitute the family of graphs arising at leading order in the 1/N expansion of tensor models. They were shown to lead to a continuum phase, reminiscent of branched polymers. We show here that they are in fact precisely branched polymers, that is, they possess Hausdorff dimension 2 and spectral dimension 4/3.

  3. Stiff quantum polymers

    E-Print Network [OSTI]

    H. Kleinert

    2009-10-19T23:59:59.000Z

    At ultralow temperatures, polymers exhibit quantum behavior, which is calculated here for the second and fourth moments of the end-to-end distribution in the large-stiffness regime. The result should be measurable for polymers in wide optical traps.

  4. Porous polymer media

    DOE Patents [OSTI]

    Shepodd, Timothy J. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    Highly crosslinked monolithic porous polymer materials for chromatographic applications. By using solvent compositions that provide not only for polymerization of acrylate monomers in such a fashion that a porous polymer network is formed prior to phase separation but also for exchanging the polymerization solvent for a running buffer using electroosmotic flow, the need for high pressure purging is eliminated. The polymer materials have been shown to be an effective capillary electrochromatographic separations medium at lower field strengths than conventional polymer media. Further, because of their highly crosslinked nature these polymer materials are structurally stable in a wide range of organic and aqueous solvents and over a pH range of 2-12.

  5. Developing a Process for Commercial Silica Production from Geothermal Brines

    SciTech Connect (OSTI)

    Bourcier, W; Martin, S; Viani, B; Bruton, C

    2001-04-11T23:59:59.000Z

    Useful mineral by-products can be produced from geothermal brines. Although silica has many commercial uses, problems remain in producing a marketable product. We are conducting laboratory and modeling studies aimed at optimizing for rubber additive use, the properties of silica precipitates from Salton Sea and Coso-like geothermal fluids, Our goal is to develop a robust technique for producing silicas that have desirable physical and chemical properties for commercial use, while developing a generic understanding of silica precipitation that will allow extraction to be extended to additional fluid types, and to be easily modified to produce new types of marketable silica. Our experiments start with an acidified geothermal fluid similar to those treated by pH modification technology. Silica precipitation is induced by adding base and/or adding Mg or Ca salts to affect the nature of the precipitate. For the analog Salton Sea fluids, adding base alone caused silica to precipitate fairly rapidly. To date, we have characterized precipitates from experiments in which the final pH varied from 4 to 8, where NaOH and Na{sub 2}C0{sub 3} were added as bases, and CaCl{sub 2} and MgCl{sub 2} were added as salts. SEM photos of the silica precipitates from the Salton Sea and Cos0 fluids show that the silica particles are clusters of smaller silica particles down to the resolution of the SEM (about 80-100 nm in diameter). The particle sizes and surface areas of silicas from the Salton Sea and Coso analog brines are similar to the properties of the Degussa silica commonly used as a rubber additive. An evaluation of the strength of the silica-organic bond as tested by dispersion in oil (polybutadiene) was inconclusive. Neither the Degussa materials nor our laboratory precipitates dispersed readily in nor dispersed down to the fundamental particle size. Preliminary NMR data indicates that the Degussa silica has a smaller degree of silica polymerization (a slightly smaller average number of Si-0 bonds per silica tetrahedron) than the synthetic samples, but a comparable degree of hydrogen bonding of the surface silanol sites.

  6. acid functionalized silica: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    between pores in SBA-15 mesostructured silicas as a function of the temperature of synthesis Mathematics Websites Summary: Functional Materials, Department of Chemistry...

  7. aperture fused silica: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    fast and deep Tang, William C 6 At-wavelength characterization of UV-radiation-induced damage in fused silica Physics Websites Summary: At-wavelength characterization of...

  8. Influence of amorphous silica on the hydration in ultra-high performance concrete

    SciTech Connect (OSTI)

    Oertel, Tina, E-mail: tina.oertel@isc.fraunhofer.de [Fraunhofer–Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Inorganic Chemistry I, Universität Bayreuth, Universitätsstr. 30, 95440 Bayreuth (Germany); Helbig, Uta, E-mail: uta.helbig@th-nuernberg.de [Crystallography and X-ray Methods, Technische Hochschule Nürnberg Georg Simon Ohm, Wassertorstraße 10, 90489 Nürnberg (Germany); Hutter, Frank [Fraunhofer–Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Kletti, Holger [Building Materials, Bauhaus–Universität Weimar, Coudraystr. 11, 99423 Weimar (Germany); Sextl, Gerhard [Fraunhofer–Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Chemical Technology of Advanced Materials, Julius Maximilian Universität, Röntgenring 11, 97070 Würzburg (Germany)

    2014-04-01T23:59:59.000Z

    Amorphous silica particles (silica) are used in ultra-high performance concretes to densify the microstructure and accelerate the clinker hydration. It is still unclear whether silica predominantly increases the surface for the nucleation of C–S–H phases or dissolves and reacts pozzolanically. Furthermore, varying types of silica may have different and time dependent effects on the clinker hydration. The effects of different silica types were compared in this study by calorimetric analysis, scanning and transmission electron microscopy, in situ X-ray diffraction and compressive strength measurements. The silica component was silica fume, pyrogenic silica or silica synthesized by a wet-chemical route (Stoeber particles). Water-to-cement ratios were 0.23. Differences are observed between the silica for short reaction times (up to 3 days). Results indicate that silica fume and pyrogenic silica accelerate alite hydration by increasing the surface for nucleation of C–S–H phases whereas Stoeber particles show no accelerating effect.

  9. POLYMER PROGRAM SEMINAR "Polymer Nanofibers: Electrospinning, Structure, and Properties"

    E-Print Network [OSTI]

    Alpay, S. Pamir

    POLYMER PROGRAM SEMINAR "Polymer Nanofibers: Electrospinning, Structure, and Properties" Dr. Masaya been widely employed as a technique to produce sub-micron and nanometer scale polymer fibers. The technique utilizes electrical forces induced by a high voltage to draw charged polymer solution jet

  10. Polymer-Metal Nanocomposites via Polymer Thin Film

    E-Print Network [OSTI]

    Shyamasundar, R.K.

    Polymer-Metal Nanocomposites via Polymer Thin Film T. P. Radhakrishnan School of Chemistry, University of Hyderabad Polymer-metal nanocomposite thin films are versatile materials that not only Chemistry Inside a Polymer Thin Film P. Radhakrishnan School of Chemistry, University of Hyderabad metal

  11. On hereditary models of polymers

    E-Print Network [OSTI]

    M. De Angelis

    2012-03-02T23:59:59.000Z

    An equivalence between an integro-differential operator M and an evolution operator Ln is determined. From this equivalence the fundamental solution of Ln is estimated in terms of the fundamental solution related to the third-order operator L1 whose behavior is now available. Moreover, properties typical of wave hierarchies can be applied to polymeric materials. As an example the case n= 2 is considered and results are applied to the Rouse model and the reptation model which describe different aspects of polymer chains.

  12. Thermosetting Polymer-Matrix Composites for Strucutral Repair Applications

    SciTech Connect (OSTI)

    William Kirby Goertzen

    2007-12-01T23:59:59.000Z

    Several classes of thermosetting polymer matrix composites were evaluated for use in structural repair applications. Initial work involved the characterization and evaluation of woven carbon fiber/epoxy matrix composites for structural pipeline repair. Cyanate ester resins were evaluated as a replacement for epoxy in composites for high-temperature pipe repair applications, and as the basis for adhesives for resin infusion repair of high-temperature composite materials. Carbon fiber/cyanate ester matrix composites and fumed silica/cyanate ester nanocomposites were evaluated for their thermal, mechanical, viscoelastic, and rheological properties as they relate to their structure, chemistry, and processing characteristics. The bisphenol E cyanate ester under investigation possesses a high glass transition temperature, excellent mechanical properties, and unique ambient temperature processability. The incorporate of fumed silica served to enhance the mechanical and rheological properties of the polymer and reduce thermal expansion without sacrificing glass transition or drastically altering curing kinetics. Characterization of the composites included dynamic mechanical analysis, thermomechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy.

  13. Determining boiler-water makeup

    SciTech Connect (OSTI)

    Beecher, J.; Herman, K. [Ashland Chemical Co., Boonton, NJ (United States). Drew Industrial Div.

    1995-10-01T23:59:59.000Z

    In boiler operations, it is desirable to determine blowdown--and, thus, the feedwater`s concentration cycles--because it enables operators to calculate the theoretical concentrations of iron, copper or dispersant in the system. These calculations are important for maintaining boiler cleanliness. In practice, however, it isn`t always feasible to determine blowdown. For example, if the steam, feedwater and blowdown flows are not measured in a system, or if the measurements are not accurate, the blowdown and feedwater concentration cycles cannot be accurately determined. Also, if demineralized makeup water with very-low silica concentrations is mixed with essentially silica-free condensate, the ratio of silica in the boiler water to the silica in the feedwater may not yield accurate values for the concentration cycle. This method for calculating concentration cycles is accurate to within 5%, when the accuracy of the parameters measured are within the following limits: steam flow (2%); phosphate, residual (5%); micro calcium (50%); micro iron (25%); and phosphate, feed (10%).

  14. SILICA GEL BEHAVIOR UNDER DIFFERENT EGS CHEMICAL AND THERMAL CONDITIONS: AN EXPERIMENTAL STUDY

    SciTech Connect (OSTI)

    Hunt, J D; Ezzedine, S M; Bourcier, W; Roberts, S

    2012-01-19T23:59:59.000Z

    Fractures and fracture networks are the principal pathways for migration of water and contaminants in groundwater systems, fluids in enhanced geothermal systems (EGS), oil and gas in petroleum reservoirs, carbon dioxide leakage from geological carbon sequestration, and radioactive and toxic industrial wastes from underground storage repositories. When dealing with EGS fracture networks, there are several major issues to consider, e.g., the minimization of hydraulic short circuits and losses of injected geothermal fluid to the surrounding formation, which in turn maximize heat extraction and economic production. Gel deployments to direct and control fluid flow have been extensively and successfully used in the oil industry for enhanced oil recovery. However, to the best of our knowledge, gels have not been applied to EGS to enhance heat extraction. In-situ gelling systems can either be organic or inorganic. Organic polymer gels are generally not thermostable to the typical temperatures of EGS systems. Inorganic gels, such as colloidal silica gels, however, may be ideal blocking agents for EGS systems if suitable gelation times can be achieved. In the current study, we explore colloidal silica gelation times and rheology as a function of SiO{sub 2} concentration, pH, salt concentration, and temperature, with preliminary results in the two-phase field above 100 C. Results at 25 C show that it may be possible to choose formulations that will gel in a reasonable and predictable amount of time at the temperatures of EGS systems.

  15. High resolution transmission electron microscopy of melamine-formaldehyde aerogels and silica aerogels

    SciTech Connect (OSTI)

    Ruben, G.C. (Dartmouth Coll., Hanover, NH (United States). Dept. of Biological Sciences)

    1991-09-01T23:59:59.000Z

    The goal of the high resolution transmission electron microscopy (HRTEM) was to image the structure of two tetramethyl orthosilicate (TMOS) and two melamine-formaldehyde (MF) aerogels at the single polymer chain level{sup 1,2}. With this level of structural resolution we hoped to interrelate each aerogel's structure with its physical properties and its method of synthesis. Conventional single-step base catalysed TMOS aerogels show strings of spheroidal particles linked together with minimal necking. The spheroidal particles range from 86--132 {Angstrom} and average 113{plus minus}10 {Angstrom} in diameter{sup 2}. In contrast the TMOS aerogels reported on here were made by a two step method. After extended silica chains are grown in solution under acidic conditions with a substoichiometric amount of water, the reaction is stopped and the methanol hydrolysed from TMOS is removed. Then base catalysis and additional water are added to cause gel formation is a nonalcoholic solvent. The MF aerogels were prepared for HRTEM by fracturing them on a stereo microscope stage with razor knife so that fractured pieces with smooth flat surfaces could be selected for platinum-carbon replication. The two silica (TMOS) aerogels were both transparent and difficult to see. These aerogels were fractured on a stereo microscope stage with tweezers. 6 refs., 4 figs.

  16. Influence of confinement on polymer-electrolyte relaxational dynamics.

    SciTech Connect (OSTI)

    Zanotti, J.-M.; Smith, L. J.; Price, D. L.; Saboungi, M.-L.; Intense Pulsed Neutron Source; Lab. Leon Brillouin (CEA-CRNS); Clark Univ.; CRMHT (CNRS); CRMD (CNRS)

    2004-01-01T23:59:59.000Z

    Conception and industrial production of viable high specific energy/power batteries is a central issue for the development of non-polluting vehicles. In terms of stored energy and safety, solid-state devices using polymer electrolytes are highly desirable. One of the most studied systems is PEO (polyethylene oxide) complexed by Li salts. Polymer segmental motions and ionic conductivity are closely related. Bulk PEO is actually a biphasic system where an amorphous and a crystalline state (Tm 335 K) coexist. To improve ionic conduction in those systems requires a significant increase of the amorphous phase fraction where lithium conduction is known to mainly take place. Confinement strongly affects properties of condensed matter and in particular the collective phenomena inducing crystallization. Confinement of the polymer matrix is therefore a possible alternative route to the unpractical use of high temperature. Results of a quasi-elastic incoherent neutron scattering study of the influence of confinement on polyethylene oxide (PEO) and (PEO)8Li+[(CF3SO2)2N]- (or (POE)8LiTFSI) dynamics are presented. The nano-confining media is Vycor, a silica based hydrophilic porous glass (characteristic size of the 3D pore network 50 {angstrom}). As expected, the presence of Li salt slows down the bulk polymer dynamics. The confinement also affects dramatically the apparent mean-square displacement of the polymer. Local relaxational PEO dynamics is described KWW model. We also present an alternate model and show how the detailed polymer dynamics (correlation times and local geometry of the motions) can be described without the use of such stretched exponentials so as to access a rheology-related meaningful physical quantity: the monomeric friction coefficient.

  17. Segregation of Polymers in Confined Spaces

    E-Print Network [OSTI]

    Ya Liu; Bulbul Chakraborty

    2009-08-10T23:59:59.000Z

    We investigate the motion of two overlapping polymers with self-avoidance confined in a narrow 2d box. A statistical model is constructed using blob free-energy arguments. We find spontaneous segregation under the condition: $L > R_{//}$, and mixing under $L < R_{//}$, where L is the length of the box, and $R_{//}$ the polymer extension in an infinite slit. Segregation time scales are determined by solving a mean first-passage time problem, and by performing Monte Carlo simulations. Predictions of the two methods show good agreement. Our results may elucidate a driving force for chromosomes segregation in bacteria.

  18. Fibrous composites comprising carbon nanotubes and silica

    DOE Patents [OSTI]

    Peng, Huisheng (Shanghai, CN); Zhu, Yuntian Theodore (Cary, NC); Peterson, Dean E. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM)

    2011-10-11T23:59:59.000Z

    Fibrous composite comprising a plurality of carbon nanotubes; and a silica-containing moiety having one of the structures: (SiO).sub.3Si--(CH.sub.2).sub.n--NR.sub.1R.sub.2) or (SiO).sub.3Si--(CH.sub.2).sub.n--NCO; where n is from 1 to 6, and R.sub.1 and R.sub.2 are each independently H, CH.sub.3, or C.sub.2H.sub.5.

  19. Hydrophobic silica aerogel production at KEK

    E-Print Network [OSTI]

    Tabata, Makoto; Kawai, Hideyuki; Sumiyoshi, Takayuki; Yokogawa, Hiroshi

    2011-01-01T23:59:59.000Z

    We present herein a characterization of a standard method used at the High Energy Accelerator Research Organization (KEK) to produce hydrophobic silica aerogels and expand this method to obtain a wide range of refractive index (n = 1.006-1.14). We describe in detail the entire production process and explain the methods used to measure the characteristic parameters of aerogels, namely the refractive index, transmittance, and density. We use a small-angle X-ray scattering (SAXS) technique to relate the transparency to the fine structure of aerogels.

  20. Hydrophobic silica aerogel production at KEK

    E-Print Network [OSTI]

    Makoto Tabata; Ichiro Adachi; Hideyuki Kawai; Takayuki Sumiyoshi; Hiroshi Yokogawa

    2011-12-14T23:59:59.000Z

    We present herein a characterization of a standard method used at the High Energy Accelerator Research Organization (KEK) to produce hydrophobic silica aerogels and expand this method to obtain a wide range of refractive index (n = 1.006-1.14). We describe in detail the entire production process and explain the methods used to measure the characteristic parameters of aerogels, namely the refractive index, transmittance, and density. We use a small-angle X-ray scattering (SAXS) technique to relate the transparency to the fine structure of aerogels.

  1. Silvered polymer reflectors

    SciTech Connect (OSTI)

    Schissel, P.; Neidlinger, H.H.; Czanderna, A.W.

    1985-03-01T23:59:59.000Z

    One of the principal objectives of the Solar Thermal Research Program is to develop silvered polymer films for constructing durable, low-cost, lightweight concentrating collectors for high temperature solar thermal systems. The mirrors are characterized for their solar-weighted (air mass 1.5) reflectance and exposed to environmental degradation. Photodegradation of polymers has also been studied using Fourier transform infrared spectroscopy supplemented with surface analysis characterization. Results are discussed for extruded films, ultraviolet effects, metallization, and the effects of polymer additives. (LEW)

  2. Plastic flow modeling in glassy polymers

    SciTech Connect (OSTI)

    Clements, Brad [Los Alamos National Laboratory

    2010-12-13T23:59:59.000Z

    Glassy amorphous and semi-crystalline polymers exhibit strong rate, temperature, and pressure dependent polymeric yield. As a rule of thumb, in uniaxial compression experiments the yield stress increases with the loading rate and applied pressure, and decreases as the temperature increases. Moreover, by varying the loading state itself complex yield behavior can be observed. One example that illustrates this complexity is that most polymers in their glassy regimes (i.e., when the temperature is below their characteristic glass transition temperature) exhibit very pronounced yield in their uniaxial stress stress-strain response but very nebulous yield in their uniaxial strain response. In uniaxial compression, a prototypical glassy-polymer stress-strain curve has a stress plateau, often followed by softening, and upon further straining, a hardening response. Uniaxial compression experiments of this type are typically done from rates of 10{sup -5} s{sup -1} up to about 1 s{sup -1}. At still higher rates, say at several thousands per second as determined from Split Hopkinson Pressure Bar experiments, the yield can again be measured and is consistent with the above rule of thumb. One might expect that that these two sets of experiments should allow for a successful extrapolation to yet higher rates. A standard means to probe high rates (on the order of 105-107 S-I) is to use a uniaxial strain plate impact experiment. It is well known that in plate impact experiments on metals that the yield stress is manifested in a well-defined Hugoniot Elastic Limit (HEL). In contrast however, when plate impact experiments are done on glassy polymers, the HEL is arguably not observed, let alone observed at the stress estimated by extrapolating from the lower strain rate experiments. One might argue that polymer yield is still active but somehow masked by the experiment. After reviewing relevant experiments, we attempt to address this issue. We begin by first presenting our recently developed glassy polymer model. While polymers are well known for their non-equilibrium deviatoric behavior we have found the need for incorporating both equilibrium and non-equilibrium volumetric behavior into our theory. Experimental evidence supporting the notion of non-equilibrium volumetric behavior will be summarized. Our polymer yield model accurately captures the stress plateau, softening and hardening and its yield stress predictions agree well with measured values for several glassy polymers including PMMA, PC, and an epoxy resin. We then apply our theory to plate impact experiments in an attempt to address the questions associated with high rate polymer yield in uniaxial strain configurations.

  3. ALUMINOSILICATE-COATED SILICA SAND FOR REACTIVE TRANSPORT EXPERIMENTS

    E-Print Network [OSTI]

    Flury, Markus

    ALUMINOSILICATE-COATED SILICA SAND FOR REACTIVE TRANSPORT EXPERIMENTS By JORGE ANTONIO JEREZ transport experiments; Dr. Barbara Williams and Jason Shira from University of Idaho for providing access-COATED SILICA SAND FOR REACTIVE TRANSPORT EXPERIMENTS Abstract by Jorge Antonio Jerez Briones, Ph.D. Washington

  4. Learn about the dangers of breathing silica dust

    E-Print Network [OSTI]

    Knowles, David William

    dust builds up in your lungs, you are at risk of developing a serious and irreversible lung disease silica dust. The fine particles are deposited in the lungs, causing thickening and scarring of the lung tissue. Crystalline silica exposure has also been linked to lung cancer. A worker may develop any

  5. Community Geothermal Technology Program: Silica bronze project. Final report

    SciTech Connect (OSTI)

    Bianchini, H.

    1989-10-01T23:59:59.000Z

    Objective was to incorporate waste silica from the HGP-A geothermal well in Pohoiki with other refractory materials for investment casting of bronze sculpture. The best composition for casting is about 50% silica, 25% red cinders, and 25% brick dust; remaining ingredient is a binder, such as plaster and water.

  6. High-Q silica zipper cavity for optical radiation pressure driven MOMS switch

    SciTech Connect (OSTI)

    Tetsumoto, Tomohiro; Tanabe, Takasumi, E-mail: takasumi@elec.keio.ac.jp [Department of Electronics and Electrical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi Kohoku, Yokohama 223-8522 (Japan)

    2014-07-15T23:59:59.000Z

    We design a silica zipper cavity that has high optical and mechanical Q (quality factor) values and demonstrate numerically the feasibility of a radiation pressure driven micro opto-mechanical system (MOMS) directional switch. The silica zipper cavity has an optical Q of 4.0 × 10{sup 4} and an effective mode volume V{sub mode} of 0.67?{sup 3} when the gap between two cavities is 34 nm. The mechanical Q (Q{sub m}) is determined by thermo-elastic damping and is 2.0 × 10{sup 6} in a vacuum at room temperature. The opto-mechanical coupling rate g{sub OM} is as high as 100 GHz/nm, which allows us to move the directional cavity-waveguide system and switch 1550-nm light with 770-nm light by controlling the radiation pressure.

  7. Sulfonated polyphenylene polymers

    DOE Patents [OSTI]

    Cornelius, Christopher J. (Albuquerque, NM); Fujimoto, Cy H. (Albuquerque, NM); Hickner, Michael A. (Albuquerque, NM)

    2007-11-27T23:59:59.000Z

    Improved sulfonated polyphenylene compositions, improved polymer electrolyte membranes and nanocomposites formed there from for use in fuel cells are described herein. The improved compositions, membranes and nanocomposites formed there from overcome limitations of Nafion.RTM. membranes.

  8. Polymer quantization and Symmetries

    E-Print Network [OSTI]

    Ghanashyam Date; Nirmalya Kajuri

    2013-02-24T23:59:59.000Z

    Polymer quantization was discovered during the construction of Loop Quantum Cosmology. For the simplest quantum theory of one degree of freedom, the implications for dynamics were studied for the harmonic oscillator as well as some other potentials. For more degrees of freedom, the possibility of continuous, kinematic symmetries arises. While these are realised on the Hilbert space of polymer quantum mechanics, their infinitesimal versions are not supported. For an invariant Hamiltonian, these symmetry realizations imply infinite degeneracy suggesting that the symmetry should be spontaneously or explicitly broken. The estimation of symmetry violations in some cases have been analysed before. Here we explore the alternative of shifting the arena to the distributional states. We discuss both the polymer quantum mechanics case as well as polymer quantized scalar field.

  9. Heavily fluorinated electronic polymers

    E-Print Network [OSTI]

    Lim, Jeewoo

    2011-01-01T23:59:59.000Z

    Building blocks, containing majority fluorine content by weight, for PPEs and PPVs have been synthesized. Some of the monomers were shown to give exclusively fluorous-phase soluble polymers, the syntheses of which were ...

  10. Conducting polymer nanostructures for biological applications

    E-Print Network [OSTI]

    Berdichevsky, Yevgeny

    2006-01-01T23:59:59.000Z

    of Electronically Conductive Polymer Nanostructures,” Acc.et al. , “Conjugated-Polymer Micro- and Milliactuators for3. Y. Berdichevsky, Y. -H. Lo, “Polymer Microvalve Based on

  11. Non-Markovian polymer reaction kinetics

    E-Print Network [OSTI]

    Thomas Guérin; Olivier Bénichou; Raphaël Voituriez

    2012-09-07T23:59:59.000Z

    Describing the kinetics of polymer reactions, such as the formation of loops and hairpins in nucleic acids or polypeptides, is complicated by the structural dynamics of their chains. Although both intramolecular reactions, such as cyclization, and intermolecular reactions have been studied extensively, both experimentally and theoretically, there is to date no exact explicit analytical treatment of transport-limited polymer reaction kinetics, even in the case of the simplest (Rouse) model of monomers connected by linear springs. We introduce a new analytical approach to calculate the mean reaction time of polymer reactions that encompasses the non-Markovian dynamics of monomer motion. This requires that the conformational statistics of the polymer at the very instant of reaction be determined, which provides, as a by-product, new information on the reaction path. We show that the typical reactive conformation of the polymer is more extended than the equilibrium conformation, which leads to reaction times significantly shorter than predicted by the existing classical Markovian theory.

  12. Polymers in disordered environments

    E-Print Network [OSTI]

    V. Blavatska; N. Fricke; W. Janke

    2014-11-18T23:59:59.000Z

    A brief review of our recent studies aiming at a better understanding of the scaling behaviour of polymers in disordered environments is given. The main emphasis is on a simple generic model where the polymers are represented by (interacting) self-avoiding walks and the disordered environment by critical percolation clusters. The scaling behaviour of the number of conformations and their average spatial extent as a function of the number of monomers and the associated critical exponents $\\gamma$ and $\

  13. CX-006831: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    Determination CX-006831: Categorical Exclusion Determination Cost Effective Polymer Solar Cells Research and Education CX(s) Applied: A9, B3.6 Date: 09212011 Location(s):...

  14. Interfacial thermal conductance in spun-cast polymer films and polymer brushes

    E-Print Network [OSTI]

    Braun, Paul

    Interfacial thermal conductance in spun-cast polymer films and polymer brushes Mark D. Losego inorganic materials and anharmonic polymers have potentially intriguing thermal transport behavior. The low thermal conductivity of amorphous polymers limits significant interfacial effects to polymer film

  15. Mesoporous Silica Nanomaterials for Applications in Catalysis, Sensing, Drug Delivery and Gene Transfection

    SciTech Connect (OSTI)

    Daniela Rodica Radu

    2005-12-19T23:59:59.000Z

    The central theme of this dissertation is represented by the versatility of mesoporous silica nanomaterials in various applications such as catalysis and bio-applications, with main focus on biological applications of Mesoporous Silica Nanospheres (MSN). The metamorphosis that we impose to these materials from catalysis to sensing and to drug and gene delivery is detailed in this dissertation. First, we developed a synthetic method that can fine tune the amount of chemically accessible organic functional groups on the pores surface of MSN by exploiting electrostatic and size matching between the cationic alkylammonium head group of the cetyltrimethylammonium bromide (CTAB) surfactant and various anionic organoalkoxysilane precursors at the micelle-water interface in a base-catalyzed condensation reaction of silicate. Aiming nature imitation, we demonstrated the catalytic abilities of the MSNs, We utilized an ethylenediamine functional group for chelating Cu{sup 2+} as a catalytic functional group anchored inside the mesopores. Thus, a polyalkynylene-based conducting polymer (molecular wire) was synthesized within the Cu-functionalized MSNs silica catalyst. For sensing applications, we have synthesized a poly(lactic acid) coated mesoporous silica nanosphere (PLA-MSN) material that serves as a fluorescence sensor system for detection of amino-containing neurotransmitters in neutral aqueous buffer. We exploited the mesoporosity of MSNs for encapsulating pharmaceutical drugs. We examined bio-friendly capping molecules such as polyamidoamine dendrimers of generations G2 to G4, to prevent the drug leaching. Next, the drug delivery system employed MSNs loaded with Doxorubicin, an anticancer drug. The results demonstrated that these nano-Trojan horses have ability to deliver Doxorubicin to cancer cells and induce their death. Finally, to demonstrate the potential of MSN as an universal cellular transmembrane nanovehicle, we anchored positively charged dendrimers on the surface of MSN and utilize them to complex cationic DNA. The p-EGFP-CI gene-coated MSN nanocomposite was able to transfect cancer cell lines, such as human HeLa and CHO cancer cell lines. The gene carrier ability of MSNs was further proved by transfecting primary cells and cotransfecting of two different genes in cancer cell lines. In sum, MSN are versatile partners in several types of applications.

  16. Flory-Huggins theory for the solubility of heterogeneously-modified polymers

    E-Print Network [OSTI]

    Patrick B. Warren

    2007-04-05T23:59:59.000Z

    Many water soluble polymers are chemically modified versions of insoluble base materials such as cellulose. A Flory-Huggins model is solved to determine the effects of heterogeneity in modification on the solubility of such polymers. It is found that heterogeneity leads to decreased solubility, with the effect increasing with increasing blockiness. In the limit of extreme blockiness, the nature of the phase coexistence crosses over to a polymer-polymer demixing transition. Some consequences are discussed for the synthesis of partially modified polymers, and the experimental characterisation of such systems.

  17. Danish Polymer Centre Annual Report 2002

    E-Print Network [OSTI]

    Danish Polymer Centre Annual Report 2002 #12;2 The Danish Polymer Centre, DTU and Risø Annual.1 Polymer based solar cells (photovoltaics) ................................ 5 2.2 Structuring Plastic ........................................................................ 17 2.7 Biodegradable polymer composites .......................................... 19 2

  18. Reaction and spectroscopic study of silica-supported molybdenum(IV) and tungsten(IV) dimers

    SciTech Connect (OSTI)

    Sullivan, D.L.; Roark, R.D.; Ekerdt, J.G. [Univ. of Texas, Austin, TX (United States); Deutsch, S.E.; Gates, B.C. [Univ. of California, Davis, CA (United States)

    1995-03-16T23:59:59.000Z

    Cyclopentadienyl molybdenum di- and tricarbonyl dimer and cyclopentadienyl tungsten di- and tricarbonyl dimer complexes were added to silica as precursors to supported metal dimers. These complexes are shown to yield metal dimers following attachment to the silica and carbonyl ligand removal. Reductive carbonyl coupling of acetaldehyde and acetone was used as a molecular probe to determine whether dimers formed, with each metal atom being in the 4+ oxidation state. Acetaldehyde and acetone reductively coupled to produce cis- and trans-2-butenes and 2,3-dimethyl-2-butene, respectively. Diolates formed as intermediate products during the coupling reaction. Infrared bands were observed at 2969, 2925, and 2859 cm-1 that correspond to {nu}{sub asym}(CH{sub 3}), {nu}(CH), and {nu}{sub sym}(CH{sub 3}), respectively, for the 2,3-butanediolate formed from acetaldehyde. The hydrogens on the methyl groups for the acetone reductive coupling intermediate, 2,3-dimethyl-2,3-butanediolate, were not equivalent, resulting in the appearance of three C-H stretching frequencies at 2977, 2939, and 2891 cm{sup {minus}1} that are assigned to A{prime}{sub asym}, A{prime}, A{prime}{sub sym} of CH{sub 3}, respectively. Extended X-ray absorption fine structure (EXAFS) spectroscopy was used to characterize a sample prepared from cyclopentadienyl tungsten dicarbonyl dimer on silica. 74 refs., 7 figs., 5 tabs.

  19. Ambient-pressure silica aerogel films

    SciTech Connect (OSTI)

    Prakash, S.S. [New Mexico Univ., Albuquerque, NM (United States); Brinker, C.J. [New Mexico Univ., Albuquerque, NM (United States)]|[Sandia National Labs., Albuquerque, NM (United States); Hurd, A.J. [Sandia National Labs., Albuquerque, NM (United States)

    1994-12-31T23:59:59.000Z

    Very highly porous (aerogel) silica films with refractive index in the range 1.006--1.05 (equivalent porosity 98.5--88%) were prepared by an ambient-pressure process. It was shown earlier using in situ ellipsometric imaging that the high porosity of these films was mainly attributable to the dilation or `springback` of the film during the final stage of drying. This finding was irrefutably reconfirmed by visually observing a `springback` of >500% using environmental scanning electron microscopy (ESEM). Ellipsometry and ESEM also established the near cent per cent reversibility of aerogel film deformation during solvent intake and drying. Film thickness profile measurements (near the drying line) for the aerogel, xerogel and pure solvent cases are presented from imaging ellipsometry. The thickness of these films (crack-free) were controlled in the range 0.1-3.5 {mu}m independent of refractive index.

  20. Development of Silica Aerogel with Any Density

    E-Print Network [OSTI]

    M. Tabata; I. Adachi; T. Fukushima; H. Kawai; H. Kishimoto; A. Kuratani; H. Nakayama; S. Nishida; T. Noguchi; K. Okudaira; Y. Tajima; H. Yano; H. Yokogawa; H. Yoshida

    Abstract–New production methods of silica aerogel with high and low refractive indices have been developed. A very slow shrinkage of alcogel at room temperature has made possible producing aerogel with high refractive indices of up to 1.265 without cracks. Even higher refractive indices than 1.08, the transmission length of the aerogel obtained from this technique has been measured to be about 10 to 20 mm at 400 nm wave length. A mold made of alcogel which endures shrinkage in the supercritical drying process has provided aerogel with the extremely low density of 0.009g/cm 3, which corresponds to the refractive index of 1.002. We have succeeded producing aerogel with a wide range of densities. I.

  1. Imaging Hydrated Microbial Extracellular Polymers: Comparative...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron Microscopy . Imaging Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron...

  2. The Polymer Bouncer

    E-Print Network [OSTI]

    A. Martin-Ruiz; A. Frank; L. F. Urrutia

    2015-05-31T23:59:59.000Z

    Polymer Quantization (PQ) is a background independent quantization scheme that is deployed in Loop Quantum Gravity. This framework leads to a new short-distance (discretized) structure characterized by a fundamental length. In this paper we use PQ to analyze the problem of a particle bouncing on a perfectly reflecting surface under the influence of Earth's gravitational field, what we have called "\\textit{The Polymer Bouncer}". In this scenario, deviations from the usual quantum effects are induced by the spatial discreteness, but not by a new short-range gravitational interaction. We solve the polymer Schr\\"odinger equation in an analytical fashion, and we evaluate numerically the corresponding energy levels. We find that the polymer energy spectrum exhibits a negative shift compared to the obtained for the quantum bouncer. The comparison of our results with those obtained in the GRANIT experiment leads to an upper bound for the fundamental length scale, namely $\\lambda \\ll 0.6 \\buildrel _{\\circ} \\over {\\mathrm{A}}$. We find polymer corrections to the probability of transitions between levels, induced by small vibrations, together with the probability of spontaneous emission in the quadrupole approximation.

  3. Sulfate Fining Chemistry in Oxidized and Reduced Soda-Lime-Silica Glasses

    SciTech Connect (OSTI)

    Matyas, Josef; Hrma, Pavel R.

    2005-05-13T23:59:59.000Z

    Various reducing agents were used and their additions were varied to (1) increase glass quality through eliminating defects from silica scum, (2) decrease SOx emissions through changing the kind and quantity of reducing agents, and (3) improve production efficiency through increased flexibility of glass redox control during continuous processing. The work included measuring silica sand dissolution and sulfate decomposition in melts from glass batches. Glass batches were heated at a temperature-increase rate deemed similar to that experienced in the melting furnace. The sulfate decomposition kinetics was investigated with thermogravimetric analysis-differential thermal analysis and evolved gas analysis. Sulfur concentrations in glasses quenched at different temperatures were determined using X-ray fluorescence spectroscopy. The distribution of residual sand (that which was not dissolved during the initial batch reactions) in the glass was obtained as a function of temperature with optical microscopy in thin-sections of melts. The fraction of undissolved sand was measured with X-ray diffraction. The results of the present study helped Visteon Inc. reduce the energy consumption and establish the batch containing 0.118 mass% of graphite as the best candidate for Visteon glass production. The improved glass batch has a lower potential for silica scum formation and for brown fault occurrence in the final glass product. It was established that bubbles trapped in the melt even at 1450 C have a high probability to be refined when reaching the hot zone in the glass furnace. Furthermore, silica sand does not accumulate at the glass surface and dissolves faster in the batch with graphite than in the batch with carbocite.

  4. Origins of secondary silica within Yucca Mountain, Nye County, southwestern Nevada

    SciTech Connect (OSTI)

    Moscati, R.J.; Whelan, J.F.

    1996-09-01T23:59:59.000Z

    The accuracy of predictions of the hydrologic response of Yucca Mountain to future climate depends largely on how well relations between past climate and hydrology can be resolved. To advance this reconstruction, secondary minerals in and near Yucca Mountain, deposited by ground waters that originated both as surficial recharge at Yucca Mountain and from regional aquifers, are being studied to determine past ground-water sources and chemistries. Preliminary data on stable oxygen isotopes indicate that, although silica (opal, quartz, and chalcedony) and calcite and have formed in similar settings and from somewhat similar fluids, the authors have found no compelling evidence of coprecipitation or formation from identical fluids. If verified by further analyses, this precludes the use of silica-calcite mineral pairs for precise geothermometry. The preliminary data also indicate that opal and calcite occurrences in pedogenic and unsaturated-zone settings are invariably compatible with formation under modern ambient surface or subsurface temperatures. Silica and calcite stable-isotope studies are being integrated with soil geochemical modeling. This modeling will define the soil geochemical condition (climate) leading to opal or calcite deposition and to the transfer functions that may apply at the meteorologic soil unsaturated-zone interfaces. Additional study of pedogenic and unsaturated-zone silica is needed to support these models. The hypothesis that the transformation of vapor-phase tridymite to quartz requires saturated conditions is being tested through stable oxygen-isotope studies of lithophysal tridymite/quartz mixtures. Should this hypothesis be verified, mineralogic analysis by X-ray diffraction theoretically would permit reconstruction of past maximum water-table elevations.

  5. Efficient tunable luminescence of SiGe alloy sheet polymers

    SciTech Connect (OSTI)

    Vogg, G.; Meyer, A. J.-P.; Miesner, C.; Brandt, M. S.; Stutzmann, M.

    2001-06-18T23:59:59.000Z

    Crystalline SiGe alloy sheet polymers were topotactically prepared from epitaxially grown calcium germanosilicide Ca(Si{sub 1{minus}x}Ge{sub x}){sub 2} precursor films in the whole composition range. These polygermanosilynes are found to be a well-defined mixture of the known siloxene and polygermyne sheet polymers with the OH groups exclusively bonded to silicon. The optical properties determined by photoluminescence and optical reflection measurements identify the mixed SiGe sheet polymers as direct semiconductors with efficient luminescence tunable in the energy range between 2.4 and 1.3 eV. {copyright} 2001 American Institute of Physics.

  6. Solid polymer electrolyte from phosphorylated chitosan

    SciTech Connect (OSTI)

    Fauzi, Iqbal, E-mail: arcana@chem.itb.ac.id; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Groups, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24T23:59:59.000Z

    Recently, the need of secondary battery application continues to increase. The secondary battery which using a liquid electrolyte was indicated had some weakness. A solid polymer electrolyte is an alternative electrolytes membrane which developed in order to replace the liquid electrolyte type. In the present study, the effect of phosphorylation on to polymer electrolyte membrane which synthesized from chitosan and lithium perchlorate salts was investigated. The effect of the component’s composition respectively on the properties of polymer electrolyte, was carried out by analyzed of it’s characterization such as functional groups, ion conductivity, and thermal properties. The mechanical properties i.e tensile resistance and the morphology structure of membrane surface were determined. The phosphorylation processing of polymer electrolyte membrane of chitosan and lithium perchlorate was conducted by immersing with phosphoric acid for 2 hours, and then irradiated on a microwave for 60 seconds. The degree of deacetylation of chitosan derived from shrimp shells was obtained around 75.4%. Relative molecular mass of chitosan was obtained by viscometry method is 796,792 g/mol. The ionic conductivity of chitosan membrane was increase from 6.33 × 10{sup ?6} S/cm up to 6.01 × 10{sup ?4} S/cm after adding by 15 % solution of lithium perchlorate. After phosphorylation, the ionic conductivity of phosphorylated lithium chitosan membrane was observed 1.37 × 10{sup ?3} S/cm, while the tensile resistance of 40.2 MPa with a better thermal resistance. On the strength of electrolyte membrane properties, this polymer electrolyte membrane was suggested had one potential used for polymer electrolyte in field of lithium battery applications.

  7. Branched Polymers and Hyperplane Arrangements

    E-Print Network [OSTI]

    Postnikov, Alexander

    We generalize the construction of connected branched polymers and the notion of the volume of the space of connected branched polymers studied by Brydges and Imbrie (Ann Math, 158:1019–1039, 2003), and Kenyon and Winkler ...

  8. Fluctuations of ring polymers

    E-Print Network [OSTI]

    Medalion, Shlomi; Meirovitch, Hagai; Barkai, Eli; Kessler, David A

    2015-01-01T23:59:59.000Z

    We present an exact solution for the distribution of sample averaged monomer to monomer distance of ring polymers. For non-interacting and weakly-interacting models these distributions correspond to the distribution of the area under the reflected Bessel bridge and the Bessel excursion respectively, and are shown to be identical in dimension d greater or equal 2. A symmetry of the problem reveals that dimension d and 4 minus d are equivalent, thus the celebrated Airy distribution describing the areal distribution of the one dimensional Brownian excursion describes also a polymer in three dimensions. For a self-avoiding polymer in dimension d we find numerically that the fluctuations of the scaled averaged distance are nearly identical in dimensions 2 and 3, and are well described to a first approximation by the non-interacting excursion model in dimension 5.

  9. Antithrombogenic Polymer Coating.

    DOE Patents [OSTI]

    Huang, Zhi Heng (San Ramon, CA); McDonald, William F. (Utica, OH); Wright, Stacy C. (Flint, MI); Taylor, Andrew C. (Ann Arbor, MI)

    2003-01-21T23:59:59.000Z

    An article having a non-thrombogenic surface and a process for making the article are disclosed. The article is formed by (i) coating a polymeric substrate with a crosslinked chemical combination of a polymer having at least two amino substituted side chains, a crosslinking agent containing at least two crosslinking functional groups which react with amino groups on the polymer, and a linking agent containing a first functional group which reacts with a third functional group of the crosslinking agent, and (ii) contacting the coating on the substrate with an antithrombogenic agent which covalently bonds to a second functional group of the linking agent. In one example embodiment, the polymer is a polyamide having amino substituted alkyl chains on one side of the polyamide backbone, the crosslinking agent is a phosphine having the general formula (A).sub.3 P wherein A is hydroxyalkyl, the linking agent is a polyhydrazide and the antithrombogenic agent is heparin.

  10. Shape memory polymer medical device

    DOE Patents [OSTI]

    Maitland, Duncan (Pleasant Hill, CA); Benett, William J. (Livermore, CA); Bearinger, Jane P. (Livermore, CA); Wilson, Thomas S. (San Leandro, CA); Small, IV, Ward (Livermore, CA); Schumann, Daniel L. (Concord, CA); Jensen, Wayne A. (Livermore, CA); Ortega, Jason M. (Pacifica, CA); Marion, III, John E. (Livermore, CA); Loge, Jeffrey M. (Stockton, CA)

    2010-06-29T23:59:59.000Z

    A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.

  11. BRANCHED POLYMERS AND HYPERPLANE ARRANGEMENTS

    E-Print Network [OSTI]

    Postnikov, Alexander

    BRANCHED POLYMERS AND HYPERPLANE ARRANGEMENTS KAROLA M´ESZ´AROS ALEXANDER POSTNIKOV Abstract. We of connected branched polymers studied by Brydges and Imbrie [BI], and Kenyon and Winkler [KW] to any hyperplane arrangement A. The volume of the resulting configuration space of connected branched polymers

  12. aminopropyl silica gel: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Summary: We present optical and X-ray radiographical characterization of silica aerogels with refractive index from 1.05 to 1.07 for a Cherenkov radiator. A novel pin-drying...

  13. amorphous silica systems: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    progress in the development and mass production of large-area hydrophobic silica aerogels for use as radiators in the aerogel-based ring-imaging Cherenkov (A-RICH) counter,...

  14. acid modified silica: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    J. Cryan; John G. Rarity; Siyuan Yu; Jeremy L. O'Brien 2008-02-01 83 Hydrophobic silica aerogel production at KEK Nuclear Experiment (arXiv) Summary: We present herein a...

  15. Bioresponsive Mesoporous Silica Nanoparticles for Triggered Drug Release

    E-Print Network [OSTI]

    Singh, Neetu

    Mesoporous silica nanoparticles (MSNPs) have garnered a great deal of attention as potential carriers for therapeutic payloads. However, achieving triggered drug release from MSNPs in vivo has been challenging. Here, we ...

  16. Experimental evaluation of heat transfer characteristics of silica nanofluid

    E-Print Network [OSTI]

    Zhang, Zihao, S.B. Massachusetts Institute of Technology

    2010-01-01T23:59:59.000Z

    The laminar convective heat transfer characteristics were investigated for silica nanofluid. An experimental loop was built to obtain heat transfer coefficients for single-phase nanofluids in a circular conduit in laminar ...

  17. Adsorption of uranium on cross-linked amidoxime polymer from seawater

    SciTech Connect (OSTI)

    Hirotsu, T.; Katoh, S.; Sugasaka, K.; Takai, N.; Seno, M.; Itagaki, T.

    1987-10-01T23:59:59.000Z

    Adsorptive properties of uranium on cross-linked polymers bearing amidoxime groups from seawater were examined especially on the dependence upon hydrophilicity and porosity of the polymer. The hydrophilicity of the polymer was evaluated from heat of immersion in water. Proton-binding behavior of the polymer examined by the method of potentiometric titration revealed the existence of amidoxime groups as neutral species in seawater that seems to be responsible for a high adsorptivity of the amidoxime polymer toward uranium and principally determines the hydrophilic property. The adsorption rate of uranium on the polymers was significantly dependent on the product of the content of amidoxime groups and the surface area; furthermore, the polymers cross-linked with tetraethylene glycol dimethacrylate (4EGDM) exhibited a much higher adsorption rate than those with divinylbenzene.

  18. Augmenting a Microbial Selective Plugging Technique with Polymer Flooding to Increase the Efficiency of Oil Recovery - A Search for Synergy

    SciTech Connect (OSTI)

    Brown, Lewis R.; Pittman Jr., Charles U.; Lynch, F. Leo; Vadie, A. Alex; French, W. Todd

    2003-02-10T23:59:59.000Z

    The objective of this project was to determine if the effectiveness of a microbial permeability profile modification technique can be improved through polymer flooding.

  19. Silica Extraction at the Mammoth Lakes Geothermal Site

    SciTech Connect (OSTI)

    Bourcier, W; Ralph, W; Johnson, M; Bruton, C; Gutierrez, P

    2006-06-07T23:59:59.000Z

    The purpose of this project is to develop a cost-effective method to extract marketable silica (SiO{sub 2}) from fluids at the Mammoth Lakes, California geothermal power plant. Marketable silica provides an additional revenue source for the geothermal power industry and therefore lowers the costs of geothermal power production. The use of this type of ''solution mining'' to extract resources from geothermal fluids eliminates the need for acquiring these resources through energy intensive and environmentally damaging mining technologies. We have demonstrated that both precipitated and colloidal silica can be produced from the geothermal fluids at Mammoth Lakes by first concentrating the silica to over 600 ppm using reverse osmosis (RO). The RO permeate can be used in evaporative cooling at the plant; the RO concentrate is used for silica and potentially other (Li, Cs, Rb) resource extraction. Preliminary results suggest that silica recovery at Mammoth Lakes could reduce the cost of geothermal electricity production by 1.0 cents/kWh.

  20. SURFACTANT - POLYMER INTERACTION FOR IMPROVED OIL RECOVERY

    SciTech Connect (OSTI)

    Unknown

    1997-09-01T23:59:59.000Z

    The goal of this research is to use the interaction between a surfactant and a polymer for efficient displacement of tertiary oil by improving slug integrity, adsorption and mobility control. Surfactant--polymer flooding has been shown to be highly effective in laboratory-scale linear floods. The focus of this proposal is to design an inexpensive surfactant-polymer mixture that can efficiently recover tertiary oil by avoiding surfactant slug degradation, high adsorption and viscous/heterogeneity fingering. This report contains data concerning selection of appropriate fluids for use in laboratory experiments and numerical simulations. A mixture comprising a ''pseudo oil'' with appropriate surfactant and polymer is proposed. The properties of this system has been determined. The experimental set-up has been conditioned for use and experiments involving the aforementioned system have already started. A commercial simulator has been acquired for use in reproducing the experiments. A graduate student has been trained in its use. Linear stability analysis equations have been developed and phase maps for one and two-dimensions are currently computed.

  1. Gel polymer electrolytes for batteries

    DOE Patents [OSTI]

    Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William

    2014-11-18T23:59:59.000Z

    Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at 25.degree. C.

  2. Durable metallized polymer mirror

    DOE Patents [OSTI]

    Schissel, Paul O. (Golden, CO); Kennedy, Cheryl E. (Lafayette, CO); Jorgensen, Gary J. (Pine, CO); Shinton, Yvonne D. (Northglenn, CO); Goggin, Rita M. (Englewood, CO)

    1994-01-01T23:59:59.000Z

    A metallized polymer mirror construction having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate.

  3. POLYMER ELECTROLYTE FUEL CELLS

    E-Print Network [OSTI]

    Petta, Jason

    POLYMER ELECTROLYTE FUEL CELLS: The Gas Diffusion Layer Johannah Itescu Princeton University PRISM REU #12;PEM FUEL CELLS: A little background information I. What do fuel cells do? Generate electricity through chemical reaction #12;PEM FUEL CELLS: A little background information -+ + eHH 442 2 0244 22 He

  4. Solid polymer electrolyte compositions

    DOE Patents [OSTI]

    Garbe, James E. (Stillwater, MN); Atanasoski, Radoslav (Edina, MN); Hamrock, Steven J. (St. Paul, MN); Le, Dinh Ba (St. Paul, MN)

    2001-01-01T23:59:59.000Z

    An electrolyte composition is featured that includes a solid, ionically conductive polymer, organically modified oxide particles that include organic groups covalently bonded to the oxide particles, and an alkali metal salt. The electrolyte composition is free of lithiated zeolite. The invention also features cells that incorporate the electrolyte composition.

  5. Durable metallized polymer mirror

    DOE Patents [OSTI]

    Schissel, P.O.; Kennedy, C.E.; Jorgensen, G.J.; Shinton, Y.D.; Goggin, R.M.

    1994-11-01T23:59:59.000Z

    A metallized polymer mirror construction is disclosed having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate. 6 figs.

  6. Primordial polymer perturbations

    E-Print Network [OSTI]

    Sanjeev S. Seahra; Iain A. Brown; Golam Mortuza Hossain; Viqar Husain

    2012-09-25T23:59:59.000Z

    We study the generation of primordial fluctuations in pure de Sitter inflation where the quantum scalar field dynamics are governed by polymer (not Schrodinger) quantization. This quantization scheme is related to, but distinct from, the structures employed in Loop Quantum Gravity; and it modifies standard results above a polymer energy scale $M_{\\star}$. We recover the scale invariant Harrison Zel'dovich spectrum for modes that have wavelengths bigger than $M_{\\star}^{-1}$ at the start of inflation. The primordial spectrum for modes with initial wavelengths smaller than $M_{\\star}^{-1}$ exhibits oscillations superimposed on the standard result. The amplitude of these oscillations is proportional to the ratio of the inflationary Hubble parameter $H$ to the polymer energy scale. For reasonable choices of $M_{\\star}$, we find that polymer effects are likely unobservable in CMB angular power spectra due to cosmic variance uncertainty, but future probes of baryon acoustic oscillations may be able to directly constrain the ratio $H/M_{\\star}$.

  7. Mesoporous carbons and polymers

    DOE Patents [OSTI]

    Bell, William; Dietz, Steven

    2004-05-18T23:59:59.000Z

    A polymer is prepared by polymerizing a polymerizable component from a mixture containing the polymerizable component and a surfactant, the surfactant and the polymerizable component being present in the mixture in a molar ratio of at least 0.2:1, having an average pore size greater than 4 nm and a density greater than 0.1 g/cc. The polymerizable component can comprise a resorcinol/formaldehyde system and the mixture can comprise an aqueous solution or the polymerizable component can comprise a divinylbenzene/styrene system and the mixture can comprise an organic solution. Alternatively, the polymerizable component can comprise vinylidene chloride or a vinylidene chloride/divinylbenzene system. The polymer may be monolithic, have a BET surface area of at least about 50 m.sup.2 /g., include a quantity of at least one metal powder, or have an electrical conductivity greater than 10 Scm.sup.-1.

  8. Low band gap polymers Organic Photovoltaics

    E-Print Network [OSTI]

    Low band gap polymers for Organic Photovoltaics Eva Bundgaard Ph.D. Dissertation Risø National Bundgaard Title: Low band gap polymers for Organic photovoltaics Department: The polymer department Report the area of organic photovoltaics are focusing on low band gap polymers, a type of polymer which absorbs

  9. Solid polymer electrolytes

    DOE Patents [OSTI]

    Abraham, Kuzhikalail M. (Needham, MA); Alamgir, Mohamed (Dedham, MA); Choe, Hyoun S. (Waltham, MA)

    1995-01-01T23:59:59.000Z

    This invention relates to Li ion (Li.sup.+) conductive solid polymer electrolytes composed of poly(vinyl sulfone) and lithium salts, and their use in all-solid-state rechargeable lithium ion batteries. The lithium salts comprise low lattice energy lithium salts such as LiN(CF.sub.3 SO.sub.2).sub.2, LiAsF.sub.6, and LiClO.sub.4.

  10. Solid polymer electrolytes

    DOE Patents [OSTI]

    Abraham, K.M.; Alamgir, M.; Choe, H.S.

    1995-12-12T23:59:59.000Z

    This invention relates to Li ion (Li{sup +}) conductive solid polymer electrolytes composed of poly(vinyl sulfone) and lithium salts, and their use in all-solid-state rechargeable lithium ion batteries. The lithium salts comprise low lattice energy lithium salts such as LiN(CF{sub 3}SO{sub 2}){sub 2}, LiAsF{sub 6}, and LiClO{sub 4}. 2 figs.

  11. Polymer Stretching by Turbulence

    SciTech Connect (OSTI)

    Chertkov, Michael

    2000-05-15T23:59:59.000Z

    The stretching of a polymer chain by a large-scale chaotic flow is considered. The steady state which emerges as a balance of the turbulent stretching and anharmonic resistance of the chain is quantitatively described, i.e., the dependency on the flow parameters (Lyapunov exponent statistics) and the chain characteristics (the number of beads and the interbead elastic potential) is made explicit. (c) 2000 The American Physical Society.

  12. Polymer Crowding and Shape Distributions in Polymer-Nanoparticle Mixtures

    E-Print Network [OSTI]

    Wei Kang Lim; Alan R. Denton

    2014-10-24T23:59:59.000Z

    Macromolecular crowding can influence polymer shapes, which is important for understanding the thermodynamic stability of polymer solutions and the structure and function of biopolymers (proteins, RNA, DNA) under confinement. We explore the influence of nanoparticle crowding on polymer shapes via Monte Carlo simulations and free-volume theory of a coarse-grained model of polymer-nanoparticle mixtures. Exploiting the geometry of random walks, we model polymer coils as effective penetrable ellipsoids, whose shapes fluctuate according to the probability distributions of the eigenvalues of the gyration tensor. Accounting for the entropic cost of a nanoparticle penetrating a larger polymer coil, we compute the crowding-induced shift in the shape distributions, radius of gyration, and asphericity of ideal polymers in a theta solvent. With increased nanoparticle crowding, we find that polymers become more compact (smaller, more spherical), in agreement with predictions of free-volume theory. Our approach can be easily extended to nonideal polymers in good solvents and used to model conformations of biopolymers in crowded environments.

  13. Temperature and moisture dependence of dielectric constant for silica aerogels

    SciTech Connect (OSTI)

    Hrubesh, L.H., LLNL

    1997-03-01T23:59:59.000Z

    The dielectric constants of silica aerogels are among the lowest measured for any solid material. The silica aerogels also exhibit low thermal expansion and are thermally stable to temperatures exceeding 500{degrees}C. However, due to the open porosity and large surface areas for aerogels, their dielectric constants are strongly affected by moisture and temperature. This paper presents data for the dielectric constants of silica aerogels as a function of moisture content at 25{degrees}C, and as a function of temperature, for temperatures in the range from 25{degrees}C to 450{degrees}C. Dielectric constant data are also given for silica aerogels that are heat treated in dry nitrogen at 500{degrees}C, then cooled to 25{degrees}C for measurements in dry air. All measurements are made on bulk aerogel spheres at 22GHz microwave frequency, using a cavity perturbation method. The results of the dependence found here for bulk materials can be inferred to apply also to thin films of silica aerogels having similar nano-structures and densities.

  14. The Statistical Mechanics of Stretched Polymers

    E-Print Network [OSTI]

    Dmitry Ioffe; Yvan Velenik

    2009-08-04T23:59:59.000Z

    We describe some recent results concerning the statistical properties of a self-interacting polymer stretched by an external force. We concentrate mainly on the cases of purely attractive or purely repulsive self-interactions, but our results are stable under suitable small perturbations of these pure cases. We provide in particular a precise description of the stretched phase (local limit theorems for the end-point and local observables, invariance principle, microscopic structure). Our results also characterize precisely the (non-trivial, direction-dependent) critical force needed to trigger the collapsed/stretched phase transition in the attractive case. We also describe some recent progress: first, the determination of the order of the phase transition in the attractive case; second, a proof that a semi-directed polymer in quenched random environment is diffusive in dimensions 4 and higher when the temperature is high enough. In addition, we correct an incomplete argument from one of our earlier works.

  15. Large-area electrochromic coatings: Composites of polyaniline and polyacrylate-silica hybrid sol-gel materials

    SciTech Connect (OSTI)

    Jang, G.W.; Chen, C.; Gumbs, R.W. [Gumbs Associates, Inc., East Brunswick, NJ (United States); Wei, Y.; Yeh, J.M. [Drexel Univ., Philadelphia, PA (United States). Dept. of Chemistry

    1996-08-01T23:59:59.000Z

    A low-cost technique for fabricating large-area electrochromic coatings is described. Polyaniline was incorporated into polyacrylate-silica hybrid sol-gel networks using suspended particles or solutions. A solution of polyaniline and poly[methyl methacrylate-co-3-(trimethoxysilyl)propyl methacrylate] can be spray- or brush-coated on transparent indium-tin oxide substrates to form robust electrochromic coatings. Silane functional groups on the polyacrylate chain act as coupling and cross-linking agents to improve surface adhesion and mechanical properties of the resulting composite coatings. These coatings showed reversible transparent to green color change when polarized at potentials between {minus}0.4 and +0.4 V vs. Ag/AgCl in a 0.2 M LiClO{sub 4}/acetonitrile electrolyte solution. The cycle lifetimes of polyaniline films were improved by incorporating the polymer in the polyacrylate-silica matrix. Electrochromic switching was demonstrated for the composite coatings in large-area all-solid-state devices.

  16. Solid polymer electrolyte lithium batteries

    DOE Patents [OSTI]

    Alamgir, M.; Abraham, K.M.

    1993-10-12T23:59:59.000Z

    This invention pertains to Lithium batteries using Li ion (Li[sup +]) conductive solid polymer electrolytes composed of solvates of Li salts immobilized in a solid organic polymer matrix. In particular, this invention relates to Li batteries using solid polymer electrolytes derived by immobilizing solvates formed between a Li salt and an aprotic organic solvent (or mixture of such solvents) in poly(vinyl chloride). 3 figures.

  17. Solid polymer electrolyte lithium batteries

    DOE Patents [OSTI]

    Alamgir, Mohamed (Dedham, MA); Abraham, Kuzhikalail M. (Needham, MA)

    1993-01-01T23:59:59.000Z

    This invention pertains to Lithium batteries using Li ion (Li.sup.+) conductive solid polymer electrolytes composed of solvates of Li salts immobilized in a solid organic polymer matrix. In particular, this invention relates to Li batteries using solid polymer electrolytes derived by immobilizing solvates formed between a Li salt and an aprotic organic solvent (or mixture of such solvents) in poly(vinyl chloride).

  18. Incorporation of additives into polymers

    DOE Patents [OSTI]

    McCleskey, T. Mark; Yates, Matthew Z.

    2003-07-29T23:59:59.000Z

    There has been invented a method for incorporating additives into polymers comprising: (a) forming an aqueous or alcohol-based colloidal system of the polymer; (b) emulsifying the colloidal system with a compressed fluid; and (c) contacting the colloidal polymer with the additive in the presence of the compressed fluid. The colloidal polymer can be contacted with the additive by having the additive in the compressed fluid used for emulsification or by adding the additive to the colloidal system before or after emulsification with the compressed fluid. The invention process can be carried out either as a batch process or as a continuous on-line process.

  19. Stretched Polymers in Random Environment

    E-Print Network [OSTI]

    Dmitry Ioffe; Yvan Velenik

    2011-03-01T23:59:59.000Z

    We survey recent results and open questions on the ballistic phase of stretched polymers in both annealed and quenched random environments.

  20. Experimental Simulation of Evaporation-Driven Silica Sinter Formation and Microbial Silicification in Hot Spring Systems

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    in geothermal waters after they have reached the surface. Water evaporation is, along with cooling, one Evaporation of silica-rich geothermal waters is one of the main abiotic drivers of the formation of silica

  1. Surface modification of low density silica and bridged polysilsesquioxane aerogels

    SciTech Connect (OSTI)

    DeFriend, K. A. (Kimberly A.); Loy, D. A. (Douglas A.); Salazar, K. V. (Kenneth V.); Wilson, K. V. (Kennard V.)

    2004-01-01T23:59:59.000Z

    Silica and bridged polysilsesquioxane aerogels are low density materials that are attractive for applications such as, thermal insulation, porous separation media or catalyst supports, adsorbents. However, aerogels are notoriously weak and brittle making it difficult to handle and machine monoliths into desired forms. This prevents the development of many applications that would otherwise benefit from the use of the low density materials. We will describe our efforts to chemically modify and mechanically enhance silica-based aerogels using chemical vapor techniques without sacrificing their characteristic low densities. Monolithic silica and organically bridged polysilsesquioxane aerogels were prepared by sol-gel polymerization of the respective methoxysilane monomers followed by supercritical carbon dioxide drying of the gels. Reactive modification of the gels with volatile silylating compounds during and after the drying process and these effects on the mechanical properties and density of the aerogels will be described.

  2. PATCHY SILICA-COATED SILVER NANOWIRES AS SERS SUBSTRATES

    SciTech Connect (OSTI)

    Murph, S.; Murphy, C.

    2013-03-29T23:59:59.000Z

    We report a class of core-shell nanomaterials that can be used as efficient surface-enhancement Raman scattering (SERS) substrates. The core consists of silver nanowires, prepared through a chemical reduction process, that are used to capture 4- mercaptobenzoic acid (4-MBA), a model analyte. The shell was prepared through a modified Stöber method and consists of patchy or full silica coats. The formation of silica coats was monitored via transmission electron microscopy, UV-visible spectroscopy and phase-analysis light scattering for measuring effective surface charge. Surprisingly, the patchy silica coated silver nanowires are better SERS substrate than silver nanowires; nanomolar concentration of 4-MBA can be detected. In addition, “nano-matryoshka” configurations were used to quantitate/explore the effect of the electromagnetic field at the tips of the nanowire (“hot spots”) in the Raman scattering experiment.

  3. Thin film-coated polymer webs

    DOE Patents [OSTI]

    Wenz, Robert P. (Cottage Grove, MN); Weber, Michael F. (Shoreview, MN); Arudi, Ravindra L. (Woodbury, MN)

    1992-02-04T23:59:59.000Z

    The present invention relates to thin film-coated polymer webs, and more particularly to thin film electronic devices supported upon a polymer web, wherein the polymer web is treated with a purifying amount of electron beam radiation.

  4. Photopatterned conjugated polymer electrochromic nanofibers Arvind Kumara

    E-Print Network [OSTI]

    Otero, Toribio Fernández

    Photopatterned conjugated polymer electrochromic nanofibers on paper Arvind Kumara , Chris Asemotaa. Electrochromic nanofibers of conducting polymer (terthiophene) have been deposited over a conventional paper in electrochromic characters. SEM images of the conducting polymer nanofibers together with the cellulose fibers

  5. Nitinol-reinforced shape-memory polymers

    E-Print Network [OSTI]

    Di Leo, Claudio V

    2010-01-01T23:59:59.000Z

    Reinforced shape-memory polymers have been developed from an acrylate based thermoset shape-memory polymer and nitinol wires. A rectangular shape-memory polymer measuring approximately 1 by 2 by 0.1 inches has a ten fold ...

  6. Nanostructure Control of Biologically Inspired Polymers

    E-Print Network [OSTI]

    Rosales, Adrianne

    2013-01-01T23:59:59.000Z

    E. B. ; Wagener, K. B. Polymer 2008, 49, 2985-2995. Boz,T. ; Matyjaszewski, K. Polymer 2008, 49, 1567-1578. Kim,Flory, P. J. ; Jackson, J. B. Polymer 1963, 4, (2), 221-236.

  7. Stress-tuned conductor-polymer composite for use in sensors

    DOE Patents [OSTI]

    Martin, James E; Read, Douglas H

    2013-10-22T23:59:59.000Z

    A method for making a composite polymeric material with electrical conductivity determined by stress-tuning of the conductor-polymer composite, and sensors made with the stress-tuned conductor-polymer composite made by this method. Stress tuning is achieved by mixing a miscible liquid into the polymer precursor solution or by absorbing into the precursor solution a soluble compound from vapor in contact with the polymer precursor solution. The conductor may or may not be ordered by application of a magnetic field. The composite is formed by polymerization with the stress-tuning agent in the polymer matrix. The stress-tuning agent is removed following polymerization to produce a conductor-polymer composite with a stress field that depends on the amount of stress-tuning agent employed.

  8. Journal Title: Journal of polymer science. Part B, Polymer physics

    E-Print Network [OSTI]

    Fleming, Paul D. "Dan"

    composites. rigid rod polymer. mo- lecular modeling. poly (azomethine) · epoxy. glass/epoxy composite. Such composites would find * To whom correspondence should be addressed. Journal of Polymer Science: Part B molecular composite. Since heat conduction oc- curs more efficiently intramolecularly (through bonds) than

  9. Synthesis of highly ordered mesoporous silica materials using sodium silicate and amphiphilic block copolymers

    E-Print Network [OSTI]

    Kim, Ji Man

    Synthesis of highly ordered mesoporous silica materials using sodium silicate and amphiphilic block) structures, using sodium silicate as the silica source and amphiphilic block copolymers as the structure of mesoporous silica material using nonionic surfac- tant and sodium silicate in the pH range 3­10.5. However

  10. Hierarchical Silica Nanostructures Inspired by Diatom Algae Yield Superior Deformability, Toughness, and Strength

    E-Print Network [OSTI]

    Buehler, Markus J.

    Hierarchical Silica Nanostructures Inspired by Diatom Algae Yield Superior Deformability, Toughness algae that is mainly composed of amorphous silica, which features a hierarchical structure that ranges in diatom algae as a basis to study a bioinspired nanoporous material implemented in crystalline silica. We

  11. Analysis of the elastic behaviour of silica aerogels taken as a percolating system

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    289 Analysis of the elastic behaviour of silica aerogels taken as a percolating system T. Woignier of silica aerogels are performed using the three points flexural technique. The elastic behaviour is studied measurement - for silica aerogels. These highly porous materials are obtained from a sol-gel process. Solvent

  12. Multicomponent Transport of Sulfate in a Goethite-Silica Sand System

    E-Print Network [OSTI]

    Sparks, Donald L.

    Multicomponent Transport of Sulfate in a Goethite-Silica Sand System at Variable pH and Ionic of protons and sulfate on goethite and silica were used in combination with a one-dimensional mass-transport model to predict the transport of sulfate at variable pH and ionic strength in a goethite-silica system

  13. Singular Limits in Polymer Stabilized Liquid Crystals

    E-Print Network [OSTI]

    1910-31-00T23:59:59.000Z

    We investigate equilibrium configurations for a polymer stabilized liquid crys- tal material ... eling the cross section of the liquid crystal-polymer fiber composite.

  14. Partially fluorinated cyclic ionic polymers and membranes

    DOE Patents [OSTI]

    Yang, Zhen-Yu

    2013-04-09T23:59:59.000Z

    Ionic polymers are made from selected partially fluorinated dienes, in which the repeat units are cycloaliphatic. The polymers are formed into membranes.

  15. The effects of surface chemistry of mesoporous silica materials and solution pH on kinetics of molsidomine adsorption

    SciTech Connect (OSTI)

    Dolinina, E.S.; Parfenyuk, E.V., E-mail: terrakott37@mail.ru

    2014-01-15T23:59:59.000Z

    Adsorption kinetics of molsidomine on mesoporous silica material (UMS), the phenyl- (PhMS) and mercaptopropyl-functionalized (MMS) derivatives from solution with different pH and 298 K was studied. The adsorption kinetics was found to follow the pseudo-second-order kinetic model for all studied silica materials and pH. Effects of surface functional groups and pH on adsorption efficiency and kinetic adsorption parameters were investigated. At all studied pH, the highest molsidomine amount is adsorbed on PhMS due to ?–? interactions and hydrogen bonding between surface groups of PhMS and molsidomine molecules. An increase of pH results in a decrease of the amounts of adsorbed molsidomine onto the silica materials. Furthermore, the highest adsorption rate kinetically evaluated using a pseudo-second-order model, is observed onto UMS and it strongly depends on pH. The mechanism of the adsorption process was determined from the intraparticle diffusion and Boyd kinetic film–diffusion models. The results showed that the molsidomine adsorption on the silica materials is controlled by film diffusion. Effect of pH on the diffusion parameters is discussed. - Graphical abstract: The kinetic study showed that the k{sub 2} value, the rate constant of pseudo-second order kinetic model, is the highest for molsidomine adsorption on UMS and strongly depends on pH because it is determined by availability and accessibility of the reaction sites of the adsorbents molsidomine binding. Display Omitted - Highlights: • The adsorption capacities of UMS, PhMS and MMS were dependent on the pH. • At all studied pH, the highest molsidomine amount is adsorbed on PhMS. • The highest adsorption rate, k{sub 2}, is observed onto UMS and strongly depends on pH. • Film diffusion was the likely rate-limiting step in the adsorption process.

  16. Using Theory to Model Polymer Properties There are two general themes to this research: (1) polymer degradation that occurs when

    E-Print Network [OSTI]

    the polymer with nanoinclusions of carbon nanotubes and graphene sheets and other structures. Polymer

  17. Polymers in a vacuum

    E-Print Network [OSTI]

    J. M. Deutsch

    2007-06-13T23:59:59.000Z

    In a variety of situations, isolated polymer molecules are found in a vacuum and here we examine their properties. Angular momentum conservation is shown to significantly alter the average size of a chain and its conservation is only broken slowly by thermal radiation. The time autocorrelation for monomer position oscillates with a characteristic time proportional to chain length. The oscillations and damping are analyzed in detail. Short range repulsive interactions suppress oscillations and speed up relaxation but stretched chains still show damped oscillatory time correlations.

  18. Characterization of the molecular structure and mechanical properties of polymer surfaces and protein/polymer interfaces by sum frequency generation vibrational spectroscopy and atomic force microscopy

    SciTech Connect (OSTI)

    Koffas, Telly Stelianos

    2004-05-15T23:59:59.000Z

    Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and other complementary surface-sensitive techniques have been used to study the surface molecular structure and surface mechanical behavior of biologically-relevant polymer systems. SFG and AFM have emerged as powerful analytical tools to deduce structure/property relationships, in situ, for polymers at air, liquid and solid interfaces. The experiments described in this dissertation have been performed to understand how polymer surface properties are linked to polymer bulk composition, substrate hydrophobicity, changes in the ambient environment (e.g., humidity and temperature), or the adsorption of macromolecules. The correlation of spectroscopic and mechanical data by SFG and AFM can become a powerful methodology to study and engineer materials with tailored surface properties. The overarching theme of this research is the interrogation of systems of increasing structural complexity, which allows us to extend conclusions made on simpler model systems. We begin by systematically describing the surface molecular composition and mechanical properties of polymers, copolymers, and blends having simple linear architectures. Subsequent chapters focus on networked hydrogel materials used as soft contact lenses and the adsorption of protein and surfactant at the polymer/liquid interface. The power of SFG is immediately demonstrated in experiments which identify the chemical parameters that influence the molecular composition and ordering of a polymer chain's side groups at the polymer/air and polymer/liquid interfaces. In general, side groups with increasingly greater hydrophobic character will be more surface active in air. Larger side groups impose steric restrictions, thus they will tend to be more randomly ordered than smaller hydrophobic groups. If exposed to a hydrophilic environment, such as water, the polymer chain will attempt to orient more of its hydrophilic groups to the surface in order to minimize the total surface energy. With an understanding of the structural and environmental parameters which govern polymer surface structure, SFG is then used to explore the effects of surface hydrophobicity and solvent polarity on the orientation and ordering of amphiphilic neutral polymers adsorbed at the solid/liquid interface. SFG spectra show that poly(propylene glycol) (PPG) and poly(ethylene glycol) (PEG) adsorb with their hydrophobic moieties preferentially oriented toward hydrophobic polystyrene surfaces. These same moieties, however, disorder when adsorbed onto a hydrophilic silica/water interface. Water is identified as a critical factor for mediating the orientation and ordering of hydrophobic moieties in polymers adsorbed at hydrophobic interfaces. The role of bulk water content and water vapor, as they influence hydrogel surface structure and mechanics, continues to be explored in the next series of experiments. A method was developed to probe the surface viscoelastic properties of hydroxylethyl methacrylate (HEMA) based contact lens materials by analyzing AFM force-distance curves. AFM analysis indicates that the interfacial region is dehydrated, relative to the bulk. Experiments performed on poly(HEMA+MA) (MA = methacrylic acid), a more hydrophilic copolymer with greater bulk water content, show even greater water depletion at the surface. SFG spectra, as well as surface energy arguments, suggest that the more hydrophilic polymer component (such as MA) is not favored at the air interface; this may explain anomalies in water retention at the hydrogel surface. Adsorption of lysozyme onto poly(HEMA+MA) was found to further reduce near-surface viscous behavior, suggesting lower surface water content. Lastly, protein adsorption is studied using a model polymer system of polystyrene covalently bound with a monolayer of bovine serum albumin. SFG results indicate that some amino acid residues in proteins adopt preferred orientations. SFG spectra also show that the phenyl rings of the bare polystyrene substrate in contact with air or

  19. Vacuum flash evaporated polymer composites

    DOE Patents [OSTI]

    Affinito, John D. (Kennewick, WA); Gross, Mark E. (Pasco, WA)

    1997-01-01T23:59:59.000Z

    A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

  20. Vacuum flash evaporated polymer composites

    DOE Patents [OSTI]

    Affinito, J.D.; Gross, M.E.

    1997-10-28T23:59:59.000Z

    A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

  1. Self-extinguishing Polymer/Organoclay Nanocomposites

    SciTech Connect (OSTI)

    Si,M.; Zaitsev, V.; Goldman, M.; Frenkel, A.; Peiffer, D.; Weil, E.; Sokolov, J.; Rafailovich, M.

    2006-01-01T23:59:59.000Z

    We demonstrated that self-extinguishing polymer nanocomposites, which can pass the stringent UL 94 V0 standard, can be successfully prepared by combining modified organoclays with traditional flame retardant (FR) agents. Using secondary ion mass spectrometry (SIMS) and transmission electron microscopy (TEM), we determined that the addition of modified clays, which can intercalate or exfoliate in the matrix, also improved the dispersion of the FR agents. Dynamic mechanical analysis (DMA) indicated that the clays increased the modulus of the polymer above T{sub g}, which prevented dripping during burning. Cone calorimetry test showed that the nanocomposites with both FR and organoclay, had a lower peak heat release rate (PHRR) and average mass loss rate (MLR) than those with only clay or the FR agents. Extended X-ray absorption fine structure (EXAFS) data confirmed that no FR/clay interactions occurred in the solid phase, and that the synergistic effects were due to gas phase reactions. Since this mechanism is not specific, it opens the possibility of formulating self-extinguishing materials from a large class of polymers.

  2. Accelerated Characterization of Polymer Properties

    SciTech Connect (OSTI)

    R. Wroczynski; l. Brewer; D. Buckley; M. Burrell; R. Potyrailo

    2003-07-30T23:59:59.000Z

    This report describes the efforts to develop a suite of microanalysis techniques that can rapidly measure a variety of polymer properties of industrial importance, including thermal, photo-oxidative, and color stability; as well as ductility, viscosity, and mechanical and antistatic properties. Additional goals of the project were to direct the development of these techniques toward simultaneous measurements of multiple polymer samples of small size in real time using non-destructive and/or parallel or rapid sequential measurements, to develop microcompounding techniques for preparing polymers with additives, and to demonstrate that samples prepared in the microcompounder could be analyzed directly or used in rapid off-line measurements. These enabling technologies are the crucial precursors to the development of high-throughput screening (HTS) methodologies for the polymer additives industry whereby the rate of development of new additives and polymer formulations can be greatly accelerated.

  3. Rotational dynamics of entangled polymers

    E-Print Network [OSTI]

    Jean-Charles Walter; Michiel Laleman; Marco Baiesi; Enrico Carlon

    2014-09-01T23:59:59.000Z

    Some recent results on the rotational dynamics of polymers are reviewed and extended. We focus here on the relaxation of a polymer, either flexible or semiflexible, initially wrapped around a rigid rod. We also study the steady polymer rotation generated by a constant torque on the rod. The interplay of frictional and entropic forces leads to a complex dynamical behavior characterized by non-trivial universal exponents. The results are based on extensive simulations of polymers undergoing Rouse dynamics and on an analytical approach using force balance and scaling arguments. The analytical results are in general in good agreement with the simulations, showing how a simplified approach can correctly capture the complex dynamical behavior of rotating polymers.

  4. Oilfield flooding polymer

    DOE Patents [OSTI]

    Martin, Fred D. (Socorro, NM); Hatch, Melvin J. (Socorro, NM); Shepitka, Joel S. (Socorro, NM); Donaruma, Lorraine G. (Syosset, NY)

    1986-01-01T23:59:59.000Z

    A monomer, polymers containing the monomer, and the use of the polymer in oilfield flooding is disclosed. The subject monomer is represented by the general formula: ##STR1## wherein: n is an integer from 0 to about 4; m is an integer from 0 to about 6; a is an integer equal to at least 1 except where m is equal to 0, a must equal 0 and where m is equal to 1, a must equal 0 or 1; p is an integer from 2 to about 10; b is an integer equal to at least 1 and is of sufficient magnitude that the ratio b/p is at least 0.2; and q is an integer from 0 to 2. The number of hydroxy groups in the monomer is believed to be critical, and therefore the sum of (a+b) divided by the sum (m+p) should be at least 0.2. The moieties linked to the acrylic nitrogen can be joined to provide a ringed structure.

  5. Development of Silica/Vanadia/ Titania Catalysts for Removal of

    E-Print Network [OSTI]

    Li, Ying

    mercury (Hg0) from simulated coal-combustion flue gas. Experiments were carried out in fixed-bed reactorsDevelopment of Silica/Vanadia/ Titania Catalysts for Removal of Elemental Mercury from Coal-Combustion the composition and microstructures of SCR (selective catalytic reduction) catalysts for Hg0 oxidation in coal-combustion

  6. Silica dust control when drilling concrete Page 1 of 2

    E-Print Network [OSTI]

    Knowles, David William

    Silica dust control when drilling concrete Page 1 of 2 Drilling into concrete releases a fine sandy and routinely drill into concrete are at risk of developing this disease. Controlling the dust Hammer drills are available with attached dust removal systems. These draw dust from the drill end, down the attachment

  7. Fractal Studies on Titanium-Silica Aerogels using SMARTer

    SciTech Connect (OSTI)

    Putra, E. Giri Rachman; Ikram, A.; Bharoto; Santoso, E. [Neutron Scattering Laboratory, BATAN, Kawasan Puspiptek Serpong, Tangerang 15314 (Indonesia); Fang, T. Chiar; Ibrahim, N. [Department of Physics, Faculty of Science Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor (Malaysia); Mohamed, A. Aziz [Materials Technology Group, Industrial Technology Division Agensi Nuklear Malaysia, 43000 Kajang (Malaysia)

    2008-03-17T23:59:59.000Z

    Power-law scattering approximation has been employed to reveal the fractal structures of solid-state titanium-silica aerogel samples. All small-angle neutron scattering (SANS) measurements were performed using 36 meters SANS BATAN spectrometer (SMARTer) at the neutron scattering laboratory (NSL) in Serpong, Indonesia. The mass fractal dimension of titanium-silica aerogels at low scattering vector q range increases from -1.4 to -1.92 with the decrease of acid concentrations during sol-gel process. These results are attributed to the titanium-silica aerogels that are growing to more polymeric and branched structures. At high scattering vector q range the Porod slope of -3.9 significantly down to -2.24 as the roughness of particle surfaces becomes higher. The cross over between these two regimes decreases from 0.4 to 0.16 nm{sup -1} with the increase of acid concentrations indicating also that the titanium-silica aerogels are growing.

  8. Power scaling analysis of fiber lasers and amplifiers based on non-silica materials

    SciTech Connect (OSTI)

    Dawson, J W; Messerly, M J; Heebner, J E; Pax, P H; Sridharan, A K; Bullington, A L; Beach, R J; Siders, C W; Barty, C P; Dubinskii, M

    2010-03-30T23:59:59.000Z

    A developed formalism for analyzing the power scaling of diffraction limited fiber lasers and amplifiers is applied to a wider range of materials. Limits considered include thermal rupture, thermal lensing, melting of the core, stimulated Raman scattering, stimulated Brillouin scattering, optical damage, bend induced limits on core diameter and limits to coupling of pump diode light into the fiber. For conventional fiber lasers based upon silica, the single aperture, diffraction limited power limit was found to be 36.6kW. This is a hard upper limit that results from an interaction of the stimulated Raman scattering with thermal lensing. This result is dependent only upon physical constants of the material and is independent of the core diameter or fiber length. Other materials will have different results both in terms of ultimate power out and which of the many limits is the determining factor in the results. Materials considered include silica doped with Tm and Er, YAG and YAG based ceramics and Yb doped phosphate glass. Pros and cons of the various materials and their current state of development will be assessed. In particular the impact of excess background loss on laser efficiency is discussed.

  9. Dynamics of tungsten hexacarbonyl, dicobalt octacarbonyl, and their fragments adsorbed on silica surfaces

    SciTech Connect (OSTI)

    Muthukumar, Kaliappan; Valentí, Roser; Jeschke, Harald O. [Institut für Theoretische Physik, Goethe-Universität Frankfurt, Max-von-Laue-Straße 1, 60438 Frankfurt am Main (Germany)] [Institut für Theoretische Physik, Goethe-Universität Frankfurt, Max-von-Laue-Straße 1, 60438 Frankfurt am Main (Germany)

    2014-05-14T23:59:59.000Z

    Tungsten and cobalt carbonyls adsorbed on a substrate are typical starting points for the electron beam induced deposition of tungsten or cobalt based metallic nanostructures. We employ first principles molecular dynamics simulations to investigate the dynamics and vibrational spectra of W(CO){sub 6} and W(CO){sub 5} as well as Co{sub 2}(CO){sub 8} and Co(CO){sub 4} precursor molecules on fully and partially hydroxylated silica surfaces. Such surfaces resemble the initial conditions of electron beam induced growth processes. We find that both W(CO){sub 6} and Co{sub 2}(CO){sub 8} are stable at room temperature and mobile on a silica surface saturated with hydroxyl groups (OH), moving up to half an Angström per picosecond. In contrast, chemisorbed W(CO){sub 5} or Co(CO){sub 4} ions at room temperature do not change their binding site. These results contribute to gaining fundamental insight into how the molecules behave in the simulated time window of 20 ps and our determined vibrational spectra of all species provide signatures for experimentally distinguishing the form in which precursors cover a substrate.

  10. Design and optimization of polymer electrolyte membrane (PEM) fuel cells

    E-Print Network [OSTI]

    Grujicic, Mica

    Design and optimization of polymer electrolyte membrane (PEM) fuel cells M. Grujicic* , K optimization algorithm to determine an optimum design of the fuel cell with respect to the operation difference has the largest effect on the predicted polarization curve of the fuel cell. However, the optimal

  11. Flue gas injection control of silica in cooling towers.

    SciTech Connect (OSTI)

    Brady, Patrick Vane; Anderson, Howard L., Jr.; Altman, Susan Jeanne

    2011-06-01T23:59:59.000Z

    Injection of CO{sub 2}-laden flue gas can decrease the potential for silica and calcite scale formation in cooling tower blowdown by lowering solution pH to decrease equilibrium calcite solubility and kinetic rates of silica polymerization. Flue gas injection might best inhibit scale formation in power plant cooling towers that use impaired makeup waters - for example, groundwaters that contain relatively high levels of calcium, alkalinity, and silica. Groundwaters brought to the surface for cooling will degas CO{sub 2} and increase their pH by 1-2 units, possibly precipitating calcite in the process. Recarbonation with flue gas can lower the pHs of these fluids back to roughly their initial pH. Flue gas carbonation probably cannot lower pHs to much below pH 6 because the pHs of impaired waters, once outgassed at the surface, are likely to be relatively alkaline. Silica polymerization to form scale occurs most rapidly at pH {approx} 8.3 at 25 C; polymerization is slower at higher and lower pH. pH 7 fluids containing {approx}220 ppm SiO{sub 2} require > 180 hours equilibration to begin forming scale whereas at pH 8.3 scale formation is complete within 36 hours. Flue gas injection that lowers pHs to {approx} 7 should allow substantially higher concentration factors. Periodic cycling to lower recoveries - hence lower silica concentrations - might be required though. Higher concentration factors enabled by flue gas injection should decrease concentrate volumes and disposal costs by roughly half.

  12. Journal of Magnetism and Magnetic Materials 303 (2006) 163166 One-dimensional assemblies of silica-coated cobalt nanoparticles

    E-Print Network [OSTI]

    Entel, P.

    2006-01-01T23:59:59.000Z

    in revised form 28 October 2005 Available online 28 November 2005 Abstract Silica-coated cobalt nanoparticles for the formation process. Kobayashi et al. [3h] reported the synthesis of silica- coated cobalt nanoparticles which-defined silica shells. Varying the process led us to produce silica-coated chains of 32 nm cobalt nanoparticles

  13. Polymer solutions: from hard monomers to soft polymers

    E-Print Network [OSTI]

    J. -P. Hansen; C. I. Addison; A. A. Louis

    2005-07-15T23:59:59.000Z

    A coarse-graining strategy for dilute and semi-dilute solutions of interacting polymers, and of colloid polymer mixtures is briefly described. Monomer degrees of freedom are traced out to derive an effective, state dependent pair potential between the polymer centres of mass. The cross-over between good and poor solvent conditions is discussed within a scaling analysis. The method is extended to block copolymers represented as "necklaces" of soft "blobs", and its success is illustrated here in the case of a symmetric diblock copolymer which exhibits microphase separation.

  14. Polymer Thermodynamics and Chain Structure Polymers display some similarities and some differences with nano-aggregates.

    E-Print Network [OSTI]

    Beaucage, Gregory

    Polymer Thermodynamics and Chain Structure Polymers display some similarities and some differences with nano-aggregates. Both materials are composed of basic units, Kuhn units for polymers which are rod an aggregate in nanomaterials and a polymer coil in Polymer Science. The mass-fractal or minimum dimension

  15. Polymer adsorption near the surface of a polymer solution : a universal behaviour

    E-Print Network [OSTI]

    Boyer, Edmond

    699 Polymer adsorption near the surface of a polymer solution : a universal behaviour J. des5 , pour 0 03B5 1. Abstract.2014 A universal property of good solutions of long polymers near. Introduction. The free surface of a polymer solution may attract the polymer which forms an adsorbed layer

  16. ENG BE/ME/MS 504: Polymers and Soft Materials GRS PY 744: Polymer Physics.

    E-Print Network [OSTI]

    Vajda, Sandor

    ENG BE/ME/MS 504: Polymers and Soft Materials GRS PY 744: Polymer Physics. Prof. Rama Bansil Class will be assumed. The course will not emphasize synthetic polymer chemistry. Practical applications of polymers of classes TEXT BOOKS Main Text Book: Required: Polymer Chemistry, 2nd Edition, Hiemenz and Lodge, CRC Press

  17. Carbon nanotube-polymer composite actuators

    DOE Patents [OSTI]

    Gennett, Thomas (Denver, CO); Raffaelle, Ryne P. (Honeoye Falls, NY); Landi, Brian J. (Rochester, NY); Heben, Michael J. (Denver, CO)

    2008-04-22T23:59:59.000Z

    The present invention discloses a carbon nanotube (SWNT)-polymer composite actuator and method to make such actuator. A series of uniform composites was prepared by dispersing purified single wall nanotubes with varying weight percents into a polymer matrix, followed by solution casting. The resulting nanotube-polymer composite was then successfully used to form a nanotube polymer actuator.

  18. Kac polymers Paolo Butt`a

    E-Print Network [OSTI]

    Procacci, Aldo

    Kac polymers Paolo Butt`a Aldo Procacci Benedetto Scoppola Abstract We show how a polymer in two- sidered on the appropriate scale. Key words: Polymers, Kac potentials, phase transition. Running title: Kac polymers Dedicated to a Marzio Cassandro's birthday. 1 Introduction In the last two decades

  19. Non-strinking siloxane polymers

    DOE Patents [OSTI]

    Loy, Douglas A. (Albuquerque, NM); Rahimian, Kamyar (Albuquerque, NM)

    2001-01-01T23:59:59.000Z

    Cross-linked polymers formed by ring-opening polymerization of a precursor monomer of the general formula R[CH.sub.2 CH(Si(CH.sub.3).sub.2).sub.2 O].sub.2, where R is a phenyl group or an alkyl group having at least two carbon atoms. A cross-linked polymer is synthesized by mixing the monomer with a co-monomer of the general formula CH.sub.2 CHR.sup.2 (SiMe.sub.2).sub.2 O in the presence of an anionic base to form a cross-linked polymer of recurring units of the general formula R(Me.sub.2 SiOCH.sub.2 CHSiMe.sub.2).sub.2 [CH.sub.2 CHR.sup.2 (SiMe.sub.2).sub.2 O].sub.n, where R.sup.2 is hydrogen, phenyl, ethyl, propyl or butyl. If the precursor monomer is a liquid, the polymer can be directly synthesized in the presence of an anionic base to a cross-linked polymer containing recurring units of the general formula R(Me.sub.2 SiOCH.sub.2 CHSiMe.sub.2).sub.2. The polymers have approximately less than 1% porosity and are thermally stable at temperatures up to approximately 500.degree. C. The conversion to the cross-linked polymer occurs by ring opening polymerization and results in shrinkage of less than approximately 5% by volume.

  20. Thermodynamics of tubelike flexible polymers

    E-Print Network [OSTI]

    Thomas Vogel; Thomas Neuhaus; Michael Bachmann; Wolfhard Janke

    2009-07-17T23:59:59.000Z

    In this work we present the general phase behavior of short tubelike flexible polymers. The geometric thickness constraint is implemented through the concept of the global radius of curvature. We use sophisticated Monte Carlo sampling methods to simulate small bead-stick polymer models with Lennard-Jones interaction among non-bonded monomers. We analyze energetic fluctuations and structural quantities to classify conformational pseudophases. We find that the tube thickness influences the thermodynamic behavior of simple tubelike polymers significantly, i.e., for given temperature, the formation of secondary structures strongly depends on the tube thickness.

  1. Characterization of macro-length conducting polymers and the development of a conducting polymer rotary motor

    E-Print Network [OSTI]

    Schmid, Bryan D. (Bryan David), 1981-

    2005-01-01T23:59:59.000Z

    Conducting polymers are a subset of materials within the electroactive polymer class that exhibit active mechanical deformations. These deformations induce stresses and strains that allow for conducting polymers to be used ...

  2. Polymer electronic devices and materials.

    SciTech Connect (OSTI)

    Schubert, William Kent; Baca, Paul Martin; Dirk, Shawn M.; Anderson, G. Ronald; Wheeler, David Roger

    2006-01-01T23:59:59.000Z

    Polymer electronic devices and materials have vast potential for future microsystems and could have many advantages over conventional inorganic semiconductor based systems, including ease of manufacturing, cost, weight, flexibility, and the ability to integrate a wide variety of functions on a single platform. Starting materials and substrates are relatively inexpensive and amenable to mass manufacturing methods. This project attempted to plant the seeds for a new core competency in polymer electronics at Sandia National Laboratories. As part of this effort a wide variety of polymer components and devices, ranging from simple resistors to infrared sensitive devices, were fabricated and characterized. Ink jet printing capabilities were established. In addition to promising results on prototype devices the project highlighted the directions where future investments must be made to establish a viable polymer electronics competency.

  3. Continuous production of conducting polymer

    E-Print Network [OSTI]

    Gaige, Terry A. (Terry Alden), 1981-

    2004-01-01T23:59:59.000Z

    A device to continuously produce polypyrrole was designed, manufactured, and tested. Polypyrrole is a conducting polymer which has potential artificial muscle applications. The objective of continuous production was to ...

  4. Constitutive modeling of active polymers

    E-Print Network [OSTI]

    Therkelsen, Scott V. (Scott Vincent), 1980-

    2005-01-01T23:59:59.000Z

    This thesis develops a three-dimensional constitutive model of active polymeric materials, including changes in material volume and properties due to actuation. Active polymers reversibly change shape, volume and/or material ...

  5. A conjugated polymer plastic gel

    E-Print Network [OSTI]

    Alcazar Jorba, Daniel

    2008-01-01T23:59:59.000Z

    We present a gel route to process highly oriented conjugated polymer films and fibers. The incorporation of hexafluoroisopropanol, a strong and stable dipolar group, to the polythiophene backbone enhances the solubility ...

  6. Conductive polymer-based material

    DOE Patents [OSTI]

    McDonald, William F. (Utica, OH); Koren, Amy B. (Lansing, MI); Dourado, Sunil K. (Ann Arbor, MI); Dulebohn, Joel I. (Lansing, MI); Hanchar, Robert J. (Charlotte, MI)

    2007-04-17T23:59:59.000Z

    Disclosed are polymer-based coatings and materials comprising (i) a polymeric composition including a polymer having side chains along a backbone forming the polymer, at least two of the side chains being substituted with a heteroatom selected from oxygen, nitrogen, sulfur, and phosphorus and combinations thereof; and (ii) a plurality of metal species distributed within the polymer. At least a portion of the heteroatoms may form part of a chelation complex with some or all of the metal species. In many embodiments, the metal species are present in a sufficient concentration to provide a conductive material, e.g., as a conductive coating on a substrate. The conductive materials may be useful as the thin film conducting or semi-conducting layers in organic electronic devices such as organic electroluminescent devices and organic thin film transistors.

  7. High elastic modulus polymer electrolytes

    DOE Patents [OSTI]

    Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel

    2013-10-22T23:59:59.000Z

    A polymer that combines high ionic conductivity with the structural properties required for Li electrode stability is useful as a solid phase electrolyte for high energy density, high cycle life batteries that do not suffer from failures due to side reactions and dendrite growth on the Li electrodes, and other potential applications. The polymer electrolyte includes a linear block copolymer having a conductive linear polymer block with a molecular weight of at least 5000 Daltons, a structural linear polymer block with an elastic modulus in excess of 1.times.10.sup.7 Pa and an ionic conductivity of at least 1.times.10.sup.-5 Scm.sup.-1. The electrolyte is made under dry conditions to achieve the noted characteristics.

  8. Polyphosphazine-based polymer materials

    DOE Patents [OSTI]

    Fox, Robert V.; Avci, Recep; Groenewold, Gary S.

    2010-05-25T23:59:59.000Z

    Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

  9. Polymer Bose--Einstein Condensates

    E-Print Network [OSTI]

    E. Castellanos; G. Chacon-Acosta

    2013-01-22T23:59:59.000Z

    In this work we analyze a non--interacting one dimensional polymer Bose--Einstein condensate in an harmonic trap within the semiclassical approximation. We use an effective Hamiltonian coming from the polymer quantization that arises in loop quantum gravity. We calculate the number of particles in order to obtain the critical temperature. The Bose--Einstein functions are replaced by series, whose high order terms are related to powers of the polymer length. It is shown that the condensation temperature presents a shift respect to the standard case, for small values of the polymer scale. In typical experimental conditions, it is possible to establish a bound for $\\lambda^{2}$ up to $ \\lesssim 10 ^{-16}$m$^2$. To improve this bound we should decrease the frequency of the trap and also decrease the number of particles.

  10. Layered plasma polymer composite membranes

    DOE Patents [OSTI]

    Babcock, W.C.

    1994-10-11T23:59:59.000Z

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is [>=]2 and is the number of selective layers. 2 figs.

  11. Hydrogen-Bond Acidic Polymers for Chemical Vapor Sensing. | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Acidic Polymers for Chemical Vapor Sensing. Hydrogen-Bond Acidic Polymers for Chemical Vapor Sensing. Abstract: A review with 171 references. Hydrogen-bond acidic polymers for...

  12. Exploring Polymer and Liposomal Carriers for Optimized Drug Delivery

    E-Print Network [OSTI]

    Ferguson, Heidi M

    2012-01-01T23:59:59.000Z

    1459–1467. Fox, M. E. Dendritic polymers for the delivery ofiii Chapter 1: Introduction to Polymer and Liposome Drugbioavailability. Conclusions Polymers and liposomes can be

  13. Polymer-Ceramic MEMS Bimorphs as Thermal Infrared Sensors

    E-Print Network [OSTI]

    Warren, Clinton Gregory

    2010-01-01T23:59:59.000Z

    Recent Developments in Polymer MEMS. Advanced Materials,using thin silicon/polymer bimorph membranes. Sensors andof cantilever arrays reveal polymer film expansion and

  14. Vadose Zone Soil Moisture Wicking Using Super Absorbent Polymers...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Vadose Zone Soil Moisture Wicking Using Super Absorbent Polymers. Vadose Zone Soil Moisture Wicking Using Super Absorbent Polymers. Abstract: Super-absorbent polymers (SAPs) have...

  15. a-1 polymer chemistry: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    walk in random Sepplinen, Timo 16 Polymer-Metal Nanocomposites via Polymer Thin Film Computer Technologies and Information Sciences Websites Summary: Polymer-Metal...

  16. Coordination polymers and building blocks based on ditopic heteroscorpionate ligands

    E-Print Network [OSTI]

    Santillan, Guillermo A.

    2009-01-01T23:59:59.000Z

    of Silver (I) Coordination Polymers formed through hydrogenBlocks for Coordination Polymers” Inorg. Chem. *One of theof Silver(I) Coordination Polymers Formed through Hydrogen

  17. High cation transport polymer electrolyte

    DOE Patents [OSTI]

    Gerald, II, Rex E. (Brookfield, IL); Rathke, Jerome W. (Homer Glen, IL); Klingler, Robert J. (Westmont, IL)

    2007-06-05T23:59:59.000Z

    A solid state ion conducting electrolyte and a battery incorporating same. The electrolyte includes a polymer matrix with an alkali metal salt dissolved therein, the salt having an anion with a long or branched chain having not less than 5 carbon or silicon atoms therein. The polymer is preferably a polyether and the salt anion is preferably an alkyl or silyl moiety of from 5 to about 150 carbon/silicon atoms.

  18. A molecular dynamics investigation of the unusual concentration dependencies of Fick diffusivities in silica mesopores

    SciTech Connect (OSTI)

    Krishna, Rajamani; van Baten, Jasper M

    2011-01-01T23:59:59.000Z

    Molecular Dynamics (MD) simulations were carried out to determine the self-diffusivitiy, D{sub i,self}, the Maxwell–Stefan diffusivity, Ð{sub i}, and the Fick diffusivity, D{sub i}, for methane (C1), ethane (C2), propane (C3), n-butane (nC4), n-pentane (nC5), n-hexane (nC6), n-heptane (nC7), and cyclohexane (cC6) in cylindrical silica mesopores for a range of pore concentrations. The MD simulations show that zero-loading diffusivity Ð{sub i}(0) is consistently lower, by up to a factor of 20, than the values anticipated by the classical Knudsen formula. The concentration dependence of the Fick diffusivity, D{sub i} is found to be unusually complex, and displays a strong minimum in some cases; this characteristic can be traced to molecular clustering.

  19. Chemoradiotherapeutic wrinkled mesoporous silica nanoparticles for use in cancer therapy

    SciTech Connect (OSTI)

    Munaweera, Imalka; Balkus, Kenneth J. Jr., E-mail: Balkus@utdallas.edu, E-mail: Anthony.DiPasqua@unthsc.edu [Department of Chemistry, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080 (United States); Koneru, Bhuvaneswari; Shi, Yi; Di Pasqua, Anthony J., E-mail: Balkus@utdallas.edu, E-mail: Anthony.DiPasqua@unthsc.edu [Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, Texas 76107 (United States)

    2014-11-01T23:59:59.000Z

    Over the last decade, the development and application of nanotechnology in cancer detection, diagnosis, and therapy have been widely reported. Engineering of vehicles for the simultaneous delivery of chemo- and radiotherapeutics increases the effectiveness of the therapy and reduces the dosage of each individual drug required to produce an observable therapeutic response. We here developed a novel chemoradiotherapeutic 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid coated/uncoated platinum drug loaded, holmium-containing, wrinkled mesoporous silica nanoparticle. The materials were characterized with TEM, FTIR, {sup 1}H NMR, energy dispersive x-ray, inductively coupled plasma-mass spectrometry, and zeta potential measurements. In vitro platinum drug release from both lipid coated and uncoated chemoradiotherapeutic wrinkled mesoporous silica are reported. Various kinetic models were used to analyze the release kinetics. The radioactivity of the chemoradiotherapeutic nanocarriers was measured after neutron-activation.

  20. Molecular engineering of porous silica using aryl templates

    DOE Patents [OSTI]

    Loy, D.A.; Shea, K.J.

    1994-06-14T23:59:59.000Z

    A process is described for manipulating the porosity of silica using a series of organic template groups covalently incorporated into the silicate matrix. The templates in the bridged polysilsesquioxanes are selectively removed from the material by oxidation with oxygen plasma or other means, leaving engineered voids or pores. The size of these pores is dependent upon the length or size of the template or spacer. The size of the templates is measured in terms of Si-Si distances which range from about 0.67 nm to 1.08 nm. Changes introduced by the loss of the templates result in a narrow range of micropores (i.e. <2 nm). Both aryl and alkyl template groups are used as spacers. Novel microporous silica materials useful as molecular sieves, desiccants, and catalyst supports are produced. 3 figs.

  1. Molecular engineering of porous silica using aryl templates

    DOE Patents [OSTI]

    Loy, Douglas A. (Albuquerque, NM); Shea, Kenneth J. (Irvine, CA)

    1994-01-01T23:59:59.000Z

    A process for manipulating the porosity of silica using a series of organic template groups covalently incorporated into the silicate matrix. The templates in the bridged polysilsesquioxanes are selectively removed from the material by oxidation with oxygen plasma or other means, leaving engineered voids or pores. The size of these pores is dependent upon the length or size of the template or spacer. The size of the templates is measured in terms of Si-Si distances which range from about 0.67 nm to 1.08 nm. Changes introduced by the loss of the templates result in a narrow range of micropores (i.e. <2 nm). Both aryl and alkyl template groups are used as spacers. Novel microporous silica materials useful as molecular seives, dessicants, and catalyst supports are produced.

  2. Silica aerogels modified by functional and nonfunctional organic groups

    SciTech Connect (OSTI)

    Schubert, U.; Huesing, N.; Schwertfeger, F. [Universitaet Wien (Austria)

    1996-12-31T23:59:59.000Z

    Organically substituted silica aerogels were prepared from RSi(OR`){sub 3}/Si(OR`){sub 4} mixtures, followed by supercritical drying. The typical microstructure and the resulting physical properties of silica aerogels are retained, if the portion of R-Si units is below 10-20%. However, new properties are supplemented, such as hydrophobicity (which makes the aerogels insensitive towards moisture), a higher compliance, and the possibility to incorporate functional organic groups. Controlled pyrolysis of the organically substituted aerogels allows to coat the inner surface of the aerogels with nanometer-sized carbon structures. This results in a very efficient infrared opacification and improved heat insulation properties at high temperatures. 5 refs., 2 figs.

  3. Process for manufacturing hollow fused-silica insulator cylinder

    DOE Patents [OSTI]

    Sampayan, Stephen E. (Manteca, CA); Krogh, Michael L. (Lee's Summit, MO); Davis, Steven C. (Lee's Summit, MO); Decker, Derek E. (Discovery Bay, CA); Rosenblum, Ben Z. (Overland Park, KS); Sanders, David M. (Livermore, CA); Elizondo-Decanini, Juan M. (Albuquerque, NM)

    2001-01-01T23:59:59.000Z

    A method for building hollow insulator cylinders that can have each end closed off with a high voltage electrode to contain a vacuum. A series of fused-silica round flat plates are fabricated with a large central hole and equal inside and outside diameters. The thickness of each is related to the electron orbit diameter of electrons that escape the material surface, loop, and return back. Electrons in such electron orbits can support avalanche mechanisms that result in surface flashover. For example, the thickness of each of the fused-silica round flat plates is about 0.5 millimeter. In general, the thinner the better. Metal, such as gold, is deposited onto each top and bottom surface of the fused-silica round flat plates using chemical vapor deposition (CVD). Eutectic metals can also be used with one alloy constituent on the top and the other on the bottom. The CVD, or a separate diffusion step, can be used to defuse the deposited metal deep into each fused-silica round flat plate. The conductive layer may also be applied by ion implantation or gas diffusion into the surface. The resulting structure may then be fused together into an insulator stack. The coated plates are aligned and then stacked, head-to-toe. Such stack is heated and pressed together enough to cause the metal interfaces to fuse, e.g., by welding, brazing or eutectic bonding. Such fusing is preferably complete enough to maintain a vacuum within the inner core of the assembled structure. A hollow cylinder structure results that can be used as a core liner in a dielectric wall accelerator and as a vacuum envelope for a vacuum tube device where the voltage gradients exceed 150 kV/cm.

  4. Nanostructured polymer membranes for proton conduction

    DOE Patents [OSTI]

    Balsara, Nitash Pervez; Park, Moon Jeong

    2013-06-18T23:59:59.000Z

    Polymers having an improved ability to entrain water are characterized, in some embodiments, by unusual humidity-induced phase transitions. The described polymers (e.g., hydrophilically functionalized block copolymers) have a disordered state and one or more ordered states (e.g., a lamellar state, a gyroid state, etc.). In one aspect, the polymers are capable of undergoing a disorder-to-order transition while the polymer is exposed to an increasing temperature at a constant relative humidity. In some aspects the polymer includes a plurality of portions, wherein a first portion forms proton-conductive channels within the membrane and wherein the channels have a width of less than about 6 nm. The described polymers are capable of entraining and preserving water at high temperature and low humidity. Surprisingly, in some embodiments, the polymers are capable of entraining greater amounts of water with the increase of temperature. The polymers can be used in Polymer Electrolyte Membranes in fuel cells.

  5. Silica aerogel: An intrinsically low dielectric constant material

    SciTech Connect (OSTI)

    Hrubesh, L.W.

    1995-04-01T23:59:59.000Z

    Silica aerogels are highly porous solids having unique morphologies in wavelength of visible which both the pores and particles have sizes less than the wavelength of visible light. This fine nanostructure modifies the normal transport mechanisms within aerogels and endows them with a variety of exceptional physical properties. For example, aerogels have the lowest measured thermal conductivity and dielectric constant for any solid material. The intrinsically low dielectric properties of silica aerogels are the direct result of the extremely high achievable porosities, which are controllable over a range from 75% to more than 99.8 %, and which result in measured dielectric constants from 2.0 to less than 1.01. This paper discusses the synthesis of silica aerogels, processing them as thin films, and characterizing their dielectric properties. Existing data and other physical characteristics of bulk aerogels (e.g., thermal stablity, thermal expansion, moisture adsorption, modulus, dielectric strength, etc.), which are useful for evaluating them as potential dielectrics for microelectronics, are also given.

  6. Measurement of Radiation Damage on Silica Aerogel Cerenkov Radiator

    E-Print Network [OSTI]

    Belle Preprint; Sahu Wang; M. Z. Wang; R. Suda; R. Enomoto; K. C. Peng; C. H. Wang; I. Adachi; M. Amami

    We measured the radiation damage on silica aerogel Cerenkov radiators originally developed for the B-factory experiment at KEK. Refractive index of the aerogel samples ranged from 1.012 to 1.028. The samples were irradiated up to 9.8 MRad of equivalent dose. Measurements of transmittance and refractive index were carried out and these samples were found to be radiation hard. Deteriorations in transparency and changes of refractive index were observed to be less than 1.3% and 0.001 at 90% confidence level, respectively. Prospects of using aerogels under high-radiation environment are discussed. 1 Introduction Silica aerogels(aerogels) are a colloidal form of glass, in which globules of silica are connected in three dimensional networks with siloxan bonds. They are solid, very light, transparent and their refractive index can be controlled in the production process. Many high energy and nuclear physics experiments have used aerogels instead of pressurized gas for their Cerenkov coun...

  7. Polymer Parametrised Field Theory

    E-Print Network [OSTI]

    Alok Laddha; Madhavan Varadarajan

    2008-05-02T23:59:59.000Z

    Free scalar field theory on 2 dimensional flat spacetime, cast in diffeomorphism invariant guise by treating the inertial coordinates of the spacetime as dynamical variables, is quantized using LQG type `polymer' representations for the matter field and the inertial variables. The quantum constraints are solved via group averaging techniques and, analogous to the case of spatial geometry in LQG, the smooth (flat) spacetime geometry is replaced by a discrete quantum structure. An overcomplete set of Dirac observables, consisting of (a) (exponentials of) the standard free scalar field creation- annihilation modes and (b) canonical transformations corresponding to conformal isometries, are represented as operators on the physical Hilbert space. None of these constructions suffer from any of the `triangulation' dependent choices which arise in treatments of LQG. In contrast to the standard Fock quantization, the non- Fock nature of the representation ensures that the algebra of conformal isometries as well as that of spacetime diffeomorphisms are represented in an anomaly free manner. Semiclassical states can be analysed at the gauge invariant level. It is shown that `physical weaves' necessarily underly such states and that such states display semiclassicality with respect to, at most, a countable subset of the (uncountably large) set of observables of type (a). The model thus offers a fertile testing ground for proposed definitions of quantum dynamics as well as semiclassical states in LQG.

  8. SUPER HARD SURFACED POLYMERS

    SciTech Connect (OSTI)

    Mansur, Louis K [ORNL] [ORNL; Bhattacharya, R [UES, Incorporated, Dayton, OH] [UES, Incorporated, Dayton, OH; Blau, Peter Julian [ORNL] [ORNL; Clemons, Art [ORNL] [ORNL; Eberle, Cliff [ORNL] [ORNL; Evans, H B [UES, Incorporated, Dayton, OH] [UES, Incorporated, Dayton, OH; Janke, Christopher James [ORNL] [ORNL; Jolly, Brian C [ORNL] [ORNL; Lee, E H [Consultant, Milpitas, CA] [Consultant, Milpitas, CA; Leonard, Keith J [ORNL] [ORNL; Trejo, Rosa M [ORNL] [ORNL; Rivard, John D [ORNL] [ORNL

    2010-01-01T23:59:59.000Z

    High energy ion beam surface treatments were applied to a selected group of polymers. Of the six materials in the present study, four were thermoplastics (polycarbonate, polyethylene, polyethylene terephthalate, and polystyrene) and two were thermosets (epoxy and polyimide). The particular epoxy evaluated in this work is one of the resins used in formulating fiber reinforced composites for military helicopter blades. Measures of mechanical properties of the near surface regions were obtained by nanoindentation hardness and pin on disk wear. Attempts were also made to measure erosion resistance by particle impact. All materials were hardness tested. Pristine materials were very soft, having values in the range of approximately 0.1 to 0.5 GPa. Ion beam treatment increased hardness by up to 50 times compared to untreated materials. For reference, all materials were hardened to values higher than those typical of stainless steels. Wear tests were carried out on three of the materials, PET, PI and epoxy. On the ion beam treated epoxy no wear could be detected, whereas the untreated material showed significant wear.

  9. A novel reactive processing technique: using telechelic polymers to reactively compatibilize polymer blends

    SciTech Connect (OSTI)

    Ashcraft, Earl C [ORNL; Ji, Haining [ORNL; Mays, Jimmy [ORNL; Dadmun, Mark D [ORNL

    2009-01-01T23:59:59.000Z

    Difunctional reactive polymers, telechelics, were used to reactively form multiblock copolymers in situ when melt-blended with a blend of polystyrene and polyisoprene. To quantify the ability of the copolymer to compatibilize the blends, the time evolution of the domain size upon annealing was analyzed by SEM. It was found that the most effective parameter to quantify the ability of the copolymer to inhibit droplet coalescence is Kreltstable, the relative coarsening constant multiplied by the stabilization time. These results indicate that intermediate-molecular-weight telechelic pairs of both highly reactive Anhydride-PS-Anhydride/NH2-PI-NH2 and slower reacting Epoxy-PS-Epoxy/COOH-PI-COOH both effectively suppress coalescence, with the optimal molecular weight being slightly above the critical molecular weight of the homopolymer,Mc. The effects of telechelic loading were also investigated, where the optimal loading concentration for this system was 0.5 wt %, as higher concentrations exhibited a plasticizing effect due to the presence of unreacted low-molecular-weight telechelics present in the blend. A determination of the interfacial coverage of the copolymer shows that a conversion of 1.5-3.0% was required for 20% surface coverage at 5.0 wt % telechelic loading, indicating a large excess of telechelics in this system. At the optimal loading level of 0.5 wt %, a conversion of 15% was required for 20% surface coverage. The results of these experiments provide a clear understanding of the role of telechelic loading and molecular weight on its ability to reactively form interfacial modifiers in phase-separated polymer blends and provide guidelines for the development of similar reactive processing schemes that can use telechelic polymers to reactively compatibilize a broad range of polymer blends.

  10. Nanowires and Nanostructures That Grow Like Polymer Molecules

    SciTech Connect (OSTI)

    Shaw, Santosh [Iowa State University; Cademartiri, Ludovico [Ames Laboratory

    2013-09-20T23:59:59.000Z

    Unique properties (e.g., rubber elasticity, viscoelasticity, folding, reptation) determine the utility of polymer molecules and derive from their morphology (i.e., one-dimensional connectivity and large aspect ratios) and flexibility. Crystals do not display similar properties because they have smaller aspect ratios, they are rigid, and they are often too large and heavy to be colloidally stable. We argue, with the support of recent experimental studies, that these limitations are not fundamental and that they might be overcome by growth processes that mimic polymerization. Furthermore, we (i) discuss the similarities between crystallization and polymerization, (ii) critically review the existing experimental evidence of polymer-like growth kinetic and behavior in crystals and nanostructures, and (iii) propose heuristic guidelines for the synthesis of “polymer-like” crystals and assemblies. Understanding these anisotropic materials at the boundary between molecules and solids will determine whether we can confer the unique properties of polymer molecules to crystals, expanding them with topology, dynamics, and information and not just tuning them with size.

  11. Spatial correlation between chemical and topological defects in vitreous silica: UV-resonance Raman study

    SciTech Connect (OSTI)

    Saito, M., E-mail: makina.saito@elettra.eu; D’Amico, F.; Bencivenga, F.; Cucini, R.; Gessini, A.; Principi, E.; Masciovecchio, C. [Elettra-Sincrotrone Trieste, S. S. 14 Km 163.5, I-34149 Trieste (Italy)

    2014-06-28T23:59:59.000Z

    A spatial correlation between chemical and topological defects in the tetrahedron network in vitreous silica produced by a fusion process of natural quartz crystals was found by synchrotron-based UV resonance Raman experiments. Furthermore, a quantitative correlation between these defects was obtained by comparing visible Raman and UV absorption spectra. These results indicate that in vitreous silica produced by the fusion process the topological defects disturb the surrounding tetrahedral silica network and induce further disorder regions with sub nanometric sizes.

  12. Synthesis of Mesocellular Silica Foams with Tunable Window and Cell Dimensions

    E-Print Network [OSTI]

    Yang, Peidong

    Polystyrene microspheres coated with cationic surfactants are easily prepared by micro- emulsion templates. These silica foams resemble dense aerogels. Introduction Because of their greatly enhanced pore

  13. Biotransformation of Two-Line Silica-Ferrihydrite by a Dissimilatory...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    by a Dissimilatory Fe(III)-Reducing Bacterium: Formation of Carbonate Green Biotransformation of Two-Line Silica-Ferrihydrite by a Dissimilatory Fe(III)-Reducing...

  14. TESLA-FEL 2004-01 Silica Aerogel Radiators for Bunch Length Measurements ?

    E-Print Network [OSTI]

    J. Bähr A; V. Djordjadze A; D. Lipka A; A. Onuchin B; F. Stephan A

    Cherenkov radiators based on Silica aerogel are used to measure the electron bunch length at the photo injector test facility at DESY Zeuthen (PITZ). The energy range of those electrons is 4-5 MeV. In this paper the time resolution defined by the usage of aerogel is calculated analytically and Monte Carlo simulations are performed. It is shown that Silica aerogel gives the possibility to reach a time resolution of about 0.1 ps for high photon intensities and a time resolution of about 0.02 ps can be obtained for thin Silica aerogel radiators. Key words: silica aerogel, bunch length, time resolution, PITZ 1

  15. Polymer Welding: Strength Through Entanglements

    E-Print Network [OSTI]

    Ting Ge; Flint Pierce; Dvora Perahia; Gary S. Grest; Mark O. Robbins

    2012-11-29T23:59:59.000Z

    Large-scale simulations of thermal welding of polymers are performed to investigate the rise of mechanical strength at the polymer-polymer interface with the welding time. The welding process is in the core of integrating polymeric elements into devices as well as in thermal induced healing of polymers; processes that require development of interfacial strength equal to that of the bulk. Our simulations show that the interfacial strength saturates at the bulk shear strength much before polymers diffuse by their radius of gyration. Along with the strength increase, the dominant failure mode changes from chain pullout at the interface to chain scission as in the bulk. Formation of sufficient entanglements across the interface, which we track using a Primitive Path Analysis is required to arrest catastrophic chain pullout at the interface. The bulk response is not fully recovered until the density of entanglements at the interface reaches the bulk value. Moreover, the increase of interfacial strength before saturation is proportional to the number of interfacial entanglements between chains from opposite sides.

  16. Solid-polymer-electrolyte fuel cells

    SciTech Connect (OSTI)

    Fuller, T.F.

    1992-07-01T23:59:59.000Z

    A transport model for polymer electrolytes is presented, based on concentrated solution theory and irreversible thermodynamics. Thermodynamic driving forces are developed, transport properties are identified and experiments devised. Transport number of water in Nafion 117 membrane is determined using a concentration cell. It is 1.4 for a membrane equilibrated with saturated water vapor at 25{degrees}C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the water content approaches zero. The relation between transference number, transport number, and electroosmotic drag coefficient is presented, and their relevance to water-management is discussed. A mathematical model of transport in a solid-polymer-electrolyte fuel cell is presented. A two-dimensional membrane-electrode assembly is considered. Water management, thermal management, and utilization of fuel are examined in detail. The membrane separators of these fuel cells require sorbed water to maintain conductivity; therefore it is necessary to manage the water content in membranes to ensure efficient operation. Water and thermal management are interrelated. Rate of heat removal is shown to be a critical parameter in the operation of these fuel cells. Current-voltage curves are presented for operation on air and reformed methanol. Equations for convective diffusion to a rotating disk are solved numerically for a consolute point between the bulk concentration and the surface. A singular-perturbation expansion is presented for the condition where the bulk concentration is nearly equal to the consolute-point composition. Results are compared to Levich's solution and analysis.

  17. Elastic and Viscoelastic Properties of Non-bulk Polymer Interphases in Nanotube-reinforced Polymers

    E-Print Network [OSTI]

    Fisher, Frank

    Elastic and Viscoelastic Properties of Non-bulk Polymer Interphases in Nanotube-reinforced Polymers polymer composite materials with outstanding mechanical, electrical, and thermal properties. A hurdle to nanoscale interactions between the embedded NTs and adjacent polymer chains. This interphase region

  18. ENG BE/ME/MS 504: Polymers and Soft Materials GRS PY 744: Polymer Physics.

    E-Print Network [OSTI]

    Vajda, Sandor

    ENG BE/ME/MS 504: Polymers and Soft Materials GRS PY 744: Polymer Physics. Prof. Rama Bansil Class: Blackboard.bu.edu ME/MS/BE 504 PY 744 A1 POLYMERS AND SOFT MATERIALS (FALL 2012) (12FALLENGME504_A1) E with thermodynamics and statistical mechanics will be assumed. Practical applications of polymers will be discussed

  19. Polymers: Molecular Structure [A polymer is a very large molecule comprising hundreds or thousands of atoms,

    E-Print Network [OSTI]

    Hall, Christopher

    1 Polymers: Molecular Structure [A polymer is a very large molecule comprising hundreds into chain or network structures|The concept of the polymer is one of the great ideas of twentieth century with the name of Hermann Staudinger who received the Nobel Prize in 1953. The influence of the polymer (or

  20. Confining multiple polymers between sticky walls: a directed walk model of two polymers

    E-Print Network [OSTI]

    Rechnitzer, Andrew

    Confining multiple polymers between sticky walls: a directed walk model of two polymers Thomas Wong 30, 2014 Abstract We study a model of two polymers confined to a slit with sticky walls. More on the square lattice. We compare the infinite slit limit, in which the length of the polymer (thermodynamic

  1. Process to produce lithium-polymer batteries

    DOE Patents [OSTI]

    MacFadden, Kenneth Orville (Highland, MD)

    1998-01-01T23:59:59.000Z

    A polymer bonded sheet product suitable for use as an electrode in a non-aqueous battery system. A porous electrode sheet is impregnated with a solid polymer electrolyte, so as to diffuse into the pores of the electrode. The composite is allowed to cool, and the electrolyte is entrapped in the porous electrode. The sheet products composed have the solid polymer electrolyte composition diffused into the active electrode material by melt-application of the solid polymer electrolyte composition into the porous electrode material sheet. The solid polymer electrolyte is maintained at a temperature that allows for rapid diffusion into the pores of the electrode. The composite electrolyte-electrode sheets are formed on current collectors and can be coated with solid polymer electrolyte prior to battery assembly. The interface between the solid polymer electrolyte composite electrodes and the solid polymer electrolyte coating has low resistance.

  2. The challenges of organic polymer solar cells

    E-Print Network [OSTI]

    Saif Addin, Burhan K. (Burhan Khalid)

    2011-01-01T23:59:59.000Z

    The technical and commercial prospects of polymer solar cells were evaluated. Polymer solar cells are an attractive approach to fabricate and deploy roll-to-roll processed solar cells that are reasonably efficient (total ...

  3. Modeling and Optimization of Interpenetrating Polymer

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    Modeling and Optimization of Interpenetrating Polymer Network Process Weijie Lin, Lorenz T. Biegler. Crosslinking Features Complex diffusion; single component reaction Complex composite networking reaction · Initiator feeding rate · Initial polymer · Monomer concentration · Initiator concentration · Holding

  4. Process to produce lithium-polymer batteries

    DOE Patents [OSTI]

    MacFadden, K.O.

    1998-06-30T23:59:59.000Z

    A polymer bonded sheet product is described suitable for use as an electrode in a non-aqueous battery system. A porous electrode sheet is impregnated with a solid polymer electrolyte, so as to diffuse into the pores of the electrode. The composite is allowed to cool, and the electrolyte is entrapped in the porous electrode. The sheet products composed have the solid polymer electrolyte composition diffused into the active electrode material by melt-application of the solid polymer electrolyte composition into the porous electrode material sheet. The solid polymer electrolyte is maintained at a temperature that allows for rapid diffusion into the pores of the electrode. The composite electrolyte-electrode sheets are formed on current collectors and can be coated with solid polymer electrolyte prior to battery assembly. The interface between the solid polymer electrolyte composite electrodes and the solid polymer electrolyte coating has low resistance. 1 fig.

  5. Transports of Polymer Nanomedicine in the Environment

    E-Print Network [OSTI]

    Zhang, Ming

    2013-11-14T23:59:59.000Z

    With increasing production and commercial use of polymer nanomedicine and a lack of regulation to govern their disposal, polymer nanomedicine may enter into soils and ultimately into ground water system. In this dissertation, adsorption of polymeric...

  6. Highly cross-linked nanoporous polymers

    DOE Patents [OSTI]

    Steckle, Jr., Warren P. (Los Alamos, NM); Apen, Paul G. (Los Alamos, NM); Mitchell, Michael A. (Los Alamos, NM)

    1998-01-01T23:59:59.000Z

    Condensation polymerization followed by a supercritical extraction step can be used to obtain highly cross-linked nanoporous polymers with high surface area, controlled pore sizes and rigid structural integrity. The invention polymers are useful for applications requiring separation membranes.

  7. Dynamics of Polymers in Flowing Colloidal Suspensions

    E-Print Network [OSTI]

    Chen, Hsieh

    Using hydrodynamic simulations we examine the behavior of single polymers in a confined colloidal suspension under flow. We study the conformations of both, collapsed and noncollapsed polymers. Our results show that the ...

  8. Highly cross-linked nanoporous polymers

    DOE Patents [OSTI]

    Steckle, Jr., Warren P. (Los Alamos, NM); Apen, Paul G. (Los Alamos, NM); Mitchell, Michael A. (Los Alamos, NM)

    1997-01-01T23:59:59.000Z

    Condensation polymerization followed by a supercritical extraction step can be used to obtain highly cross-linked nanoporous polymers with high surface area, controlled pore sizes and rigid structural integrity. The invention polymers are useful for applications requiring separation membranes.

  9. Post polymerization cure shape memory polymers

    SciTech Connect (OSTI)

    Wilson, Thomas S; Hearon, Michael Keith; Bearinger, Jane P

    2014-11-11T23:59:59.000Z

    This invention relates to chemical polymer compositions, methods of synthesis, and fabrication methods for devices regarding polymers capable of displaying shape memory behavior (SMPs) and which can first be polymerized to a linear or branched polymeric structure, having thermoplastic properties, subsequently processed into a device through processes typical of polymer melts, solutions, and dispersions and then crossed linked to a shape memory thermoset polymer retaining the processed shape.

  10. Adsorption of polymers at nanowires

    E-Print Network [OSTI]

    Thomas Vogel; Michael Bachmann

    2011-03-09T23:59:59.000Z

    Low-energy structures of a hybrid system consisting of a polymer and an attractive nanowire substrate as well as the thermodynamics of the adsorption transition are studied by means of Monte Carlo computer simulations. Depending on structural and energetic properties of the substrate, we find different adsorbed polymer conformations, amongst which are spherical droplets attached to the wire and monolayer tubes surrounding it. We identify adsorption temperatures and the type of the transition between adsorbed and desorbed structures depending on the substrate attraction strength.

  11. Modeling and Optimization for Interpenetrating polymer

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    Modeling and Optimization for Interpenetrating polymer network process 1 Weijie Lin, Lorenz T #12;Project Overview · IPN Interpenetrating polymer network ­ A combination of two polymers in a network form Fig. 2 An IPN process example · Typical Sequential Type of Process Fig. 1 IPN network

  12. Novel polyoxazolines polymer drug delivery platform

    E-Print Network [OSTI]

    performed with 4 different polymers in multi- drug resistant (MCF7/ADR) human adenocarcinoma cells, non-resistant (MCF7) human adenocarcinoma cells and Madin-Darby canine kidney (MDCK) cells. All polymers were found lines. 2. To investigate the effect of the addition of drugs to the polymers on cell toxicity, micelles

  13. Organosiloxane-grafted natural polymer coatings

    DOE Patents [OSTI]

    Sugama, Toshifumi (Wading River, NY)

    1998-01-01T23:59:59.000Z

    A new family of polysaccharide graft polymers are provided as corrosion resistant coatings having antimicrobial properties which are useful on light metals such as aluminum, magnesium, zinc, steel and their alloys. Methods of making the polysaccharide graft polymers are also included. The methods of making the polysaccharide graft polymers involve reacting a polysaccharide source with an antimicrobial agent under conditions of hydrolysis-condensation.

  14. Polymer microcantilevers fabricated via multiphoton absorption polymerization

    E-Print Network [OSTI]

    Teich, Malvin C.

    Polymer microcantilevers fabricated via multiphoton absorption polymerization Z. Bayindir, Y. Sun polymer cantilevers. Atomic force microscopy has been used to characterize the mechanical properties orders of magnitude smaller than would be predicted from the properties of the bulk polymer.6 If correct

  15. Nordic Polymer Days 2006 Copenhagen, Denmark

    E-Print Network [OSTI]

    Abstract Nordic Polymer Days 2006 Copenhagen, Denmark Polyacrylamide nanosensor embedded Scharff-Poulsen, c Hong Gu, d Wolf B. Fromme, b Iver Jakobsen, a Kristoffer Almdal a The Danish Polymer-linked polymer in nanometer scale, have several advantages over direct loading of cells with fluorescent probes

  16. Polymers in a Vacuum J. M. Deutsch

    E-Print Network [OSTI]

    Deutsch, Josh

    Polymers in a Vacuum J. M. Deutsch Department of Physics, University of California, Santa Cruz polymer molecules are found in a vacuum, and here we examine their properties. Angular momentum The properties of polymer chains have been investigated extensively over the past 50 years [1], but the vast

  17. North Dakota State University Postoc Biobased Polymers

    E-Print Network [OSTI]

    Alpay, S. Pamir

    North Dakota State University Postoc ­ Biobased Polymers A postdoctoral position is available in the area of synthesis and characterization of novel biobased thermosetting polymer systems for coatings will include the synthesis of monomers and polymers, preparation of coatings, thermosets, etc., preparation

  18. Selfattractive random polymers Remco van der Hofstad

    E-Print Network [OSTI]

    Klenke, Achim

    Self­attractive random polymers Remco van der Hofstad Stieltjes Institute of Mathematics Delft polymer of finite length in Zd . Its law is that of a finite simple random walk path in Zd receiving that for > the attraction dominates the repulsion, i.e., with high probability the polymer is contained in a finite box

  19. Anion exchange polymer electrolytes

    DOE Patents [OSTI]

    Kim, Yu Seung; Kim, Dae Sik; Lee, Kwan-Soo

    2013-07-23T23:59:59.000Z

    Solid anion exchange polymer electrolytes and compositions comprising chemical compounds comprising a polymeric core, a spacer A, and a guanidine base, wherein said chemical compound is uniformly dispersed in a suitable solvent and has the structure: ##STR00001## wherein: i) A is a spacer having the structure O, S, SO.sub.2, --NH--, --N(CH.sub.2).sub.n, wherein n=1-10, --(CH.sub.2).sub.n--CH.sub.3--, wherein n=1-10, SO.sub.2-Ph, CO-Ph, ##STR00002## wherein R.sub.5, R.sub.6, R.sub.7 and R.sub.8 each are independently --H, --NH.sub.2, F, Cl, Br, CN, or a C.sub.1-C.sub.6 alkyl group, or any combination of thereof; ii) R.sub.9, R.sub.10, R.sub.11, R.sub.12, or R.sub.13 each independently are --H, --CH.sub.3, --NH.sub.2, --NO, --CH.sub.nCH.sub.3 where n=1-6, HC.dbd.O--, NH.sub.2C.dbd.O--, --CH.sub.nCOOH where n=1-6, --(CH.sub.2).sub.n--C(NH.sub.2)--COOH where n=1-6, --CH--(COOH)--CH.sub.2--COOH, --CH.sub.2--CH(O--CH.sub.2CH.sub.3).sub.2, --(C.dbd.S)--NH.sub.2, --(C.dbd.NH)--N--(CH.sub.2).sub.nCH.sub.3, where n=0-6, --NH--(C.dbd.S)--SH, --CH.sub.2--(C.dbd.O)--O--C(CH.sub.3).sub.3, --O--(CH.sub.2).sub.n--CH--(NH.sub.2)--COOH, where n=1-6, --(CH.sub.2).sub.n--CH.dbd.CH wherein n=1-6, --(CH.sub.2).sub.n--CH--CN wherein n=1-6, an aromatic group such as a phenyl, benzyl, phenoxy, methylbenzyl, nitrogen-substituted benzyl or phenyl groups, a halide, or halide-substituted methyl groups; and iii) wherein the composition is suitable for use in a membrane electrode assembly.

  20. Evaluation of bitumen by realization of bitumen/polymer blends

    SciTech Connect (OSTI)

    Cogneau, P.; Goosse, S. [Parc Industriel, Perwez (Belgium)

    1995-12-31T23:59:59.000Z

    Today, if we want to guarantee the durability of bitumen/polymer blends and membranes, characterization of bitumen by penetration hardness and softening point is not enough. Bitumen which is a {open_quotes}residue{close_quotes} of distillation is a poor relation of the petrochemistry. It will tend to become more so in view of the more sophisticated treatment units of the heavy components coming from refining. This paper will present the correlation existing between generic composition of bitumen and the characteristics of the bitumen/polymers (atatic polypropylene) blends. The generic composition of the bitumen is determined by thin layer chromatography associated with a detection flame ionization (Iatroscan method). More than 20 bitumens of different origins have been studied. The quality of the blends done with an EPP batch for each of these bitumens is acquired by using determination trials of viscosity, cold bending (new state and after aging), segregation, and morphological analyses.

  1. Determining the Preston constants of low-dielectric-constant polymers

    E-Print Network [OSTI]

    Eusner, Thor

    2006-01-01T23:59:59.000Z

    An important step in the manufacture of integrated circuits (ICs) is the Chemical Mechanical Polishing (CMP) process. In order to effectively use CMP, the removal rates of the materials used in ICs must be known. The removal ...

  2. Association of length-slow silica with evaporites

    SciTech Connect (OSTI)

    Heaney, P.J. (Princeton Univ., Princeton, NJ (United States). Dept. of Geology); Sheppard, R.A. (Geological Survey, Denver, CO (United States). Denver Federal Center); Post, J.E. (Smithsonian Inst., Washington, DC (United States). Dept. of Mineral Sciences)

    1992-01-01T23:59:59.000Z

    In 1971, Folk and Pittman described the common occurrence of length-slow quartz (or lutecite) with evaporitic minerals, and they suggested that lutecite might be a useful indicator for vanished evaporites. However, the subsequent discoveries of length-slow silica in carbonate turbidites and in abyssal Pacific cherts revealed that lutecite is not restricted to near-surface deposits. Moreover, Kastner found that length-slow quartz could be crystallized in slightly alkaline solutions enriched in Mg[sup 2+], Na[sup +], and SO[sub 4][sup [minus]2]. Following these studies, researchers have cited the presence of lutecite in rock samples as suggestive but not compelling evidence for an evaporitic origin, and the precise nature of this form of silica has remained somewhat enigmatic. Investigations of chert nodules from evaporitic and non-evaporitic regimes support an identification of length-slow quartz'' with the mineral moganite, a polymorph of silica that is fibrous and optically length slow. Results are based upon X-ray powder diffraction of the chert, followed by Rietveld refinement of the X-ray patterns to quantify the weight fraction of quartz and moganite in each specimen. Most non-evaporitic chert appears to contain between 5 and 15 wt. % moganite, but evaporitic cherts often contain more than 20 wt. %. Cherts that have transformed from precursor magadiite can be particularly rich in moganite; samples from Lake Magadi, Kenya and from Harney Lake, Oregon revealed about equal parts moganite and quartz. However, the observation of decreasing abundances of moganite in rocks of increasing age indicates that moganite is metastable relative to quartz.

  3. Thermal annealing of laser damage precursors on fused silica surfaces

    SciTech Connect (OSTI)

    Shen, N; Miller, P E; Bude, J D; Laurence, T A; Suratwala, T I; Steele, W A; Feit, M D; Wang, L L

    2012-03-19T23:59:59.000Z

    Previous studies have identified two significant precursors of laser damage on fused silica surfaces at fluenes below {approx} 35 J/cm{sup 2}, photoactive impurities in the polishing layer and surface fractures. In the present work, isothermal heating is studied as a means of remediating the highly absorptive, defect structure associated with surface fractures. A series of Vickers indentations were applied to silica surfaces at loads between 0.5N and 10N creating fracture networks between {approx} 10{micro}m and {approx} 50{micro}m in diameter. The indentations were characterized prior to and following thermal annealing under various times and temperature conditions using confocal time-resolved photo-luminescence (CTP) imaging, and R/1 optical damage testing with 3ns, 355nm laser pulses. Significant improvements in the damage thresholds, together with corresponding reductions in CTP intensity, were observed at temperatures well below the glass transition temperature (T{sub g}). For example, the damage threshold on 05.N indentations which typically initiates at fluences <8 J/cm{sup 2} could be improved >35 J/cm{sup 2} through the use of a {approx} 750 C thermal treatment. Larger fracture networks required longer or higher temperature treatment to achieve similar results. At an annealing temperature > 1100 C, optical microscopy indicates morphological changes in some of the fracture structure of indentations, although remnants of the original fracture and significant deformation was still observed after thermal annealing. This study demonstrates the potential of using isothermal annealing as a means of improving the laser damage resistance of fused silica optical components. Similarly, it provides a means of further understanding the physics associated with optical damage and related mitigation processes.

  4. The production of activated silica with carbon dioxide gas

    E-Print Network [OSTI]

    Hayes, William Bell

    1956-01-01T23:59:59.000Z

    Ional to the per cent of carbon dioxi. de 1n the flue gas for a constant total gas flow rate. REFE REN CES l. Andrews, R. V, , Hanford Works Eocument (1952), 2. Andrews, R. V. & J. A. W. W. A, , ~46 82 (1954). 3. Andrews, R. V, , Personal Communication 4... of the reciuire . ents for the dedree of iliASTER OF SCIENCE Janus', 1956 Major Subject: Chemi. cal Engineering TH PRODUCTION OP ACTIVATED SILICA 7iIITH CARBON DIOXIDE GAS A Thesis William Bell Hayes III Approved as to style and content by: Chairmen...

  5. Chemical treatment for silica-containing glass surfaces

    DOE Patents [OSTI]

    Grabbe, A.; Michalske, T.A.; Smith, W.L.

    1998-04-07T23:59:59.000Z

    Dehydroxylated, silica-containing, glass surfaces are known to be at least partially terminated by strained siloxane rings. According to the invention, a surface of this kind is exposed to a selected silane compound or mixture of silane compounds under reaction-promoting conditions. The ensuing reaction results in opening of the strained siloxane rings, and termination of surface atoms by chemical species, such as organic or organosilicon species, having desirable properties. These species can be chosen to provide qualities such as hydrophobicity, or improved coupling to a polymeric coating. 11 figs.

  6. Chemical treatment for silica-containing glass surfaces

    DOE Patents [OSTI]

    Grabbe, Alexis (Albuquerque, NM); Michalske, Terry Arthur (Cedar Crest, NM); Smith, William Larry (Albuquerque, NM)

    1998-01-01T23:59:59.000Z

    Dehydroxylated, silica-containing, glass surfaces are known to be at least partially terminated by strained siloxane rings. According to the invention, a surface of this kind is exposed to a selected silane compound or mixture of silane compounds under reaction-promoting conditions. The ensuing reaction results in opening of the strained siloxane rings, and termination of surface atoms by chemical species, such as organic or organosilicon species, having desirable properties. These species can be chosen to provide qualities such as hydrophobicity, or improved coupling to a polymeric coating.

  7. Method for chemical surface modification of fumed silica particles

    DOE Patents [OSTI]

    Grabbe, Alexis (Albuquerque, NM); Michalske, Terry Arthur (Cedar Crest, NM); Smith, William Larry (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    Dehydroxylated, silica-containing, glass surfaces are known to be at least partially terminated by strained siloxane rings. According to the invention, a surface of this kind is exposed to a selected silane compound or mixture of silane compounds under reaction-promoting conditions. The ensuing reaction results in opening of the strained siloxane rings, and termination of surface atoms by chemical species, such as organic or organosilicon species, having desirable properties. These species can be chosen to provide qualities such as hydrophobicity, or improved coupling to a polymeric coating.

  8. Chemical treatment for silica-containing glass surfaces

    DOE Patents [OSTI]

    Grabbe, Alexis (Albuquerque, NM); Michalske, Terry Arthur (Cedar Crest, NM); Smith, William Larry (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    Dehydroxylated, silica-containing, glass surfaces are known to be at least partially terminated by strained siloxane rings. According to the invention, a surface of this kind is exposed to a selected silane compound or mixture of silane compounds under reaction-promoting conditons. The ensuing reaction results in opening of the strained siloxane rings, and termination of surface atoms by chemical species, such as organic or organosilicon species, having desirable properties. These species can be chosen to provide qualities such as hydrophobicity, or improved coupling to a polymeric coating.

  9. Method for chemical surface modification of fumed silica particles

    DOE Patents [OSTI]

    Grabbe, A.; Michalske, T.A.; Smith, W.L.

    1999-05-11T23:59:59.000Z

    Dehydroxylated, silica-containing, glass surfaces are known to be at least partially terminated by strained siloxane rings. According to the invention, a surface of this kind is exposed to a selected silane compound or mixture of silane compounds under reaction-promoting conditions. The ensuing reaction results in opening of the strained siloxane rings, and termination of surface atoms by chemical species, such as organic or organosilicon species, having desirable properties. These species can be chosen to provide qualities such as hydrophobicity, or improved coupling to a polymeric coating. 11 figs.

  10. Chemical treatment for silica-containing glass surfaces

    DOE Patents [OSTI]

    Grabbe, Alexis (Albuquerque, NM); Michalske, Terry Arthur (Bernalillo, NM); Smith, William Larry (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    Dehydroxylated, silica-containing, glass surfaces are known to be at least partially terminated by strained siloxane rings. According to the invention, a surface of this kind is exposed to a selected silane compound or mixture of silane compounds under reaction-promoting conditions. The ensuing reaction results in opening of the strained siloxane rings, and termination of surface atoms by chemical species, such as organic or organosilicon species, having desirable properties. These species can be chosen to provide qualities such as hydrophobicity, or improved coupling to a polymeric coating.

  11. Controlled release of ibuprofen by meso–macroporous silica

    SciTech Connect (OSTI)

    Santamaría, E., E-mail: esthersantamaria@ub.edu; Maestro, A.; Porras, M.; Gutiérrez, J.M.; González, C.

    2014-02-15T23:59:59.000Z

    Structured meso–macroporous silica was successfully synthesized from an O/W emulsion using decane as a dispersed phase. Sodium silicate solution, which acts as a silica source and a poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (EO{sub 19}PO{sub 39}EO{sub 19}) denoted as P84 was used in order to stabilize the emulsion and as a mesopore template. The materials obtained were characterized through transmission electron microscopy (TEM), scanning electron microscopy (SEM), small-angle X-ray diffraction scattering (SAXS) and nitrogen adsorption–desorption isotherms. Ibuprofen (IBU) was selected as the model drug and loaded into ordered meso–macroporous materials. The effect of the materials’ properties on IBU drug loading and release was studied. The results showed that the loading of IBU increases as the macropore presence in the material is increased. The IBU adsorption process followed the Langmuir adsorption isotherm. A two-step release process, consisting of an initial fast release and then a slower release was observed. Macropores enhanced the adsorption capacity of the material; this was probably due to the fact that they allowed the drug to access internal pores. When only mesopores were present, ibuprofen was probably adsorbed on the mesopores close to the surface. Moreover, the more macropore present in the material, the slower the release behaviour observed, as the ibuprofen adsorbed in the internal pores had to diffuse along the macropore channels up to the surface of the material. The material obtained from a highly concentrated emulsion was functionalized with amino groups using two methods, the post-grafting mechanism and the co-condensation mechanism. Both routes improve IBU adsorption in the material and show good behaviour as a controlled drug delivery system. - Graphical abstract: Ibuprofen release profiles for the materials obtained from samples P84{sub m}eso (black diamonds), P84{sub 2}0% (white squares), P84{sub 5}0% (black triangles), P84{sub 7}5% (white diamonds), P84{sub 7}5% functionalized by grafting (black squares) and P84{sub 7}5% functionalized by co-condensation method (white triangles). Display Omitted - Highlights: • Ordered meso–macroporous material is used as a controlled delivery system for ibuprofen. • Incorporation of macropores in mesoporous silica improves ibuprofen adsorption. • Meso–macroporous structures provide a lower delivery than mesoporous silica. • APTES functionalization in meso–macroporous materials improves ibuprofen adsorption and delivery behaviour.

  12. Optical and radiographical characterization of silica aerogel for Cherenkov radiator

    E-Print Network [OSTI]

    Tabata, Makoto; Hatakeyama, Yoshikiyo; Kawai, Hideyuki; Morita, Takeshi; Nishikawa, Keiko

    2012-01-01T23:59:59.000Z

    We present optical and X-ray radiographical characterization of silica aerogels with refractive index from 1.05 to 1.07 for a Cherenkov radiator. A novel pin-drying method enables us to produce highly transparent hydrophobic aerogels with high refractive index by shrinking wet-gels. In order to investigate the uniformity in the density (i.e., refractive index) of an individual aerogel monolith, we use the laser Fraunhofer method, an X-ray absorption technique, and Cherenkov imaging by a ring imaging Cherenkov detector in a beam test. We observed an increase in density at the edge of the aerogel tiles, produced by pin-drying.

  13. Optical and radiographical characterization of silica aerogel for Cherenkov radiator

    E-Print Network [OSTI]

    Makoto Tabata; Ichiro Adachi; Yoshikiyo Hatakeyama; Hideyuki Kawai; Takeshi Morita; Keiko Nishikawa

    2012-07-17T23:59:59.000Z

    We present optical and X-ray radiographical characterization of silica aerogels with refractive index from 1.05 to 1.07 for a Cherenkov radiator. A novel pin-drying method enables us to produce highly transparent hydrophobic aerogels with high refractive index by shrinking wet-gels. In order to investigate the uniformity in the density (i.e., refractive index) of an individual aerogel monolith, we use the laser Fraunhofer method, an X-ray absorption technique, and Cherenkov imaging by a ring imaging Cherenkov detector in a beam test. We observed an increase in density at the edge of the aerogel tiles, produced by pin-drying.

  14. Preparation of silica aerogels with improved mechanical properties and extremely low thermal conductivities through modified sol-gel process

    E-Print Network [OSTI]

    Zuo, Yanjia

    2010-01-01T23:59:59.000Z

    Reported silica aerogels have a thermal conductivity as low as 15 mW/mK. The fragility of silica aerogels, however, makes them impractical for structural applications. The purpose of the study is to improve the ductility ...

  15. Release mechanism utilizing shape memory polymer material

    DOE Patents [OSTI]

    Lee, Abraham P. (Walnut Creek, CA); Northrup, M. Allen (Berkeley, CA); Ciarlo, Dino R. (Livermore, CA); Krulevitch, Peter A. (Pleasanton, CA); Benett, William J. (Livermore, CA)

    2000-01-01T23:59:59.000Z

    Microfabricated therapeutic actuators are fabricated using a shape memory polymer (SMP), a polyurethane-based material that undergoes a phase transformation at a specified temperature (Tg). At a temperature above temperature Tg material is soft and can be easily reshaped into another configuration. As the temperature is lowered below temperature Tg the new shape is fixed and locked in as long as the material stays below temperature Tg. Upon reheating the material to a temperature above Tg, the material will return to its original shape. By the use of such SMP material, SMP microtubing can be used as a release actuator for the delivery of embolic coils through catheters into aneurysms, for example. The microtubing can be manufactured in various sizes and the phase change temperature Tg is determinate for an intended temperature target and intended use.

  16. Electronically conductive polymer composites and microstructures

    SciTech Connect (OSTI)

    Van Dyke, L.S.

    1993-01-01T23:59:59.000Z

    Composites of electronically conductive polymers with insulating host materials are investigated. A template synthesis method was developed for the production of electronically conductive polymer microstructures. In template synthesis the pores of a porous host membrane act as templates for the polymerization of a conductive polymer. The template synthetic method can be used to form either solid microfibrils or hollow microtubules. The electrochemical properties of conductive polymers produced via the template synthesis method are superior to those of conventionally synthesized conductive polymers. Electronically conductive polymers are used to impart conductivity to non-conductive materials. Two different approaches are used. First, thin film composites of conductive polymers with fluoropolymers are made by the polymerization of conductive polymers onto fluoropolymer films. Modification of the fluoropolymer surface prior to conductive polymer polymerization is necessary to obtain good adhesion between the two materials. The difference in adhesion of the conductive polymer to the modified and unmodified fluoropolymer surfaces can be used to pattern the conductive polymer coating. Patterning of the conductive polymer coating can alternatively be done via UV laser ablation of the conductive polymer. The second method by which conductive polymers were used to impart conductivity to an insulating polymer was via the formation of a graft copolymer. In this approach, heterocyclic monomers grafted to an insulating polyphosphazene backbone were polymerized to yield semiconductive materials. Finally the measurement of electrolyte concentration in polypyrrole and the effects of hydroxide anion on the electrochemical and electrical properties of polypyrrole are described. It is shown that treatment of polypyrrole with hydroxide anion increases the potential window over which polypyrrole is a good electronic conductor.

  17. Pulsed infrared laser annealing of gold nanoparticles embedded in a silica A. Halabica,1,a

    E-Print Network [OSTI]

    Pennycook, Steve

    Pulsed infrared laser annealing of gold nanoparticles embedded in a silica matrix A. Halabica,1,a J; published online 28 April 2008 Pulsed infrared laser irradiation was used to modify the optical and physical in a fused-silica matrix. The experiments demonstrate the unique effects of fast thermal heating

  18. DENSIFICATION AS THE ONLY MECHANISM AT STAKE DURING INDENTATION OF SILICA GLASS?

    E-Print Network [OSTI]

    Brest, Université de

    DENSIFICATION AS THE ONLY MECHANISM AT STAKE DURING INDENTATION OF SILICA GLASS? Vincent Keryvin1 mariette.nivard@univ-rennes1.fr, f jean-christophe.sangleboeuf@univ-rennes1.fr Keywords: Indentation; Glass; Densification; Plasticity; Imprint; Modeling; Finite-Element Analysis; Fused quartz Abstract. Silica glass

  19. The effect of silica nanoparticle-modified surfaces on cell morphology, cytoskeletal organization and function

    E-Print Network [OSTI]

    substrates were coated with monodispersed silica nanoparticles of 50, 100 and 300 nm in diameter. The impactThe effect of silica nanoparticle-modified surfaces on cell morphology, cytoskeletal organization investigate the effect of nanoparticle (NP) assemblies arranged on a flat substrate on cytoskeletal

  20. The influence of void space on antireflection coatings of silica nanoparticle self-assembled films

    E-Print Network [OSTI]

    Heflin, Randy

    The influence of void space on antireflection coatings of silica nanoparticle self-assembled films This study investigates the deposition by ionic self-assembly of alternating silica nanoparticle and poly allyamine hydrochloride layers with the goal to create a single-material antireflection coating

  1. Ionic effects on silica optical fiber strength and models for fatigue V. V. Rondinella

    E-Print Network [OSTI]

    Matthewson, M. John

    Ionic effects on silica optical fiber strength and models for fatigue V. V. Rondinella M. J. Matthewson Rutgers University, Fiber Optic Materials Research Program P. 0. Box 909, Piscataway, NJ 08855, flaw free silica optical fiber shows significant differences from the bulk material for poorly

  2. Effects of silica nanoparticle addition to the secondary coating of dual-coated optical fibers

    E-Print Network [OSTI]

    Matthewson, M. John

    Effects of silica nanoparticle addition to the secondary coating of dual-coated optical fibers J Available online 30 March 2006 Abstract The mechanical and optical properties of dual-coated optical fibers of silica nanoparticles in the secondary coating is shown to enhance the resistance of optical fibers

  3. Effect of chemical stripping on the strength and surface morphology of fused silica optical fiber

    E-Print Network [OSTI]

    Matthewson, M. John

    Effect of chemical stripping on the strength and surface morphology of fused silica optical fiber V. V. Rondinella M. J. Matthewson Fiber Optic Materials Research Program Department of Ceramics Rutgers University, Piscataway, NJ 08855-0909 ABSTRACT Examination of the surface profile of silica optical fiber

  4. Developing a process for commercial silica production from Salton Sea brines

    SciTech Connect (OSTI)

    Bourcier, W; McCutcheon, M; Leif, R; Bruton, C

    2000-09-25T23:59:59.000Z

    The goal of this joint LLNL-CalEnergy project is to develop a method for precipitating marketable silica from spent Salton Sea Geothermal Field (SSGF) brines. Many markets for silica exist. We have initially targeted production of silica as a rubber additive. Silica reinforced rubber gives tires less rolling resistance, greater tear strength, and better adhesion to steel belts. Previous silica precipitates produced by CalEnergy from Salton Sea brines were not suitable as rubber additives. They did not to disperse well in the rubber precursors and produced inferior rubber. CalEnergy currently minimizes silica scaling in some of their production facilities by acidifying the brine pH. The rate of silica precipitation slows down as the pH is lowered, so that energy extraction and brine reinfection are possible without unacceptable amounts of scaling even with more than 700 ppm SiO{sub 2} in solution. We are adding a step in which a small amount of base is added to the acidified brine to precipitate silica before reinfection. By carefully controlling the type, rate, and amount of base addition, we can optimize the properties of the precipitate to approach those of an ideal rubber additive.

  5. DOI: 10.1002/adma.200701303 Nanolayered Carbon/Silica Superstructures via Organosilane

    E-Print Network [OSTI]

    Zhu, Yuntian T.

    . A main advantage using mesoporous silica is to synthesize carbon/silica composite materials with tunable of amorphous carbon materials after carbonization, and uncontrolled morphologies of composite materials is typically high. However, the composites are not uniform; car- bonization mainly produces amorphous carbon

  6. Titanium-assisted growth of silica nanowires: from surface-matched to free-standing morphologies

    E-Print Network [OSTI]

    Nabben, Reinhard

    Titanium-assisted growth of silica nanowires: from surface-matched to free-standing morphologies.1088/0957-4484/22/40/405604 Titanium-assisted growth of silica nanowires: from surface-matched to free-standing morphologies G Callsen1

  7. Integrated Optical Orbital Angular Momentum Multiplexing Device using 3-D Waveguides and a Silica PLC

    E-Print Network [OSTI]

    Yoo, S. J. Ben

    PLC Binbin Guan,1 Ryan P. Scott,1 Nicolas K. Fontaine,2 Tiehui Su,1 Carlo Ferrari,3 Mark Cappuzzo,3 on a silica planar lightwave circuit (PLC) coupled to a 3-D photonic circuit that efficiently generates planar lightwave circuit (PLC) with a silica 3-D PIC that supports up to 15 OAM modes, both TE and TM

  8. ORIGINAL PAPER Algal-silica cycling and pigment diagenesis in recent alpine

    E-Print Network [OSTI]

    Konhauser, Kurt

    dis- solved within 50 years of deposition. Diatom dissolu- tion, silica recycling, and diageneticO2, hereafter BSi) in lake sediments that has led to their common use in freshwater paleoecology have the lowest preservation potential for diatom frustules. However, the recycling of diatom silica

  9. Method of forming a foamed thermoplastic polymer

    DOE Patents [OSTI]

    Duchane, D.V.; Cash, D.L.

    1984-11-21T23:59:59.000Z

    A solid thermoplastic polymer is immersed in an immersant solution comprising a compatible carrier solvent and an infusant solution containing an incompatible liquid blowing agent for a time sufficient for the immersant solution to infuse into the polymer. The carrier solvent is then selectively extracted, preferably by a solvent exchange process in which the immersant solution is gradually diluted with and replaced by the infusant solution, so as to selectively leave behind the infustant solution permanently entrapped in the polymer. The polymer is then heated to volatilize the blowing agent and expand the polymer into a foamed state.

  10. Stretching of polymers in a turbulent environment

    E-Print Network [OSTI]

    Bruno Eckhardt; Jochen Kronjaeger; Joerg Schumacher

    2002-01-20T23:59:59.000Z

    The interaction of polymers with small-scale velocity gradients can trigger a coil-stretch transition in the polymers. We analyze this transition within a direct numerical simulation of shear turbulence with an Oldroyd-B model for the polymer. In the coiled state the lengths of polymers are distributed algebraically with an exponent alpha=2 gamma-1/De, where gamma is a characteristic stretching rate of the flow and De the Deborah number. In the stretched state we demonstrate that the length distribution of the polymers is limited by the feedback to the flow.

  11. Friction between Ring Polymer Brushes

    E-Print Network [OSTI]

    A. Erbas; J. Paturej

    2015-01-07T23:59:59.000Z

    Friction between ring-polymer brushes at melt densities sliding past each other are studied using extensive course-grained molecular dynamics simulations and scaling arguments, and the results are compared to the friction between linear-polymer brushes. We show that for a velocity range spanning over three decades, the frictional forces measured for ring-polymer brushes are half the corresponding friction in case of linear brushes. In the linear-force regime, the weak inter-digitation of two ring brushes compared to linear brushes also leads to a lower number of binary collisions between the monomers of opposing brushes. At high velocities, where the thickness of the inter-digitation layer between two opposing brushes is on the order monomer size regardless of brush topology, stretched segments of ring polymers take a double-stranded conformation. As a result, monomers of the double-stranded segments collide less with the monomers of the opposing ring brush even though a similar number of monomers occupies the inter-digitation layer for ring and linear-brush bilayers. The numerical data obtained from our simulations is consistent with the proposed scaling analysis. Conformation-dependent frictional reduction observed in ring brushes can have important consequences in non-equilibrium bulk systems.

  12. Enhanced photophysics of conjugated polymers

    DOE Patents [OSTI]

    Chen, Liaohai (Darien, IL)

    2007-06-12T23:59:59.000Z

    A particulate fluorescent conjugated polymer surfactant complex and method of making and using same. The particles are between about 15 and about 50 nm and when formed from a lipsome surfactant have a charge density similar to DNA and are strongly absorbed by cancer cells.

  13. Polymer representations and geometric quantization

    E-Print Network [OSTI]

    Miguel Campiglia

    2011-11-02T23:59:59.000Z

    Polymer representations of the Weyl algebra of linear systems provide the simplest analogues of the representation used in loop quantum gravity. The construction of these representations is algebraic, based on the Gelfand-Naimark-Segal construction. Is it possible to understand these representations from a Geometric Quantization point of view? We address this question for the case of a two dimensional phase space.

  14. Water-soluble conductive polymers

    DOE Patents [OSTI]

    Aldissi, M.

    1988-02-12T23:59:59.000Z

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  15. Water-soluble conductive polymers

    DOE Patents [OSTI]

    Aldissi, Mahmoud (Sante Fe, NM)

    1989-01-01T23:59:59.000Z

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  16. Water-soluble conductive polymers

    DOE Patents [OSTI]

    Aldissi, Mahmoud (Sante Fe, NM)

    1990-01-01T23:59:59.000Z

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  17. Characterization of zirconia- and niobia-silica mixture coatings produced by ion-beam sputtering

    SciTech Connect (OSTI)

    Melninkaitis, Andrius; Tolenis, Tomas; Mazule, Lina; Mirauskas, Julius; Sirutkaitis, Valdas; Mangote, Benoit; Fu Xinghai; Zerrad, Myriam; Gallais, Laurent; Commandre, Mireille; Kicas, Simonas; Drazdys, Ramutis

    2011-03-20T23:59:59.000Z

    ZrO{sub 2}-SiO{sub 2} and Nb{sub 2}O{sub 5}-SiO{sub 2} mixture coatings as well as those of pure zirconia (ZrO{sub 2}), niobia (Nb{sub 2}O{sub 5}), and silica (SiO{sub 2}) deposited by ion-beam sputtering were investigated. Refractive-index dispersions, bandgaps, and volumetric fractions of materials in mixed coatings were analyzed from spectrophotometric data. Optical scattering, surface roughness, nanostructure, and optical resistance were also studied. Zirconia-silica mixtures experience the transition from crystalline to amorphous phase by increasing the content of SiO{sub 2}. This also results in reduced surface roughness. All niobia and silica coatings and their mixtures were amorphous. The obtained laser-induced damage thresholds in the subpicosecond range also correlates with respect to the silica content in both zirconia- and niobia-silica mixtures.

  18. Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Jiangquan Zhang and D. Grischkowsky*

    E-Print Network [OSTI]

    Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Vapors Jiangquan time-domain spectroscopy (THz-TDS) study of hydrophobic and hydrophilic silica aerogels, and the adsorption of several molecular vapors in the hydrophilic silica aerogel. The hydrophobic and hydrophilic

  19. Aluminum and silica intake in drinking water and the risk of Alzheimer's disease or cognitive decline: findings of the

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Aluminum and silica intake in drinking water and the risk of Alzheimer's disease or cognitive,2 , Commenges Daniel1,2 , Helmer Catherine2,3 , Jean-François Dartigues2,3 . Abbreviations: Al, Aluminum; AD, Alzheimer's Disease; MMSE, Mini Mental State Examination; Si, Silica Running head: Aluminum, silica in water

  20. Active Polymers Confer Fast Reorganization Kinetics

    E-Print Network [OSTI]

    Douglas Swanson; Ned S. Wingreen

    2011-10-02T23:59:59.000Z

    Many cytoskeletal biopolymers are "active," consuming energy in large quantities. In this Letter, we identify a fundamental difference between active polymers and passive, equilibrium polymers: for equal mean lengths, active polymers can reorganize faster than equilibrium polymers. We show that equilibrium polymers are intrinsically limited to linear scaling between mean lifetime and mean length, MFPT ~ , by analogy to 1-d Potts models. By contrast, we present a simple active-polymer model that improves upon this scaling, such that MFPT ~ ^{1/2}. Since to be biologically useful, structural biopolymers must typically be many monomers long, yet respond dynamically to the needs of the cell, the difference in reorganization kinetics may help to justify active polymers' greater energy cost. PACS numbers: 87.10.Ed, 87.16.ad, 87.16.Ln

  1. The LHCb RICH silica aerogel performance with LHC data

    E-Print Network [OSTI]

    Perego, D L

    2010-01-01T23:59:59.000Z

    In the LHCb detector at the Large Hadron Collider, powerful charged particle identification is performed by Ring Imaging Cherenkov (RICH) technology. In order to cover the full geometric acceptance and the wide momentum range (1-100 GeV/c), two detectors with three Cherenkov radiators have been designed and installed. In the medium (10-40 GeV/c) and high (30-100 GeV/c) momentum range, gas radiators are used (C4F10 and CF4 respectively). In the low momentum range (1 to a few GeV/c) pion/kaon/proton separation will be done with photons produced in solid silica aerogel. A set of 16 tiles, with the large transverse dimensions ever (20x20 cm$^2$) and nominal refractive index 1.03 have been produced. The tiles have excellent optical properties and homogeneity of refractive index within the tile of ~1%. The first data collected at LHC are used to understand the behaviour of the RICH: preliminary results will be presented and discussed on the performance of silica aerogel and of the gas radiators C4F10 and CF4.

  2. Crowding of Polymer Coils and Demixing in Nanoparticle-Polymer Mixtures

    E-Print Network [OSTI]

    Ben Lu; Alan R. Denton

    2011-06-24T23:59:59.000Z

    The Asakura-Oosawa-Vrij (AOV) model of colloid-polymer mixtures idealizes nonadsorbing polymers as effective spheres that are fixed in size and impenetrable to hard particles. Real polymer coils, however, are intrinsically polydisperse in size (radius of gyration) and may be penetrated by smaller particles. Crowding by nanoparticles can affect the size distribution of polymer coils, thereby modifying effective depletion interactions and thermodynamic stability. To analyse the influence of crowding on polymer conformations and demixing phase behaviour, we adapt the AOV model to mixtures of nanoparticles and ideal, penetrable polymer coils that can vary in size. We perform Gibbs ensemble Monte Carlo simulations, including trial nanoparticle-polymer overlaps and variations in radius of gyration. Results are compared with predictions of free-volume theory. Simulation and theory consistently predict that ideal polymers are compressed by nanoparticles and that compressibility and penetrability stabilise nanoparticle-polymer mixtures.

  3. Polymer compositions, polymer films and methods and precursors for forming same

    DOE Patents [OSTI]

    Klaehn, John R; Peterson, Eric S; Orme, Christopher J

    2013-09-24T23:59:59.000Z

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  4. Optical Properties and London Dispersion Forces of Amorphous Silica Determined by Vacuum Ultraviolet Spectroscopy and

    E-Print Network [OSTI]

    Rollins, Andrew M.

    for semiconductor fabrication, re- cently as a potential 157 nm mask substrate. The optical properties in the vacuum, optical fibers, and microelectronics such as metal oxide semiconductor transistors, etc.1 It also forms is tetrahedrally coordinated with four oxygen atoms and each oxygen atom serves as a bridge connecting two

  5. Improved Mobility Control for Carbon Dioxide (CO{sub 2}) Enhanced Oil Recovery Using Silica-Polymer-Initiator (SPI) Gels

    SciTech Connect (OSTI)

    Oglesby, Kenneth

    2014-01-31T23:59:59.000Z

    SPI gels are multi-component silicate based gels for improving (areal and vertical) conformance in oilfield enhanced recovery operations, including water-floods and carbon dioxide (CO{sub 2}) floods, as well as other applications. SPI mixtures are like-water when pumped, but form light up to very thick, paste-like gels in contact with CO{sub 2}. When formed they are 3 to 10 times stronger than any gelled polyacrylamide gel now available, however, they are not as strong as cement or epoxy, allowing them to be washed / jetted out of the wellbore without drilling. This DOE funded project allowed 8 SPI field treatments to be performed in 6 wells (5 injection wells and 1 production well) in 2 different fields with different operators, in 2 different basins (Gulf Coast and Permian) and in 2 different rock types (sandstone and dolomite). Field A was in a central Mississippi sandstone that injected CO{sub 2} as an immiscible process. Field B was in the west Texas San Andres dolomite formation with a mature water-alternating-gas miscible CO{sub 2} flood. Field A treatments are now over 1 year old while Field B treatments have only 4 months data available under variable WAG conditions. Both fields had other operational events and well work occurring before/ during / after the treatments making definitive evaluation difficult. Laboratory static beaker and dynamic sand pack tests were performed with Ottawa sand and both fields’ core material, brines and crude oils to improve SPI chemistry, optimize SPI formulations, ensure SPI mix compatibility with field rocks and fluids, optimize SPI treatment field treatment volumes and methods, and ensure that strong gels set in the reservoir. Field quality control procedures were designed and utilized. Pre-treatment well (surface) injectivities ranged from 0.39 to 7.9 MMCF/psi. The SPI treatment volumes ranged from 20.7 cubic meters (m{sup 3}, 5460 gallons/ 130 bbls) to 691 m{sup 3} (182,658 gallons/ 4349 bbls). Various size and types of chemical/ water buffers before and after the SPI mix ensured that pre-gelled SPI mix got out into the formation before setting into a gel. SPI gels were found to be 3 to 10 times stronger than any commercially available cross-linked polyacrylamide gels based on Penetrometer and Bulk Gel Shear Testing. Because of SPI’s unique chemistry with CO{sub 2}, both laboratory and later field tests demonstrated that multiple, smaller volume SPI treatments maybe more effective than one single large SPI treatment. CO{sub 2} injectivities in injection well in both fields were reduced by 33 to 70% indicating that injected CO{sub 2} is now going into new zones. This reduction has lasted 1+ year in Field A. Oil production increased and CO{sub 2} production decreased in 5 Field A production wells, offsets to Well #1 injector, for a total of about 2,250 m{sup 3} (600,000 gallons/ 14,250 bbls) of incremental oil production- a $140 / SPI bbl return. Treated marginal production well, Field A Well #2, immediately began showing increased oil production totaling 238 m{sup 3} (63,000 gallons/ 1500 BBLs) over 1 year and an immediate 81% reduced gas-oil ratio.

  6. Preconcentration of uranium in seawater with heterocyclic azo dyes supported on silica gel

    SciTech Connect (OSTI)

    Ueda, K.; Koshino, Y.; Yamamoto, Y.

    1985-11-01T23:59:59.000Z

    The chelating adsorbents, heterocyclic azo dyes supported on silica gel, were prepared and their adsorption behaviors of metal ions were investigated. The 1-(2-pyridylazo)-2-naphthol(PAN)-SG and 2-(2-thiazolylazo)-p-cresol(TAC)-SG show greater affinity for UO/sub 2/(II) and ZrO(II), compared with the other metal ions like Cu, Cd, Fe and alkaline earths. Trace uranyl can be quantitatively retained on the column of the gels at neutral pH region and flowrate 3-4 ml/min. The uranyl retained is easily eluted from the column bed with a mixture of acetone and nitric acid (9:1 v/v) and determined by spectrophotometry using Arsenazo-III. Matrix components in seawater do not interfere and the spiked recovery of uranyl in artificial seawater was found to be average 98.6%, with the relative standard deviation of 1.08%. Both gels were applied to the determination of uranium in seawater with satisfactory results. 16 references, 3 figures, 3 tables.

  7. The role of polymer formation during vapor phase lubrication of silicon.

    SciTech Connect (OSTI)

    Dugger, Michael Thomas; Dirk, Shawn M.; Ohlhausen, James Anthony

    2010-10-01T23:59:59.000Z

    The lubrication of silicon surfaces with alcohol vapors has recently been demonstrated. With a sufficient concentration of pentanol vapor present, sliding of a silica ball on an oxidized silicon wafer can proceed with no measurable wear. The initial results of time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis of wear surfaces revealed a reaction product having thickness on the order of a monolayer, and with an ion spectrum that included fragments having molecular weights of 200 or more that occurred only inside the wear tracks. The parent alcohol molecule pentanol, has molecular weight of 88amu, suggesting that reactions of adsorbed alcohols on the wearing surfaces allowed polymerization of the alcohols to form higher molecular weight species. In addition to pin-on-disk studies, lubrication of silicon surfaces with pentanol vapors has also been demonstrated using MicroElectroMechanical Systems (MEMS) devices. Recent investigations of the reaction mechanisms of the alcohol molecules with the oxidized silicon surfaces have shown that wearless sliding requires a concentration of the alcohol vapor that is dependent upon the contact stress during sliding, with higher stress requiring a greater concentration of alcohol. Different vapor precursors including those with acid functionality, olefins, and methyl termination also produce polymeric reaction products, and can lubricate the silica surfaces. Doping the operating environment with oxygen was found to quench the formation of the polymeric reaction product, and demonstrates that polymer formation is not necessary for wearless sliding.

  8. Silica–silica Polyimide Buffered Optical Fibre Irradiation and Strength Experiment at Cryogenic Temperatures for 355 nm Pulsed Lasers

    E-Print Network [OSTI]

    Takala, E; Bordini, B; Bottura, L; Bremer, J; Rossi, L

    2012-01-01T23:59:59.000Z

    A controlled UV-light delivery system is envisioned to be built in order to study the stability properties of superconducting strands. The application requires a wave guide from room temperature to cryogenic temperatures. Hydrogen loaded and unloaded polyimide buffered silica–silica 100 microm core fibres were tested at cryogenic temperatures. A thermal stress test was done at 1.9 K and at 4.2 K which shows that the minimal mechanical bending radius for the fibre can be 10 mm for testing (transmission was not measured). The cryogenic transmission loss was measured for one fibre to assess the magnitude of the transmission decrease due to microbending that takes place during cooldown. UV-irradiation degradation measurements were done for bent fibres at 4.2 K with a deuterium lamp and 355 nm pulsed lasers. The irradiation tests show that the fibres have transmission degradation only for wavelengths smaller than 330 nm due to the two photon absorption. The test demonstrates that the fibres are suitable for the ...

  9. Apoptosis induction by silica nanoparticles mediated through reactive oxygen species in human liver cell line HepG2

    SciTech Connect (OSTI)

    Ahmad, Javed [Department of Zoology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia)] [Department of Zoology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Ahamed, Maqusood, E-mail: maqusood@gmail.com [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia)] [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Akhtar, Mohd Javed [Fibre Toxicology, CSIR-Indian Institute of Toxicology Research, Lucknow-226001 (India)] [Fibre Toxicology, CSIR-Indian Institute of Toxicology Research, Lucknow-226001 (India); Alrokayan, Salman A. [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia)] [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Siddiqui, Maqsood A.; Musarrat, Javed; Al-Khedhairy, Abdulaziz A. [Department of Zoology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia)] [Department of Zoology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia)

    2012-03-01T23:59:59.000Z

    Silica nanoparticles are increasingly utilized in various applications including agriculture and medicine. In vivo studies have shown that liver is one of the primary target organ of silica nanoparticles. However, possible mechanisms of hepatotoxicity caused by silica nanoparticles still remain unclear. In this study, we explored the reactive oxygen species (ROS) mediated apoptosis induced by well-characterized 14 nm silica nanoparticles in human liver cell line HepG2. Silica nanoparticles (25–200 ?g/ml) induced a dose-dependent cytotoxicity in HepG2 cells. Silica nanoparticles were also found to induce oxidative stress in dose-dependent manner indicated by induction of ROS and lipid peroxidation and depletion of glutathione (GSH). Quantitative real-time PCR and immunoblotting results showed that both the mRNA and protein expressions of cell cycle checkpoint gene p53 and apoptotic genes (bax and caspase-3) were up-regulated while the anti-apoptotic gene bcl-2 was down-regulated in silica nanoparticles treated cells. Moreover, co-treatment of ROS scavenger vitamin C significantly attenuated the modulation of apoptotic markers along with the preservation of cell viability caused by silica nanoparticles. Our data demonstrated that silica nanoparticles induced apoptosis in human liver cells, which is ROS mediated and regulated through p53, bax/bcl-2 and caspase pathways. This study suggests that toxicity mechanisms of silica nanoparticles should be further investigated at in vivo level. -- Highlights: ? We explored the mechanisms of toxicity caused by silica NPs in human liver HepG2 cells. ? Silica NPs induced a dose-dependent cytotoxicity in HepG2 cells. ? Silica NPs induced ROS generation and oxidative stress in a dose-dependent manner. ? Silica NPs were also modulated apoptosis markers both at mRNA and protein levels. ? ROS mediated apoptosis induced by silica NPs was preserved by vitamin C.

  10. Rapid switching in electrochromic devices based on complementary conducting polymer films

    SciTech Connect (OSTI)

    Sapp, S.A.; Sotzing, G.A.; Reddinger, J.L.; Reynolds, J.R. [Univ. of Florida, Gainesville, FL (United States)

    1996-10-01T23:59:59.000Z

    The search for stable, rapid switching electrochromic materials that are easy and inexpensive to process has become the focus of a great deal of research in the past few years. Conducting and electroactive polymers are one class of electrochromic materials which may offer a low cost alternative to the traditional metal oxide materials that have been studied in depth. These materials also offer the advantages of having rapid switching rates and a well defined chemical structure. Recently, there have been many new conducting polymer systems developed which exhibit complementary electrochromic behavior and undergo reversible redox chemistry. This presentation will focus on the design, fabrication, and characterization of electrochromic devices based on complementary conducting polymers as cathodic and anodic electrochromic materials. Spectroelectrochemistry results and switching rate determinations will be discussed for two of these polymer based electrochromic devices.

  11. Generalized Entropy Theory of Glass Formation in Polymer Melts with Specific Interactions

    E-Print Network [OSTI]

    Wen-Sheng Xu; Karl F. Freed

    2015-03-21T23:59:59.000Z

    Chemical structure has been long recognized to greatly influence polymer glass formation, but a general molecular theory that predicts how chemical structure determines the properties of glass-forming polymers has been slow to develop. While the generalized entropy theory (GET) explains the influence of various molecular details on polymer glass formation, the application of the GET has heretofore been limited to the use of the simplest polymer model in which all united atom groups within the monomers of a species interact with a common monomer averaged van der Waals energy. However, energetic heterogeneities are ubiquitous within the monomers of real polymers, and their implications for polymer glass formation remain to be investigated theoretically. This paper uses an extension of the GET to explore the influence of energetic heterogeneities within monomers upon the nature of polymer glass formation. The present paper focuses on establishing general trends for the variation of characteristic properties of glass formation, such as the isobaric fragility parameter $m_P$ and the glass transition temperature $T_g$, with molecular details, such as the specific interactions and chain stiffness. Our computations confirm that the previously used model with monomer averaged interactions correctly captures general trends in the variation of $m_P$ and $T_g$ with various molecular parameters. More importantly, adjustment of the energetic heterogeneities within monomers alone are shown to provide an efficient mechanism for tailoring the properties of glass-forming polymers. The variations of polymer properties along iso-fragility and iso-$T_g$ lines are illustrated as important design tools for exhibiting the combined influence of specific interactions and chain stiffness.

  12. Unzipping an adsorbed polymer in a dirty or random environment

    E-Print Network [OSTI]

    Rajeev Kapri; Somendra M. Bhattacharjee

    2005-11-16T23:59:59.000Z

    The phase diagram of unzipping of an adsorbed directed polymer in two dimensions in a random medium has been determined. Both the hard-wall and the soft-wall cases are considered. Exact solutions for the pure problem with different affinities on the two sides are given. The results obtained by the numerical procedure adopted here are shown to agree with the exact results for the pure case. The characteristic exponents for unzipping for the random problem are different from the pure case. The distribution functions for the unzipped length, first bubble, and the spacer are determined.

  13. INFLUENCE OF PHENYLTRIMETHOXYSILANE ON PHYSICOCHEMICAL PROPERTIES OF TEOS BASED MONOLITHIC SILICA AEROGELS PREPARED BY SUPERCRITICAL DRYING PROCESS

    E-Print Network [OSTI]

    Kavale Mahendra S; Mahadik D. B; Parale V. G; Mane P. B; Vhatkar R. S; A. Venkateswara Rao; Wagh P. B; Satish C. Gupta

    The objective of the present research work is to synthesize transparent, hydrophobic, monolithic silica aerogels with ultralow density by using supercritical drying process. The effect of phenyltrimethoxysilane as a hydrophobic reagent on the physicochemical properties of the silica aerogels has been studied. The total processing time for the synthesis of monolithic silica aerogels minimized to 29 h which was ~2 days. We have succeeded to get ultralow density of the silica aerogels as low as 24 Kgm-3 with 165 ° water droplet contact angle. The ultralow density affects the thermal conductivity of the silica aerogels.

  14. Cathodoluminescence microscopy and petrographic image analysis of aggregates in concrete pavements affected by alkali-silica reaction

    SciTech Connect (OSTI)

    Stastna, A., E-mail: astastna@gmail.com [Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Praha 2 (Czech Republic); Sachlova, S.; Pertold, Z.; Prikryl, R. [Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Praha 2 (Czech Republic); Leichmann, J. [Department of Geological Sciences, Faculty of Science, Masaryk University in Brno, Kotlarska 267/2, 611 37 Brno (Czech Republic)

    2012-03-15T23:59:59.000Z

    Various microscopic techniques (cathodoluminescence, polarizing and electron microscopy) were combined with image analysis with the aim to determine a) the modal composition and degradation features within concrete, and b) the petrographic characteristics and the geological types (rocks, and their provenance) of the aggregates. Concrete samples were taken from five different portions of Highway Nos. D1, D11, and D5 (the Czech Republic). Coarse and fine aggregates were found to be primarily composed of volcanic, plutonic, metamorphic and sedimentary rocks, as well as of quartz and feldspar aggregates of variable origins. The alkali-silica reaction was observed to be the main degradation mechanism, based upon the presence of microcracks and alkali-silica gels in the concrete. Use of cathodoluminescence enabled the identification of the source materials of the quartz aggregates, based upon their CL characteristics (i.e., color, intensity, microfractures, deformation, and zoning), which is difficult to distinguish only employing polarizing and electron microscopy. - Highlights: Black-Right-Pointing-Pointer ASR in concrete pavements on the Highways Nos. D1, D5 and D11 (Czech Republic). Black-Right-Pointing-Pointer Cathodoluminescence was combined with various microscopic techniques and image analysis. Black-Right-Pointing-Pointer ASR was attributed to aggregates. Black-Right-Pointing-Pointer Source materials of aggregates were identified based on cathodoluminescence characteristics. Black-Right-Pointing-Pointer Quartz comes from different volcanic, plutonic and metamorphic parent rocks.

  15. Mesoporous silica nanoparticles for biomedical and catalytical applications

    SciTech Connect (OSTI)

    Sun, Xiaoxing

    2011-05-15T23:59:59.000Z

    Mesoporous silica materials, discovered in 1992 by the Mobile Oil Corporation, have received considerable attention in the chemical industry due to their superior textual properties such as high surface area, large pore volume, tunable pore diameter, and narrow pore size distribution. Among those materials, MCM-41, referred to Mobile Composition of Matter NO. 41, contains honeycomb liked porous structure that is the most common mesoporous molecular sieve studied. Applications of MCM-41 type mesoporous silica material in biomedical field as well as catalytical field have been developed and discussed in this thesis. The unique features of mesoporous silica nanoparticles were utilized for the design of delivery system for multiple biomolecules as described in chapter 2. We loaded luciferin into the hexagonal channels of MSN and capped the pore ends with gold nanoparticles to prevent premature release. Luciferase was adsorbed onto the outer surface of the MSN. Both the MSN and the gold nanoparticles were protected by poly-ethylene glycol to minimize nonspecific interaction of luciferase and keep it from denaturating. Controlled release of luciferin was triggered within the cells and the enzymatic reaction was detected by a luminometer. Further developments by varying enzyme/substrate pairs may provide opportunities to control cell behavior and manipulate intracellular reactions. MSN was also served as a noble metal catalyst support due to its large surface area and its stability with active metals. We prepared MSN with pore diameter of 10 nm (LP10-MSN) which can facilitate mass transfer. And we successfully synthesized an organo silane, 2,2'-Bipyridine-amide-triethoxylsilane (Bpy-amide-TES). Then we were able to functionalize LP10-MSN with bipyridinyl group by both post-grafting method and co-condensation method. Future research of this material would be platinum complexation. This Pt (II) complex catalyst has been reported for a C-H bond activation reaction as an alternative of the traditional Friedel-Crafts reaction. And we will compare the turnover numbers of MSN supported material with homogenous catalyst to evaluate the catalytical efficiency of our material.

  16. Polymer system for gettering hydrogen

    DOE Patents [OSTI]

    Shepodd, Timothy Jon (330 Thrasher Ave., Livermore, Alameda County, CA 94550); Whinnery, LeRoy L. (4929 Julie St., Livermore, Alameda County, CA 94550)

    2000-01-01T23:59:59.000Z

    A novel composition comprising organic polymer molecules having carbon-carbon double bonds, for removing hydrogen from the atmosphere within enclosed spaces. Organic polymers molecules containing carbon-carbon double bonds throughout their structures, preferably polybutadiene, polyisoprene and derivatives thereof, intimately mixed with an insoluble catalyst composition, comprising a hydrogenation catalyst and a catalyst support, preferably Pd supported on carbon, provide a hydrogen getter composition useful for removing hydrogen from enclosed spaces even in the presence of contaminants such as common atmospheric gases, water vapor, carbon dioxide, ammonia, oil mists, and water. The hydrogen getter composition disclosed herein is particularly useful for removing hydrogen from enclosed spaces containing potentially explosive mixtures of hydrogen and oxygen.

  17. Model-based experimental analysis for inter-polymer process

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    ) + Polyethylene (PE) ARCEL TOUGH FLEXIBLE Advanced packaging material Interpenetrating polymer network productModel-based experimental analysis for inter-polymer process CMU: Weijie Lin, Lorenz T. Biegler processed in a sequential way Polymer A Polymer B Project overview Inter-polymer process #12;Project

  18. Ris-PhD-18(EN) Patterning Biomolecules on Polymer

    E-Print Network [OSTI]

    Risø-PhD-18(EN) Patterning Biomolecules on Polymer Surfaces for Applications in Life Sciences Susan on Polymer Surfaces for Applications in Life Sciences. Department: Danish Polymer Centre, Risø National: Danish Polymer Centre, Risø National Laboratory. Centre for Nanostructured polymer surfaces for medical

  19. Amorphous silica in ultra-high performance concrete: First hour of hydration

    SciTech Connect (OSTI)

    Oertel, Tina, E-mail: tina.oertel@isc.fraunhofer.de [Fraunhofer-Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Chair for Inorganic Chemistry I, Universität Bayreuth, Universitätsstr. 30, 95440 Bayreuth (Germany); Hutter, Frank [Fraunhofer-Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Helbig, Uta, E-mail: uta.helbig@th-nuernberg.de [Chair for Crystallography and X-ray Methods, Technische Hochschule Nürnberg Georg Simon Ohm, Wassertorstraße 10, 90489 Nürnberg (Germany); Sextl, Gerhard [Fraunhofer-Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Chair for Chemical Technology of Advanced Materials, Julius Maximilian Universität, Röntgenring 11, 97070 Würzburg (Germany)

    2014-04-01T23:59:59.000Z

    Amorphous silica in the sub-micrometer size range is widely used to accelerate cement hydration. Investigations including properties of silica which differ from the specific surface area are rare. In this study, the reactivity of varying types of silica was evaluated based on their specific surface area, surface silanol group density, content of silanol groups and solubility in an alkaline suspension. Pyrogenic silica, silica fume and silica synthesized by hydrolysis and condensation of alkoxy silanes, so-called Stoeber particles, were employed. Influences of the silica within the first hour were further examined in pastes with water/cement ratios of 0.23 using in-situ X-ray diffraction, cryo scanning electron microscopy and pore solution analysis. It was shown that Stoeber particles change the composition of the pore solution. Na{sup +}, K{sup +}, Ca{sup 2+} and silicate ions seem to react to oligomers. The extent of this reaction might be highest for Stoeber particles due to their high reactivity.

  20. Encapsulated in silica: genome, proteome and physiology of the thermophilic bacterium Anoxybacillus flavithermus

    SciTech Connect (OSTI)

    Saw, Jimmy H [Los Alamos National Laboratory; Mountain, Bruce W [NEW ZEALAND; Feng, Lu [NANKAI UNIV; Omelchenko, Marina V [NCBI/NLM/NIH; Hou, Shaobin [UNIV OF HAWAII; Saito, Jennifer A [UNIV OF HAWAII; Stott, Matthew B [NEW ZEALAND; Li, Dan [NANKAI UNIV; Zhao, Guang [NANKAI UNIV; Wu, Junli [NANKAI UNIV; Galperin, Michael Y [NCBI/NLM/NIH; Koonin, Eugene V [NCBI/NLM/NIH; Makarova, Kira S [NCBI/NLM/NIH; Wolf, Yuri I [NCBI/NLM/NIH; Rigden, Daniel J [UNIV OF LIVERPOOL; Dunfield, Peter F [UNIV OF CALGARY; Wang, Lei [NANKAI UNIV; Alam, Maqsudul [UNIV OF HAWAII

    2008-01-01T23:59:59.000Z

    Gram-positive bacteria of the genus Anoxybacillus have been found in diverse thermophilic habitats, such as geothermal hot springs and manure, and in processed foods such as gelatin and milk powder. Anoxybacillus flavithermus is a facultatively anaerobic bacterium found in super-saturated silica solutions and in opaline silica sinter. The ability of A. flavithermus to grow in super-saturated silica solutions makes it an ideal subject to study the processes of sinter formation, which might be similar to the biomineralization processes that occurred at the dawn of life. We report here the complete genome sequence of A. flavithermus strain WK1, isolated from the waste water drain at the Wairakei geothermal power station in New Zealand. It consists of a single chromosome of 2,846,746 base pairs and is predicted to encode 2,863 proteins. In silico genome analysis identified several enzymes that could be involved in silica adaptation and biofilm formation, and their predicted functions were experimentally validated in vitro. Proteomic analysis confirmed the regulation of biofilm-related proteins and crucial enzymes for the synthesis of long-chain polyamines as constituents of silica nanospheres. Microbial fossils preserved in silica and silica sinters are excellent objects for studying ancient life, a new paleobiological frontier. An integrated analysis of the A. flavithermus genome and proteome provides the first glimpse of metabolic adaptation during silicification and sinter formation. Comparative genome analysis suggests an extensive gene loss in the Anoxybacillus/Geobacillus branch after its divergence from other bacilli.

  1. Electrically conductive polymer concrete coatings

    DOE Patents [OSTI]

    Fontana, J.J.; Elling, D.; Reams, W.

    1990-03-13T23:59:59.000Z

    A sprayable electrically conductive polymer concrete coating for vertical d overhead applications is described. The coating is permeable yet has low electrical resistivity (<10 ohm-cm), good bond strength to concrete substrates, and good weatherability. A preferred formulation contains about 60 wt % calcined coke breeze, 40 wt % vinyl ester with 3.5 wt % modified bentonite clay. Such formulations apply evenly and provide enough rigidity for vertical or overhead structures so there is no drip or sag.

  2. Diamond turning of thermoplastic polymers

    SciTech Connect (OSTI)

    Smith, E.; Scattergood, R.O.

    1988-12-01T23:59:59.000Z

    Single point diamond turning studies were made using a series of thermoplastic polymers with different glass transition temperatures. Variations in surface morphology and surface roughness were observed as a function of cutting speed. Lower glass transition temperatures facilitate smoother surface cuts and better surface finish. This can be attributed to the frictional heating that occurs during machining. Because of the very low glass transition temperatures in polymeric compared to inorganic glasses, the precision machining response can be very speed sensitive.

  3. Electrically conductive polymer concrete coatings

    DOE Patents [OSTI]

    Fontana, Jack J. (Shirley, NY); Elling, David (Centereach, NY); Reams, Walter (Shirley, NY)

    1990-01-01T23:59:59.000Z

    A sprayable electrically conductive polymer concrete coating for vertical d overhead applications is described. The coating is permeable yet has low electrical resistivity (<10 ohm-cm), good bond strength to concrete substrates, and good weatherability. A preferred formulation contains about 60 wt % calcined coke breeze, 40 wt % vinyl ester with 3.5 wt % modified bentonite clay. Such formulations apply evenly and provide enough rigidity for vertical or overhead structures so there is no drip or sag.

  4. Electrically conductive polymer concrete coatings

    DOE Patents [OSTI]

    Fontana, J.J.; Elling, D.; Reams, W.

    1988-05-26T23:59:59.000Z

    A sprayable electrically conductive polymer concrete coating for vertical and overhead applications is described. The coating is permeable yet has low electrical resistivity (<10 ohm-cm), good bond strength to concrete substrates, and good weatherability. A preferred formulation contains about 60 wt% calcined coke breeze, 40 wt% vinyl ester resin with 3.5 wt% modified bentonite clay. Such formulations apply evenly and provide enough rigidity for vertical or overhead structures so there is no drip or sag. 4 tabs.

  5. Solid-polymer-electrolyte fuel cells

    SciTech Connect (OSTI)

    Fuller, T.F.

    1992-07-01T23:59:59.000Z

    A transport model for polymer electrolytes is presented, based on concentrated solution theory and irreversible thermodynamics. Thermodynamic driving forces are developed, transport properties are identified and experiments devised. Transport number of water in Nafion 117 membrane is determined using a concentration cell. It is 1.4 for a membrane equilibrated with saturated water vapor at 25{degrees}C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the water content approaches zero. The relation between transference number, transport number, and electroosmotic drag coefficient is presented, and their relevance to water-management is discussed. A mathematical model of transport in a solid-polymer-electrolyte fuel cell is presented. A two-dimensional membrane-electrode assembly is considered. Water management, thermal management, and utilization of fuel are examined in detail. The membrane separators of these fuel cells require sorbed water to maintain conductivity; therefore it is necessary to manage the water content in membranes to ensure efficient operation. Water and thermal management are interrelated. Rate of heat removal is shown to be a critical parameter in the operation of these fuel cells. Current-voltage curves are presented for operation on air and reformed methanol. Equations for convective diffusion to a rotating disk are solved numerically for a consolute point between the bulk concentration and the surface. A singular-perturbation expansion is presented for the condition where the bulk concentration is nearly equal to the consolute-point composition. Results are compared to Levich`s solution and analysis.

  6. Unbiased charge oscillations in DNA monomer-polymers and dimer-polymers

    E-Print Network [OSTI]

    Lambropoulos, Konstantinos; Morphis, Andreas; Kaklamanis, Konstantinos; Theodorakou, Marina; Simserides, Constantinos

    2015-01-01T23:59:59.000Z

    We call {\\it monomer} a B-DNA base-pair and examine, analytically and numerically, electron or hole oscillations in monomer- and dimer-polymers, i.e., periodic sequences with repetition unit made of one or two monomers. We employ a tight-binding (TB) approach at the base-pair level to readily determine the spatiotemporal evolution of a single extra carrier along a $N$ base-pair polymer. We study HOMO and LUMO eigenspectra as well as the mean over time probabilities to find the carrier at a particular monomer. We use the pure mean transfer rate $k$ to evaluate the easiness of charge transfer. The inverse decay length $\\beta$ for exponential fits $k(d)$, where $d$ is the charge transfer distance, and the exponent $\\eta$ for power law fits $k(N)$ are computed; generally power law fits are better. We illustrate that increasing the number of different parameters involved in the TB description, the fall of $k(d)$ or $k(N)$ becomes steeper and show the range covered by $\\beta$ and $\\eta$. Finally, both for the time-...

  7. Characterization of ?-carrageenan and its derivative based green polymer electrolytes

    SciTech Connect (OSTI)

    Jumaah, Fatihah Najirah; Mobaraka, Nadhratun Naiim; Ahmad, Azizan; Ramli, Nazaruddin [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor Darul Ehsan (Malaysia)

    2013-11-27T23:59:59.000Z

    The new types of green polymer electrolytes based on ?-carrageenan derivative have been prepared. ?-carrageenan act as precursor was reacted with monochloroacetic acid to produce carboxymethyl ?-carrageenan. The powders were characterized by Attenuated Total Reflection Fourier Transform infrared (ATR-FTIR) spectroscopy and {sup 1}H nuclear magnetic resonance (NMR) to confirm the substitution of targeted functional group in ?-carrageenan. The green polymer electrolyte based on ?-carrageenan and carboxymethyl ?-carrageenan was prepared by solution-casting technique. The films were characterized by electrochemical impedance spectroscopy to determine the ionic conductivity. The ionic conductivity ?-carrageenan film were higher than carboxymethyl ?-carrageenan which 4.87 ×10{sup ?6} S cm{sup ?1} and 2.19 ×10{sup ?8} S cm{sup ?1}, respectively.

  8. Polymer Field-Theory Simulations on Graphics Processing Units

    E-Print Network [OSTI]

    Kris T. Delaney; Glenn H. Fredrickson

    2012-04-24T23:59:59.000Z

    We report the first CUDA graphics-processing-unit (GPU) implementation of the polymer field-theoretic simulation framework for determining fully fluctuating expectation values of equilibrium properties for periodic and select aperiodic polymer systems. Our implementation is suitable both for self-consistent field theory (mean-field) solutions of the field equations, and for fully fluctuating simulations using the complex Langevin approach. Running on NVIDIA Tesla T20 series GPUs, we find double-precision speedups of up to 30x compared to single-core serial calculations on a recent reference CPU, while single-precision calculations proceed up to 60x faster than those on the single CPU core. Due to intensive communications overhead, an MPI implementation running on 64 CPU cores remains two times slower than a single GPU.

  9. Worm-like Polymer Loops and Fourier Knots

    E-Print Network [OSTI]

    S. Rappaport; Y. Rabin; A. Yu. Grosberg

    2006-03-02T23:59:59.000Z

    Every smooth closed curve can be represented by a suitable Fourier sum. We show that the ensemble of curves generated by randomly chosen Fourier coefficients with amplitudes inversely proportional to spatial frequency (with a smooth exponential cutoff), can be accurately mapped on the physical ensemble of worm-like polymer loops. We find that measures of correlation on the scale of the entire loop yield a larger persistence length than that calculated from the tangent-tangent correlation function at small length scales. The conjecture that physical loops exhibit additional rigidity on scales comparable to the entire loop due to the contribution of twist rigidity, can be tested experimentally by determining the persistence length from the local curvature and comparing it with that obtained by measuring the radius of gyration of dsDNA plasmids. The topological properties of the ensemble randomly generated worm-like loops are shown to be similar to that of other polymer models.

  10. Mechanical Loss in Tantala/Silica Dielectric Mirror Coatings

    E-Print Network [OSTI]

    Steven D. Penn; Peter H. Sneddon; Helena Armandula; Joseph C. Betzwieser; Gianpietro Cagnoli; Jordan Camp; D. R. M. Crooks; Martin M. Fejer; Andri M. Gretarsson; Gregory M. Harry; Jim Hough; Scott E. Kittelberger; Michael J. Mortonson; Roger Route; Sheila Rowan; Christophoros C. Vassiliou

    2003-02-24T23:59:59.000Z

    Current interferometric gravitational wave detectors use test masses with mirror coatings formed from multiple layers of dielectric materials, most commonly alternating layers of SiO2 (silica) and Ta2O5 (tantala). However, mechanical loss in the Ta2O5/SiO2 coatings may limit the design sensitivity for advanced detectors. We have investigated sources of mechanical loss in the Ta2O5/SiO2 coatings, including loss associated with the coating-substrate interface, with the coating-layer interfaces, and with the bulk material. Our results indicate that the loss is associated with the bulk coating materials and that the loss of Ta2O5 is substantially larger than that of SiO2.

  11. Effect of polymer chemistry on globular protein–polymer block copolymer self-assembly

    E-Print Network [OSTI]

    Chang, Dongsook

    Bioconjugates of the model red fluorescent protein mCherry and synthetic polymer blocks with different hydrogen bonding functionalities show that the chemistry of the polymer block has a large effect on both ordering ...

  12. Solid polymer electrolytes for rechargeable batteries

    SciTech Connect (OSTI)

    Narang, S.C.; Macdonald, D.D.

    1990-11-01T23:59:59.000Z

    SRI International has synthesized novel solid polymer electrolytes for high energy density, rechargeable lithium batteries. We have systematically replaced the oxygens in PEO with sulfur to reduce the strong hard-acid hard-base interaction, while retaining the favorable helical conformation of the polymer backbone. The best polymer electrolyte produced so far is suitable for a medium power battery. In another effort, we have synthesized single ion conducting polymer electrolytes based on polyethyleneimine, polyphosphazene, and polysiloxane backbones. The single ion conducting polymer electrolytes will allow greater depth of charge and discharge by preventing dc polarization. The best conductivity so far with single ion conductors is 1.0 {times} 10{sup {minus}3} Scm{sup {minus}1} at room temperature. Further optimization of electrical and mechanical properties will allow the use of these polymer electrolytes in the fabrication of rechargeable lithium batteries. 8 tabs.

  13. Synthesis and characterization of barium ferrite–silica nanocomposites

    SciTech Connect (OSTI)

    Aguilar-González, M.A.; Mendoza-Suárez, G.; Padmasree, K.P., E-mail: padma512@yahoo.com

    2013-10-15T23:59:59.000Z

    In this work, we prepared barium ferrite-silica (BaM-SiO{sub 2}) nanocomposites of different molar ratios by high-energy ball milling, followed by heat-treatment at different temperatures. The microstructure, morphology and magnetic properties were characterized for different synthesis conditions by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The results indicate that 15 h of milling was enough to avoid the generation of hematite phase and to get a good dispersion of barium ferrite particles in the ceramic matrix. For milling periods beyond 15 h and heat treatment above 900 °C, the XRD patterns showed the presence of hematite phase caused by the decomposition of BaM. The agglomerate size observed through SEM analysis was around 150 nm with a good BaM dispersion into the SiO{sub 2} matrix. The highest saturation magnetization (Ms) value obtained was 43 emu/g and the corresponding coercivity (Hc) value of 3.4 kOe for the composition 60BaM-40SiO{sub 2} milled for 15 h and heat treated at 900 °C. This coercivity value is acceptable for the application in magnetic recording media. Highlights: • Barium ferrite–silica nanocomposites were prepared by high energy ball milling. • Optimal processing time is 15 h milling and heat treatment at 900 °C. • This is enough to avoid the generation of hematite phase. • Obtain good dispersion of barium ferrite particles in the ceramic matrix • Above this processing time shows the presence of increased amount of hematite.

  14. Studies of Immobilized Homogeneous Metal Catalysts on Silica Supports

    SciTech Connect (OSTI)

    Keith James Stanger

    2003-05-31T23:59:59.000Z

    The tethered, chiral, chelating diphosphine rhodium complex, which catalyzes the enantioselective hydrogenation of methyl-{alpha}-acetamidocinnamate (MAC), has the illustrated structure as established by {sup 31}P NMR and IR studies. Spectral and catalytic investigations also suggest that the mechanism of action of the tethered complex is the same as that of the untethered complex in solution. The rhodium complexes, [Rh(COD)H]{sub 4}, [Rh(COD){sub 2}]{sup +}BF{sub 4}{sup -}, [Rh(COD)Cl]{sub 2}, and RhCl{sub 3} {center_dot} 3H{sub 2}O, adsorbed on SiO{sub 2} are optimally activated for toluene hydrogenation by pretreatment with H{sub 2} at 200 C. The same complexes on Pd-SiO{sub 2} are equally active without pretreatments. The active species in all cases is rhodium metal. The catalysts were characterized by XPS, TEM, DRIFTS, and mercury poisoning experiments. Rhodium on silica catalyzes the hydrogenation of fluorobenzene to produce predominantly fluorocyclohexane in heptane and 1,2-dichloroethane solvents. In heptane/methanol and heptane/water solvents, hydrodefluorination to benzene and subsequent hydrogenation to cyclohexane occurs exclusively. Benzene inhibits the hydrodefluorination of fluorobenzene. In DCE or heptane solvents, fluorocyclohexane reacts with hydrogen fluoride to form cyclohexene. Reaction conditions can be chosen to selectively yield fluorocyclohexane, cyclohexene, benzene, or cyclohexane. The oxorhenium(V) dithiolate catalyst [-S(CH{sub 2}){sub 3}s-]Re(O)(Me)(PPh{sub 3}) was modified by linking it to a tether that could be attached to a silica support. Spectroscopic investigation and catalytic oxidation reactivity showed the heterogenized catalyst's structure and reactivity to be similar to its homogeneous analog. However, the immobilized catalyst offered additional advantages of recyclability, extended stability, and increased resistance to deactivation.

  15. Outline Directed polymers Log-gamma polymer KPZ equation Fluctuation exponents for certain 1+1 dimensional

    E-Print Network [OSTI]

    Seppäläinen, Timo

    Outline Directed polymers Log-gamma polymer KPZ equation Fluctuation exponents for certain 1+1 dimensional directed polymers Timo Sepp¨al¨ainen Department of Mathematics University of Wisconsin-Madison MSRI December 2010 Fluctuation exponents for polymers 1/36 #12;Outline Directed polymers Log

  16. Photoinitiated grafting of porous polymer monoliths and thermoplastic polymers for microfluidic devices

    DOE Patents [OSTI]

    Frechet, Jean M. J. (Oakland, CA); Svec, Frantisek (Alameda, CA); Rohr, Thomas (Leiden, NL)

    2008-10-07T23:59:59.000Z

    A microfluidic device preferably made of a thermoplastic polymer that includes a channel or a multiplicity of channels whose surfaces are modified by photografting. The device further includes a porous polymer monolith prepared via UV initiated polymerization within the channel, and functionalization of the pore surface of the monolith using photografting. Processes for making such surface modifications of thermoplastic polymers and porous polymer monoliths are set forth.

  17. Tritium containing polymers having a polymer backbone substantially void of tritium

    DOE Patents [OSTI]

    Jensen, G.A.; Nelson, D.A.; Molton, P.M.

    1992-03-31T23:59:59.000Z

    A radioluminescent light source comprises a solid mixture of a phosphorescent substance and a tritiated polymer. The solid mixture forms a solid mass having length, width, and thickness dimensions, and is capable of self-support. In one aspect of the invention, the phosphorescent substance comprises solid phosphor particles supported or surrounded within a solid matrix by a tritium containing polymer. The tritium containing polymer comprises a polymer backbone which is essentially void of tritium. 2 figs.

  18. Tritium containing polymers having a polymer backbone substantially void of tritium

    DOE Patents [OSTI]

    Jensen, George A. (Richland, WA); Nelson, David A. (Richland, WA); Molton, Peter M. (Richland, WA)

    1992-01-01T23:59:59.000Z

    A radioluminescent light source comprises a solid mixture of a phosphorescent substance and a tritiated polymer. The solid mixture forms a solid mass having length, width, and thickness dimensions, and is capable of self-support. In one aspect of the invention, the phosphorescent substance comprises solid phosphor particles supported or surrounded within a solid matrix by a tritium containing polymer. The tritium containing polymer comprises a polymer backbone which is essentially void of tritium.

  19. Organosiloxane-grafted natural polymer coatings

    DOE Patents [OSTI]

    Sugama, Toshifumi

    1998-12-01T23:59:59.000Z

    A new family of polysaccharide graft polymers are provided as corrosion resistant coatings having antimicrobial properties which are useful on light metals such as aluminum, magnesium, zinc, steel and their alloys. Methods of making the polysaccharide graft polymers are also included. The methods of making the polysaccharide graft polymers involve reacting a polysaccharide source with an antimicrobial agent under conditions of hydrolysis-condensation. 17 figs.

  20. Asphaltenes-based polymer nano-composites

    DOE Patents [OSTI]

    Bowen, III, Daniel E

    2013-12-17T23:59:59.000Z

    Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

  1. Nanoscale molecularly imprinted polymers and method thereof

    DOE Patents [OSTI]

    Hart, Bradley R. (Brentwood, CA); Talley, Chad E. (Brentwood, CA)

    2008-06-10T23:59:59.000Z

    Nanoscale molecularly imprinted polymers (MIP) having polymer features wherein the size, shape and position are predetermined can be fabricated using an xy piezo stage mounted on an inverted microscope and a laser. Using an AMF controller, a solution containing polymer precursors and a photo initiator are positioned on the xy piezo and hit with a laser beam. The thickness of the polymeric features can be varied from a few nanometers to over a micron.

  2. EFFECTS OF TRITIUM GAS EXPOSURE ON ELECTRICALLY CONDUCTING POLYMERS

    SciTech Connect (OSTI)

    Kane, M.; Clark, E.; Lascola, R.

    2009-12-16T23:59:59.000Z

    Effects of beta (tritium) and gamma irradiation on the surface electrical conductivity of two types of conducting polymer films are documented to determine their potential use as a sensing and surveillance device for the tritium facility. It was shown that surface conductivity was significantly reduced by irradiation with both gamma and tritium gas. In order to compare the results from the two radiation sources, an approximate dose equivalence was calculated. The materials were also sensitive to small radiation doses (<10{sup 5} rad), showing that there is a measurable response to relatively small total doses of tritium gas. Spectroscopy was also used to confirm the mechanism by which this sensing device would operate in order to calibrate this sensor for potential use. It was determined that one material (polyaniline) was very sensitive to oxidation while the other material (PEDOT-PSS) was not. However, polyaniline provided the best response as a sensing material, and it is suggested that an oxygen-impermeable, radiation-transparent coating be applied to this material for future device prototype fabrication. A great deal of interest has developed in recent years in the area of conducting polymers due to the high levels of conductivity that can be achieved, some comparable to that of metals [Gerard 2002]. Additionally, the desirable physical and chemical properties of a polymer are retained and can be exploited for various applications, including light emitting diodes (LED), anti-static packaging, electronic coatings, and sensors. The electron transfer mechanism is generally accepted as one of electron 'hopping' through delocalized electrons in the conjugated backbone, although other mechanisms have been proposed based on the type of polymer and dopant [Inzelt 2000, Gerard 2002]. The conducting polymer polyaniline (PANi) is of particular interest because there are extensive studies on the modulation of the conductivity by changing either the oxidation state of the main backbone chain, or by protonation of the imine groups [de Acevedo, 1999]. There are several types of radiation sensors commercially available, including ionization chambers, geiger counters, proportional counters, scintillators and solid state detectors. Each type has advantages, although many of these sensors require expensive electronics for signal amplification, are large and bulky, have limited battery life or require expensive materials for fabrication. A radiation sensor constructed of a polymeric material could be flexible, light, and the geometry designed to suit the application. Very simple and inexpensive electronics would be necessary to measure the change in conductivity with exposure to radiation and provide an alarm system when a set change of conductivity occurs in the sensor that corresponds to a predetermined radiation dose having been absorbed by the polymer. The advantages of using a polymeric sensor of this type rather than those currently in use are the flexibility of sensor geometry and relatively low cost. It is anticipated that these sensors can be made small enough for glovebox applications or have the ability to monitor the air tritium levels in places where a traditional monitor cannot be placed. There have been a few studies on the changes in conductivity of polyaniline specifically for radiation detection [de Acevedo, 1999; Lima Pacheco, 2003], but there have been no reports on the effects of tritium (beta radiation) on conducting polymers, such as polyaniline or polythiophene. The direct implementation of conducting polymers as radiation sensor materials has not yet been commercialized due to differing responses with total dose, dose rate, etc. Some have reported a large increase in the surface conductivity with radiation dose while others report a marked decrease in conductive properties; these differing observations may reflect the competing mechanisms of chain scission and cross-linking. However, it is clear that the radiation dose effects on conducting polymers must be fully understood before these materials can be used

  3. Polymer escape from a confining potential

    E-Print Network [OSTI]

    Harri Mökkönen; Timo Ikonen; Tapio Ala-Nissila; Hannes Jónsson

    2015-03-26T23:59:59.000Z

    The rate of escape of polymers from a two-dimensionally confining potential well has been evaluated using self-avoiding as well as ideal chain representations of varying length, up to 80 beads. Long timescale Langevin trajectories were calculated using the path integral hyperdynamics method to evaluate the escape rate. A minimum is found in the rate for self-avoiding polymers of intermediate length while the escape rate decreases monotonically with polymer length for ideal polymers. The increase in the rate for long, self-avoiding polymers is ascribed to crowding in the potential well which reduces the free energy escape barrier. An effective potential curve obtained using the centroid as an independent variable was evaluated by thermodynamic averaging and Kramers rate theory then applied to estimate the escape rate. While the qualitative features are well reproduced by this approach, it significantly overestimates the rate, especially for the longer polymers. The reason for this is illustrated by constructing a two-dimensional effective energy surface using the radius of gyration as well as the centroid as controlled variables. This shows that the description of a transition state dividing surface using only the centroid fails to confine the system to the region corresponding to the free energy barrier and this problem becomes more pronounced the longer the polymer is. A proper definition of a transition state for polymer escape needs to take into account the shape as well as the location of the polymer.

  4. Localized domain patterns in complex polymers

    E-Print Network [OSTI]

    Localized domain patterns in complex polymers abstract. Block copolymers are macromolecules that can form variety of microstructures as a result of incomplete

  5. Conducting polymer actuator enhancement through microstructuring

    E-Print Network [OSTI]

    Pillai, Priam Vasudevan

    2007-01-01T23:59:59.000Z

    Electroactive conducting polymers, such as polypyrrole, polyaniline, and polythiophenes are currently studied as novel biologically inspired actuators. The actuation mechanisms in these materials are based on the diffusion ...

  6. EFFECTS OF TRITIUM GAS EXPOSURE ON POLYMERS

    SciTech Connect (OSTI)

    Clark, E.; Fox, E.; Kane, M.; Staack, G.

    2011-01-07T23:59:59.000Z

    Effects of tritium gas exposure on various polymers have been studied over the last several years. Despite the deleterious effects of beta exposure on many material properties, structural polymers continued to be used in tritium systems. Improved understanding of the tritium effects will allow more resistant materials to be selected. Currently polymers find use mainly in tritium gas sealing applications (eg. valve stem tips, O-rings). Future uses being evaluated including polymeric based cracking of tritiated water, and polymer-based sensors of tritium.

  7. Fabrication and characterization of conducting polymer microwires

    E-Print Network [OSTI]

    Saez, Miguel Angel

    2009-01-01T23:59:59.000Z

    Flexible microwires fabricated from conducting polymers have a wide range of potential applications, including smart textiles that incorporate sensing, actuation, and data processing. The development of garments that ...

  8. Conformational properties of polymers in anisotropic environments

    E-Print Network [OSTI]

    K. Haydukivska; V. Blavatska

    2014-07-11T23:59:59.000Z

    We analyze the conformational properties of polymer macromolecules in solutions in presence of extended structural obstacles of (fractal) dimension $\\varepsilon_d$ causing the anisotropy of environment. Applying the pruned-enriched Rosenbluth method (PERM), we obtain numerical estimates for scaling exponents and universal shape parameters of polymers in such environments for a wide range $0polymer renormalization scheme. Both numerical and analytical studies qualitatively confirm the existence of two characteristic length scales of polymer chain in directions parallel and perpendicular to the extended defects.

  9. Ab initio treatment of electron correlations in polymers: Lithium hydride chain and beryllium hydride polymer

    E-Print Network [OSTI]

    Birkenheuer, Uwe

    Ab initio treatment of electron correlations in polymers: Lithium hydride chain and berylliumH and beryllium hydride Be2H4 . First, employing a Wannier-function-based approach, the systems are studiedH and the beryllium hydride polymer Be2H4 . As a simple, but due to its ionic character, non- trivial model polymer

  10. Heat Transfer Study of Polymer Solutions with Different Rigidities

    E-Print Network [OSTI]

    Huang, Yao

    2014-05-08T23:59:59.000Z

    rigidities. A mathematic method was introduced to model the rigidity of polymer chain's effect on the dynamic viscosity of dilute polymer solution. Results were also obtained for the dilute polymer solutions under both hydro-dynamically developing and hydro...

  11. Segregated Network Polymer-Carbon Nanotubes Composites For Thermoelectrics 

    E-Print Network [OSTI]

    Kim, Dasaroyong

    2010-10-12T23:59:59.000Z

    in polymer technology, particularly nanomaterial-polymer composites, can bring them into degenerate semiconductor or metallic regimes by incorporating a small amount of conductive filler. I demonstrate that such polymer nanocomposites can be viable for light...

  12. Conjugated Polymer Design and Engineering for Organic Electronics

    E-Print Network [OSTI]

    Woo, Claire Hoi Kar

    2011-01-01T23:59:59.000Z

    G. ; Reynaers, H. Polymer, 1989, 30, 2164-2169. (41) Alamo,M. M. ; Janssen, R. A. J. Polymer 2009, 50, 4564-4570. (14)Conductive Molecules and Polymers, Volume 2, Conductive

  13. Polymer dynamics in random flow with mean shear K. Turitsyn

    E-Print Network [OSTI]

    Fominov, Yakov

    Polymer dynamics in random flow with mean shear K. Turitsyn Landau Institute for theoretical;Outline · Motivation: Elastic turbulence · Experimental setup · Flow and polymer models · Results: 1. Angular statistics 2. Polymer elongation distribution · Conclusion #12;Elastic Turbulence Elastic

  14. On healable polymers and fiber-reinforced composites

    E-Print Network [OSTI]

    Nielsen, Christian Eric

    2012-01-01T23:59:59.000Z

    of crack healing in polymers. J Appl Phys Wu DY, Meure S,Single component healable polymer [proposal]. Los Angeles,and valuable healable polymer samples. Outside of UCSD, Dr.

  15. Solution Self-Assembly of Sequence Specific Biomimetic Polymers

    E-Print Network [OSTI]

    Murnen, Hannah

    2012-01-01T23:59:59.000Z

    from sequence-specific peptoid polymers. Nat. Mater. 2010, 9from sequence-specific peptoid polymers. Nat. Mater. 2010, 9in a folded nonbiological polymer. J. Am. Chem. Soc. Patch,

  16. NANOCOMPOSITE BASED STRUCTURAL HEALTH MONITORING APPROACHES FOR FIBRE REINFORCED POLYMERS

    E-Print Network [OSTI]

    Boyer, Edmond

    NANOCOMPOSITE BASED STRUCTURAL HEALTH MONITORING APPROACHES FOR FIBRE REINFORCED POLYMERS for Polymers and Composites, Denickestr. 15, 21073 Hamburg, Germany 2 Physics Department, Faculty of Science reinforced polymer (FRP) structures in many industrial branches. Different approaches for Structural Health

  17. Ris-PhD-Report Thermocleavable Conjugated Polymers -

    E-Print Network [OSTI]

    Risø-PhD-Report Thermocleavable Conjugated Polymers - Synthesis and photovoltaic applications Martin Helgesen Risø-PhD-54(EN) October 2009 #12;Thermocleavable Conjugated Polymers Synthesis, University of Copenhagen #12;Author: Martin Helgesen able Conjugated Polymers ­ Synthesis and photovoltaic

  18. Nanostructured polymer composites for electronics and sensor applications

    E-Print Network [OSTI]

    Fisher, Frank

    Nanostructured polymer composites for electronics and sensor applications Wednesday November 10 Michigan University, Kalamazoo, MI Nanostructured composites based on polymer matrix and carbon nanotubes (CNT), metallic nanoparticles and polymer core-shell latex systems will play a critical role

  19. KrF- and ArF-excimer-laser-induced absorption in silica glasses produced by melting synthetic silica powder

    SciTech Connect (OSTI)

    Kuzuu, Nobu; Sasaki, Toshiya; Kojima, Tatsuya [Department of Applied Physics, University of Fukui, 3-9-1 Bunkyo, Fukui-shi, Fukui 910-8507 (Japan); Tanaka, Jun-ichiro; Nakamura, Takayuki; Horikoshi, Hideharu [Tosoh SGM Corp., 4555 Kaisei-cho, Shunan-shi, Yamaguchi 746-0006 (Japan)

    2013-07-07T23:59:59.000Z

    KrF- and ArF-excimer-laser-induced absorption of silica glasses produced by electric melting and flame fusion of synthetic silica powder were investigated. The growth of KrF-laser-induced absorption was more gradual than that of ArF-laser-induced absorption. Induced absorption spectra exhibited a peak at about 5.8 eV, of which the position and width differed slightly among samples and laser species. Widths of ArF-laser-induced absorption spectra were wider than those of KrF-laser-induced spectra. KrF-laser-induced absorption is reproducible by two Gaussian absorption bands peaking at 5.80 eV with full width at half maximum (FWHM) of 0.62 eV and at 6.50 eV with FWHM of 0.74 eV. For reproduction of ArF-laser-induced absorption, Gaussian bands at 5.41 eV with FWHM of 0.62 eV was necessary in addition to components used for reproducing KrF-laser-induced absorption. Based on the discussion of the change of defect structures evaluated from change of absorption components, we proposed that the precursor of the 5.8-eV band ascribed to E Prime center ({identical_to}Si{center_dot}) is {identical_to}Si-H HO-Si{identical_to} structures formed by the reaction between strained Si-O-Si bonds and interstitial H{sub 2} molecules during the irradiation.

  20. Synthesis and characterization of redox polymers of (M(4-vinyl-4 prime -methyl-2,2 prime -bipyridine) sub 3 )(PF sub 6 ) sub 2 (M = Ru, Os)

    SciTech Connect (OSTI)

    Bommarito, S.L.; Lowery-Bretz, S.P.; Abruna, H.D. (Cornell Univ., Ithaca, NY (United States))

    1992-02-05T23:59:59.000Z

    The authors have prepared polymers of (M(vbpy){sub 3}(PF{sub 6}){sub 2}) (M = Ru, Os) (vbpy = 4-vinyl-4{prime}-methyl-2,2{prime}-bipyridine) in solution via free-radical polymerization and fractionated them according to molecular weight using size exclusion chromatography. Different fractions have been characterized by electrochemical and spectroscopic means. The authors find that whereas for the osmium containing polymers the relative polymer size varies in proportion to the number of vinyl groups consumed during the polymerization reaction, the same is not true for the analogous ruthenium polymers. In addition, the emission energy of both the ruthenium and osmium polymers is also related to the concentration of residual vinyl groups in the polymer. Upon polymerization, there is a shift in the emission toward higher energies. Electrochemically determined diffusion coefficients are consistent with the relative size of the various fractions.

  1. Dynamics of femtosecond laser absorption of fused silica in the ablation regime

    SciTech Connect (OSTI)

    Lebugle, M., E-mail: lebugle@lp3.univ-mrs.fr; Sanner, N.; Varkentina, N.; Sentis, M.; Utéza, O. [Aix Marseille Université, CNRS, LP3 UMR 7341, 13288 Marseille (France)

    2014-08-14T23:59:59.000Z

    We investigate the ultrafast absorption dynamics of fused silica irradiated by a single 500?fs laser pulse in the context of micromachining applications. A 60-fs-resolution pump-probe experiment that measures the reflectivity and transmissivity of the target under excitation is developed to reveal the evolution of plasma absorption. Above the ablation threshold, an overcritical plasma with highly non-equilibrium conditions is evidenced in a thin layer at the surface. The maximum electron density is reached at a delay of 0.5?ps after the peak of the pump pulse, which is a strong indication of the occurrence of electronic avalanche. The results are further analyzed to determine the actual feedback of the evolution of the optical properties of the material on the pump pulse. We introduce an important new quantity, namely, the duration of absorption of the laser by the created plasma, corresponding to the actual timespan of laser absorption by inverse Bremsstrahlung. Our results indicate an increasing contribution of plasma absorption to the total material absorption upon raising the excitation fluence above the ablation threshold. The role of transient optical properties during the energy deposition stage is characterized and our results emphasize the necessity to take it into account for better understanding and control of femtosecond laser-dielectrics interaction.

  2. ORNL devises recipe to fine-tune diameter of silica rods | ornl...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the stage for advances in anti-reflective solar cells, computer monitors, TV screens, eye glasses and more. The goal of fabricating fixed-size one-dimensional silica structures...

  3. Method for inhibiting silica precipitation and scaling in geothermal flow systems

    DOE Patents [OSTI]

    Harrar, J.E.; Lorensen, L.E.; Locke, F.E.

    1980-06-13T23:59:59.000Z

    A method for inhibiting silica scaling and precipitation in geothermal flow systems by on-line injection of low concentrations of cationic nitrogen-containing compounds, particularly polymeric imines, polymeric amines, and quaternary ammonium compounds is described.

  4. Method for inhibiting silica precipitation and scaling in geothermal flow systems

    DOE Patents [OSTI]

    Harrar, Jackson E. (Castro Valley, CA); Lorensen, Lyman E. (Orinda, CA); Locke, Frank E. (Lafayette, CA)

    1982-01-01T23:59:59.000Z

    A method for inhibiting silica scaling and precipitation in geothermal flow systems by on-line injection of low concentrations of cationic nitrogen-containing compounds, particularly polymeric imines, polymeric amines, and quaternary ammonium compounds.

  5. Study of the Behavior of a Commercial Scale Inhibitor on Silica Sand

    E-Print Network [OSTI]

    Vaca Bustamante, Victor

    2010-12-14T23:59:59.000Z

    squeeze lifetimes in order to minimize the number of treatments, thus reducing the cost. The objective of this thesis is to study the adsorption of the commercial scale inhibitor SI onto silica sand. By investigating this intrinsic phenomenon, an optimized...

  6. Silica stabilized iron particles toward anti-corrosion magnetic polyurethane nanocomposites

    E-Print Network [OSTI]

    Guo, John Zhanhu

    Silica stabilized iron particles toward anti-corrosion magnetic polyurethane nanocomposites Jiahua with various materials to form core-shell structures results in the new hybrid materials, which can be used

  7. Laser-induced fluorescence of fused silica irradiated by ArF excimer laser

    SciTech Connect (OSTI)

    Zhang Haibo [Shanghai Key Laboratory of All Solid-state Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai 201800 (China); Graduate University of Chinese Academy of Science, Beijing 100049 (China); Yuan Zhijun; Zhou Jun; Dong Jingxing; Wei Yunrong; Lou Qihong [Shanghai Key Laboratory of All Solid-state Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai 201800 (China)

    2011-07-01T23:59:59.000Z

    Laser-induced fluorescence (LIF) of high-purity fused silica irradiated by ArF excimer laser is studied experimentally. LIF bands of the fused silica centered at 281 nm, 478 nm, and 650 nm are observed simultaneously. Furthermore, the angular distribution of the three fluorescence peaks is examined. Microscopic image of the laser modified fused silica indicates that scattering of the generated fluorescence by laser-induced damage sites is the main reason for the angular distribution of LIF signals. Finally, the dependence of LIF signals intensities of the fused silica on laser power densities is presented. LIF signals show a squared power density dependence, which indicates that laser-induced defects are formed mainly via two-photon absorption processes.

  8. Structure-Function Relationships in Semiconducting Polymers for Organic Photovoltaics

    E-Print Network [OSTI]

    Kavulak, David Fredric Joel

    2010-01-01T23:59:59.000Z

    properties for organic photovoltaics (OPVs). Space-chargePolymers for Organic Photovoltaics By David Fredric JoelPolymers for Organic Photovoltaics by David Fredric Joel

  9. Development of Polymer Electrolytes for Advanced Lithium Batteries...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Polymer Electrolytes for Advanced Lithium Batteries Development of Polymer Electrolytes for Advanced Lithium Batteries 2013 DOE Hydrogen and Fuel Cells Program and Vehicle...

  10. High-Voltage Solid Polymer Batteries for Electric Drive Vehicles...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Voltage Solid Polymer Batteries for Electric Drive Vehicles High-Voltage Solid Polymer Batteries for Electric Drive Vehicles 2012 DOE Hydrogen and Fuel Cells Program and...

  11. Carrier heating in disordered conjugated polymers in electric field

    E-Print Network [OSTI]

    Vukmirovic, Nenad

    2010-01-01T23:59:59.000Z

    Carrier heating in disordered conjugated polymers inand the e?ect of carrier heating in disordered conjugatedinto the e?ect of carrier heating in conjugated polymers

  12. Development of a Low Cost Ultra Specular Advanced Polymer Film...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Development of a Low Cost Ultra Specular Advanced Polymer Film Solar Reflector Development of a Low Cost Ultra Specular Advanced Polymer Film Solar Reflector This presentation was...

  13. Modeling Cold Start in a Polymer-Electrolyte Fuel Cell

    E-Print Network [OSTI]

    Balliet, Ryan

    2010-01-01T23:59:59.000Z

    conditions used for fuel—cell simulations. 3.12 Values usedin Polymer Electrolyte Fuel Cells — II. Parametric Study,”of Polymer Electrolyte Fuel Cells,” Electrochimica Acta, 53,

  14. Controlled Self Assembly of Conjugated Polymer Containing Block Copolymers

    E-Print Network [OSTI]

    McCulloch, Bryan

    2012-01-01T23:59:59.000Z

    in dye/polymer blend photovoltaic cells. Advanced MaterialsA. J. , Polymer Photovoltaic Cells - Enhanced Efficiencies2-Layer Organic Photovoltaic Cell. Applied Physics Letters

  15. FY 2008 Progress Report for Lightweighting Materials - 8. Polymer...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    8. Polymer Composites Research and Development FY 2008 Progress Report for Lightweighting Materials - 8. Polymer Composites Research and Development Lightweighting Materials...

  16. FY 2009 Progress Report for Lightweighting Materials - 8. Polymer...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    8. Polymer Composites Research and Development FY 2009 Progress Report for Lightweighting Materials - 8. Polymer Composites Research and Development The primary Lightweight...

  17. Structure and Dynamics of Polymer Nanocomposites by Grazing-Incidence...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Structure and Dynamics of Polymer Nanocomposites by Grazing-Incidence X-Ray Techniques (Presentation) Structure and Dynamics of Polymer Nanocomposites by Grazing-Incidence X-Ray...

  18. Fiber Reinforced Polymer Composite Manufacturing - RFI Part 2...

    Broader source: Energy.gov (indexed) [DOE]

    1056 More Documents & Publications Fiber Reinforced Polymer Composite Manufacturing Workshop Fiber Reinforced Polymer Composite Manufacturing - RFI DE-FOA-0000980: Summary of...

  19. Atomizing apparatus for making polymer and metal powders and whiskers

    DOE Patents [OSTI]

    Otaigbe, Joshua U. (Ames, IA); McAvoy, Jon M. (Moline, IL); Anderson, Iver E. (Ames, IA); Ting, Jason (Ames, IA); Mi, Jia (Pittsburgh, PA); Terpstra, Robert (Ames, IA)

    2003-03-18T23:59:59.000Z

    Method for making polymer particulates, such as spherical powder and whiskers, by melting a polymer material under conditions to avoid thermal degradation of the polymer material, atomizing the melt using gas jet means in a manner to form atomized droplets, and cooling the droplets to form polymer particulates, which are collected for further processing. Atomization parameters can be controlled to produce polymer particulates with controlled particle shape, particle size, and particle size distribution. For example, atomization parameters can be controlled to produce spherical polymer powders, polymer whiskers, and combinations of spherical powders and whiskers. Atomizing apparatus also is provided for atoomizing polymer and metallic materials.

  20. Phosphate-Containing Polyethylene Glycol Polymers Prevent Lethal...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Phosphate-Containing Polyethylene Glycol Polymers Prevent Lethal Sepsis by Multidrug-Resistant Pathogens. Phosphate-Containing Polyethylene Glycol Polymers Prevent Lethal Sepsis by...

  1. New Polymer Architectures for Imidazole Solvating groups, Anion...

    Broader source: Energy.gov (indexed) [DOE]

    New Polymer Architectures for Imidazole Solvating groups, Anion Mobility and Flexibility New Polymer Architectures for Imidazole Solvating groups, Anion Mobility and Flexibility...

  2. High Temperature Thin Film Polymer Dielectric Based Capacitors...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Temperature Thin Film Polymer Dielectric Based Capacitors for HEV Power Electronic Systems High Temperature Thin Film Polymer Dielectric Based Capacitors for HEV Power...

  3. Haverford Researchers Create Carbon Dioxide-Separating Polymer

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Haverford College Researchers Create Carbon Dioxide-Separating Polymer Haverford College Researchers Create Carbon Dioxide-Separating Polymer August 1, 2012 | Tags: Basic Energy...

  4. acid polymers highly: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of Highly Porous Catalytic Layers for Polymer Electrolyte Fuel Cell Based on Carbon Aerogels Physics Websites Summary: Synthesis of Highly Porous Catalytic Layers for Polymer...

  5. Property Prediction Tools for Tailored Polymer Composite Structures...

    Energy Savers [EERE]

    2.pdf More Documents & Publications Property Prediction Tools for Tailored Polymer Composite Structures Engineering Property Prediction Tools for Tailored Polymer Composite...

  6. Property Prediction Tools for Tailored Polymer Composite Structures...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1.pdf More Documents & Publications Engineering Property Prediction Tools for Tailored Polymer Composite Structures Engineering Property Prediction Tools for Tailored Polymer...

  7. Highly Stable Trypsin-Aggregate Coatings on Polymer Nanofibers...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stable Trypsin-Aggregate Coatings on Polymer Nanofibers for Repeated Protein Digestion. Highly Stable Trypsin-Aggregate Coatings on Polymer Nanofibers for Repeated Protein...

  8. Mitigating Breakdown in High Energy Density Perovskite Polymer...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors 2012...

  9. Luminescent studies of fluorescent chromophore-doped silica aerogels for flat panel display applications

    SciTech Connect (OSTI)

    Glauser, S.A.C. [California Univ., Davis, CA (United States). Dept. of Applied Science; Lee, H.W.H. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01T23:59:59.000Z

    The remarkable optical and electronic properties of doped and undoped silica aerogels establish their utility as unique, mulitfunctional host materials for fluorescent dyes and other luminescent materials for display and imaging applications. We present results on the photoluminescence, absorption, and photoluminescence excitation spectra of undoped silica aerogels and aerogels doped with Er{sup 3+}, rhodamine 6G (R6G), and fluorescein. 4 refs., 12 figs.

  10. Sidestream treatment of high silica cooling water and reverse osmosis desalination in geothermal power generation

    SciTech Connect (OSTI)

    Mindler, A.B.; Bateman, S.T.

    1981-01-19T23:59:59.000Z

    Bench scale and pilot plant test work has been performed on cooling water for silica reduction and water reuse, at DOE's Raft River Geothermal Site, Malta, Idaho in cooperation with EG and G (Idaho), Inc. Technical supervision was by Permutit. A novel process of rusting iron shavings was found effective and economical in reducing silica to less than 20 mg/l. Reverse Osmosis was investigated for water reuse after pretreatment and ion exchange softening.

  11. Tandem Polymer Solar Cells Featuring a Spectrally Matched Low-Bandgap Polymer

    SciTech Connect (OSTI)

    Dou, L.; You, J.; Yang, J.; Chen, C. C.; He, Y.; Murase, S.; Moriarty, T.; Emery, K.; Li, G.; Yang, Y.

    2012-03-01T23:59:59.000Z

    Tandem solar cells provide an effective way to harvest a broader spectrum of solar radiation by combining two or more solar cells with different absorption bands. However, for polymer solar cells, the performance of tandem devices lags behind single-layer solar cells mainly due to the lack of a suitable low-bandgap polymer. Here, we demonstrate highly efficient single and tandem polymer solar cells featuring a low-bandgap conjugated polymer (PBDTT-DPP: bandgap, {approx}1.44 eV). A single-layer device based on the polymer provides a power conversion efficiency of {approx}6%. When the polymer is applied to tandem solar cells, a power conversion efficiency of 8.62% is achieved, which is, to the best of our knowledge, the highest certified efficiency for a polymer solar cell to date.

  12. Facilitation of polymer looping and giant polymer diffusivity in crowded solutions of active particles

    E-Print Network [OSTI]

    Shin, J; Kim, W K; Metzler, R

    2015-01-01T23:59:59.000Z

    We study the dynamics of polymer chains in a bath of self-propelled particles (SPP) by extensive Langevin dynamics simulations in a two dimensional system. Specifically, we analyse the polymer looping properties versus the SPP activity and investigate how the presence of the active particles alters the chain conformational statistics. We find that SPPs tend to extend flexible polymer chains while they rather compactify stiffer semiflexible polymers, in agreement with previous results. Here we show that larger activities of SPPs yield a higher effective temperature of the bath and thus facilitate looping kinetics of a passive polymer chain. We explicitly compute the looping probability and looping time in a wide range of the model parameters. We also analyse the motion of a monomeric tracer particle and the polymer's centre of mass in the presence of the active particles in terms of the time averaged mean squared displacement, revealing a giant diffusivity enhancement for the polymer chain via SPP pooling. Our...

  13. Fuel cell electrolyte membrane with basic polymer

    DOE Patents [OSTI]

    Larson, James M.; Pham, Phat T.; Frey, Matthew H.; Hamrock, Steven J.; Haugen, Gregory M.; Lamanna, William M.

    2012-12-04T23:59:59.000Z

    The present invention is an electrolyte membrane comprising an acid and a basic polymer, where the acid is a low-volatile acid that is fluorinated and is either oligomeric or non-polymeric, and where the basic polymer is protonated by the acid and is stable to hydrolysis.

  14. ADSORPTION OF SEMIFLEXIBLE POLYMERS ON HOMOGENEOUS SURFACES

    E-Print Network [OSTI]

    Oro, Daniel

    ADSORPTION OF SEMIFLEXIBLE POLYMERS ON HOMOGENEOUS SURFACES K. Sumithra F G Theoretische Physik the problem of adsorption of a single semiflexible polymer chain on to a planar, homogeneous surface using off-lattice Monte Carlosimulations. Adsorption characteristics were studied at different temperatures for chains

  15. Anion-Conducting Polymer, Composition, and Membrane

    DOE Patents [OSTI]

    Pivovar, Bryan S. (Los Alamos, NM); Thorn, David L. (Los Alamos, NM)

    2008-10-21T23:59:59.000Z

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  16. Polymer surface treatment with particle beams

    DOE Patents [OSTI]

    Stinnett, R.W.; VanDevender, J.P.

    1999-05-04T23:59:59.000Z

    A polymer surface and near surface treatment process produced by irradiation with high energy particle beams is disclosed. The process is preferably implemented with pulsed ion beams. The process alters the chemical and mechanical properties of the polymer surface in a manner useful for a wide range of commercial applications. 16 figs.

  17. Multicolored Electrochromism in Polymers: Structures and Devices

    E-Print Network [OSTI]

    Tanner, David B.

    Multicolored Electrochromism in Polymers: Structures and Devices Avni A. Argun, Pierre-Henri Aubert May 12, 2004 A review of electrochromic (EC) polymers and their applications in absorption/transmission, reflective, and patterned electrochromic devices (ECDs) is presented. Fundamental properties of EC materials

  18. Shape memory polymer actuator and catheter

    DOE Patents [OSTI]

    Maitland, Duncan J. (Pleasant Hill, CA); Lee, Abraham P. (Walnut Creek, CA); Schumann, Daniel L. (Concord, CA); Matthews, Dennis L. (Moss Beach, CA); Decker, Derek E. (Byron, CA); Jungreis, Charles A. (Pittsburgh, PA)

    2007-11-06T23:59:59.000Z

    An actuator system is provided for acting upon a material in a vessel. The system includes an optical fiber and a shape memory polymer material operatively connected to the optical fiber. The shape memory polymer material is adapted to move from a first shape for moving through said vessel to a second shape where it can act upon said material.

  19. Shape memory polymer actuator and catheter

    SciTech Connect (OSTI)

    Maitland, Duncan J.; Lee, Abraham P.; Schumann, Daniel L.; Matthews, Dennis L.; Decker, Derek E.; Jungreis, Charles A.

    2004-05-25T23:59:59.000Z

    An actuator system is provided for acting upon a material in a vessel. The system includes an optical fiber and a shape memory polymer material operatively connected to the optical fiber. The shape memory polymer material is adapted to move from a first shape for moving through said vessel to a second shape where it can act upon said material.

  20. Fuel cell electrolyte membrane with basic polymer

    DOE Patents [OSTI]

    Larson, James M. (Saint Paul, MN); Pham, Phat T. (Little Canada, MN); Frey, Matthew H. (Cottage Grove, MN); Hamrock, Steven J. (Stillwater, MN); Haugen, Gregory M. (Edina, MN); Lamanna, William M. (Stillwater, MN)

    2010-11-23T23:59:59.000Z

    The present invention is an electrolyte membrane comprising an acid and a basic polymer, where the acid is a low-volatile acid that is fluorinated and is either oligomeric or non-polymeric, and where the basic polymer is protonated by the acid and is stable to hydrolysis.

  1. Application of conducting polymers to electroanalysis

    SciTech Connect (OSTI)

    Josowicz, M.A.

    1994-04-01T23:59:59.000Z

    Conducting polymers can be used as sensitive layers in chemical microsensors leading to new applications of theses devices. They offer the potential for developing material properties that are critical to the sensor sensitivity, selectivity and fabrication. The advantages and limitations of the use of thin polymer layers in electrochemical sensors are discussed.

  2. Silylene- and disilyleneacetylene polymers from trichloroethylene

    DOE Patents [OSTI]

    Barton, T.J.; Ijadi-Maghsoodi, S.

    1990-07-10T23:59:59.000Z

    Organosilane polymers having recurring silyleneacetylene and/or disilyleneacetylene units are prepared in a one-pot synthesis from trichloroethylene. Depending on the organic substituents (R and R[prime]), these polymers have useful film-forming properties, and are converted to the ceramic, silicon carbide upon heating in very uniform high yields. They can also be pulled into fibers.

  3. Field theoretic simulations of polymer nanocomposites

    SciTech Connect (OSTI)

    Koski, Jason; Chao, Huikuan; Riggleman, Robert A., E-mail: rrig@seas.upenn.edu [Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2013-12-28T23:59:59.000Z

    Polymer field theory has emerged as a powerful tool for describing the equilibrium phase behavior of complex polymer formulations, particularly when one is interested in the thermodynamics of dense polymer melts and solutions where the polymer chains can be accurately described using Gaussian models. However, there are many systems of interest where polymer field theory cannot be applied in such a straightforward manner, such as polymer nanocomposites. Current approaches for incorporating nanoparticles have been restricted to the mean-field level and often require approximations where it is unclear how to improve their accuracy. In this paper, we present a unified framework that enables the description of polymer nanocomposites using a field theoretic approach. This method enables straightforward simulations of the fully fluctuating field theory for polymer formulations containing spherical or anisotropic nanoparticles. We demonstrate our approach captures the correlations between particle positions, present results for spherical and cylindrical nanoparticles, and we explore the effect of the numerical parameters on the performance of our approach.

  4. Anion-conducting polymer, composition, and membrane

    DOE Patents [OSTI]

    Pivovar, Bryan S. (Los Alamos, NM); Thorn, David L. (Los Alamos, NM)

    2009-09-01T23:59:59.000Z

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  5. Anion-conducting polymer, composition, and membrane

    DOE Patents [OSTI]

    Pivovar, Bryan S. (Los Alamos, NM); Thorn, David L. (Los Alamos, NM)

    2010-12-07T23:59:59.000Z

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  6. Anion-conducting polymer, composition, and membrane

    DOE Patents [OSTI]

    Pivovar, Bryan S. (Los Alamos, NM); Thorn, David L. (Los Alamos, NM)

    2011-11-22T23:59:59.000Z

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  7. Experimental solution thermodynamics of a ternary solvent/polymer/solvent system by inverse gas chromatography / by Dominic Wai Wah Ching 

    E-Print Network [OSTI]

    Ching, Dominic Wai Wah

    1978-01-01T23:59:59.000Z

    of the composition and of the orientation parameter y, The negative values of gG (Table V) obtained from this ex- pression indicate that the polymer dissolves in the solvents at this temperature. Third, the orientation parameter y that was determined did not vary... of the requirement for the degree of MASTER OF SCIENCE August 1978 Major Subjects Chemical Engineering EXPERIMENTAL SOLUTION THERMODYNAMICS OF A TERNARY SOLVENT/POLYMER/SOLVENT SYSTEM BY INVERSE GAS CHROMATOGRAPHY A Thesis DOMINIC WAI WAH CHING Approved...

  8. Diffraction in Time of Polymer Particles

    E-Print Network [OSTI]

    A. Martín-Ruiz

    2014-06-13T23:59:59.000Z

    We study the quantum dynamics of a suddenly released beam of particles using a background independent (polymer) quantization scheme. We show that, in the first order of approximation, the low-energy polymer distribution converges to the standard quantum-mechanical result in a clear fashion, but also arises an additional small polymer correction term. We find that the high-energy polymer behaviour becomes predominant at short distances and short times. Numerical results are also presented. We find that particles whose wave functions satisfy the polymer wave equation do not exhibit the diffraction in time phenomena. The implementation of a lower bound to the possible resolution of times into the time-energy Heisenberg uncertainty relation is briefly discussed.

  9. Tunable hydrophilicity on a hydrophobic fluorocarbon polymer coating on silicon

    SciTech Connect (OSTI)

    Kolari, K.; Hokkanen, A. [VTT Information Technology, Tietotie 3, 02150 Espoo (Finland)

    2006-07-15T23:59:59.000Z

    An efficient, economic, reliable, and repeatable patterning procedure of hydrophobic surfaces was developed. A fluorocarbon polymer derived from the C{sub 4}F{sub 8} gas in an inductively coupled plasma etcher was used as the hydrophobic coating. For a subsequent patterning of hydrophilic apertures on the polymer, a short O{sub 2} plasma exposure through a silicon shadow mask was utilized. The overall hydrophilicity of the patterned surface can be tuned by the duration of the O{sub 2} plasma exposure, and also by the density and the size of the hydrophilic apertures. The laborious photolithography and tricky lift-off procedures are avoided. Optimization of the whole patterning process is explained thoroughly and supported with experimental data. The hydrophilic adhesion of the patterned polymer was evaluated with aqueous droplets, which were studied on matrices of the hydrophilic apertures of different sizes. The deposition parameters of the fluorocarbon polymer, the size of the droplet required to enable rolling on the patterned surface, and the duration of the O{sub 2} plasma exposure were considered as the main parameters. To determine the achievable resolution of the patterning procedure, the subsurface etching beneath the shadow mask was evaluated. The results show that a resolution of less than 10 {mu}m can be achieved. The simple hydrophilic patterning procedure described here can be used for the production of on-plane microfluidics, where a controlled adhesion or decohesion of 8-50 {mu}l droplets on the surface with a variable hydrophilicity from one location to another can be achieved.

  10. 2010 POLYMER PHYSICS - JUNE 27 - JULY 2, 2010

    SciTech Connect (OSTI)

    Karen Winey

    2010-07-02T23:59:59.000Z

    The 2010 Gordon Research Conference on Polymer Physics will provide outstanding lectures and discussions in this critical field that impacts every industrial sector from electronics to transportation to medicine to textiles to energy generation and storage. Fundamental topics range from mechanical properties of soft gels to new understanding in polymer crystallization to energy conversion and transmission to simulating polymer dynamics at the nanoscale. This international conference will feature 22 invited lectures, wherein the opening 10 minutes are specifically designed for a general polymer physics audience. In addition, poster sessions and informal activities provide ample opportunity to discuss the latest advances in polymer physics. The technical content of the meeting will include new twists on traditional polymer physics topics, recent advances in previously underrepresented topics, and emerging technologies enabled by polymer physics. Here is a partially listing of targeted topics: (1) electrically-active and light-responsive polymers and polymer-based materials used in energy conversion and storage; (2) polymers with hierarchical structures including supramolecular assemblies, ion-containing polymers, and self-assembled block polymers; (3) mechanical and rheological properties of soft materials, such as hydrogels, and of heterogeneous materials, particularly microphase separated polymers and polymer nanocomposites; and (4) crystallization of polymers in dilute solutions, polymer melts, and miscible polymer blends.

  11. Advances in inherently conducting polymers

    SciTech Connect (OSTI)

    Aldissi, M.

    1987-09-01T23:59:59.000Z

    The discovery of polyacetylene as the prototype material led to extensive research on its synythesis and characterization. The techniques that emerged as the most important and promising ones are those that dealt with molecular orientation and that resulted in conductivities almost as high as that of copper. The study of dozens of other materials followed. Interest in conducting polymers stems from their nonclassical optical and electronic properties as well as their potential technological applications. However, some of the factors currently limiting their use are the lack of long-term stability and the need to develop conventional low-cost techniques for easy processing. Therefore, research was extended toward solving these problems, and progress has been recently made in that direction. The synthesis of new materials such as stable and easily processable alkylthiophenes, water-soluble polymers, and multicomponent systems, including copolymers and composites, constitutes an important step forward in the area of synthetic metals. However, a full understanding of materials chemistry and properties requires more work in the years to come. Although, few small-scale applications have proven to be successful, long-term stability and applicability tests are needed before their commercial use becomes reality.

  12. Improving the Performance of P3HT-Fullerene Solar Cells with Side-Chain-Functionalized Poly(thiophene) Additives: A New Paradigm for Polymer Design

    E-Print Network [OSTI]

    Lobez, Jose M.

    The motivation of this study is to determine if small amounts of designer additives placed at the polymer–fullerene interface in bulk heterojunction (BHJ) solar cells can influence their performance. A series of AB-alternating ...

  13. Implantation conditions for diamond nanocrystal formation in amorphous silica

    SciTech Connect (OSTI)

    Buljan, Maja; Radovic, Iva Bogdanovic; Desnica, Uros V.; Ivanda, Mile; Jaksic, Milko [Ruder Boskovic Institute, P.O. Box 180, 10002 Zagreb (Croatia); Saguy, Cecile; Kalish, Rafi [Physics Department and Solid State Institute, Technion, Haifa 32000 (Israel); Djerdj, Igor [Department of Materials, Swiss Federal Institute of Technology (ETH) Zuerich, Wolfgang-Pauli-Str. 10, CH-8093 Zuerich (Switzerland); Tonejc, Andelka [Faculty of Science, Department of Physics, University of Zagreb, 10000 Zagreb (Croatia); Gamulin, Ozren [School of Medicine, Zagreb University, 10000 Zagreb (Croatia)

    2008-08-01T23:59:59.000Z

    We present a study of carbon ion implantation in amorphous silica, which, followed by annealing in a hydrogen-rich environment, leads to preferential formation of carbon nanocrystals with cubic diamond (c-diamond), face-centered cubic (n-diamond), or simple cubic (i-carbon) carbon crystal lattices. Two different annealing treatments were used: furnace annealing for 1 h and rapid thermal annealing for a brief period, which enables monitoring of early nucleation events. The influence of implanted dose and annealing type on carbon and hydrogen concentrations, clustering, and bonding were investigated. Rutherford backscattering, elastic recoil detection analysis, infrared spectroscopy, transmission electron microscopy, selected area electron diffraction, ultraviolet-visible absorption measurements, and Raman spectroscopy were used to study these carbon formations. These results, combined with the results of previous investigations on similar systems, show that preferential formation of different carbon phases (diamond, n-diamond, or i-carbon) depends on implantation energy, implantation dose, and annealing conditions. Diamond nanocrystals formed at a relatively low carbon volume density are achieved by deeper implantation and/or lower implanted dose. Higher volume densities led to n-diamond and finally to i-carbon crystal formation. This observed behavior is related to damage sites induced by implantation. The optical properties of different carbon nanocrystal phases were significantly different.

  14. Templated Control of Au nanospheres in Silica Nanowires

    SciTech Connect (OSTI)

    Tringe, J W; Vanamu, G; Zaidi, S H

    2007-03-15T23:59:59.000Z

    The formation of regularly-spaced metal nanostructures in selectively-placed insulating nanowires is an important step toward realization of a wide range of nano-scale electronic and opto-electronic devices. Here we report templated synthesis of Au nanospheres embedded in silica nanowires, with nanospheres consistently spaced with a period equal to three times their diameter. Under appropriate conditions, nanowires form exclusively on Si nanostructures because of enhanced local oxidation and reduced melting temperatures relative to templates with larger dimensions. We explain the spacing of the nanospheres with a general model based on a vapor-liquid-solid mechanism, in which an Au/Si alloy dendrite remains liquid in the nanotube until a critical Si concentration is achieved locally by silicon oxide-generated nanowire growth. Additional Si oxidation then locally reduces the surface energy of the Au-rich alloy by creating a new surface with minimum area inside of the nanotube. The isolated liquid domain subsequently evolves to become an Au nanosphere, and the process is repeated.

  15. Orientational ordering of short LC rods in an anisotropic liquid crystalline polymer glass

    E-Print Network [OSTI]

    Cao, Jianshu

    Orientational ordering of short LC rods in an anisotropic liquid crystalline polymer glass Lorin the glass transition is determined by field theory. Microscopic anisotropic interactions can align the LC the glass transition. Host anisotropic glass formers made of mesogens with side chains were studied recently

  16. Porous polymer film calcium ion chemical sensor and method of using the same

    DOE Patents [OSTI]

    Porter, M.D.; Chau, L.K.

    1991-02-12T23:59:59.000Z

    A method of measuring calcium ions is disclosed wherein a calcium sensitive reagent, calcichrome, is immobilized on a porous polymer film. The reaction of the calcium sensitive reagent to the Ca(II) is then measured and concentration determined as a function of the reaction. 1 figure.

  17. Poly(methylmethacrylate) adsorption onto flat substrates of glass and silica: Influence of water traces in solvent

    SciTech Connect (OSTI)

    Berquier, J. [Laboratoire CNRS-Saint-Gobain (UMR 125) 39, Quai Lucien Lefranc, F-93303 Aubervilliers Cedex

    1996-01-01T23:59:59.000Z

    The adsorbed amount of PMMA on flat glass and silica is measured by infrared external reflection. The effect on PMMA adsorption of water traces in solvent is emphasized: the adsorbed amount increases with the water concentration. Flat glass and silica are compared: on contrary of what is expected, adsorbed amount on glass is higher than on silica. This result is interpreted as due to the difference of behaviour between glass and silica with respect to water adsorption. {copyright} {ital 1996 American Institute of Physics.}

  18. Glass/polymer composites and methods of making

    DOE Patents [OSTI]

    Samuels, W. D. (Richland, WA); Exarhos, Gregory J. (Richland, WA)

    1995-01-01T23:59:59.000Z

    The present invention relates to new glass/polymer composites and methods for making them. More specifically, the invention is glass/polymer composites having phases that are at the molecular level and thereby practicably indistinguishable. The invention further discloses making molecular phase glass/polymer composites by mixing a glass and a polymer in a compatible solvent.

  19. ME 379M Polymer Nanoparticles ABET EC2000 syllabus

    E-Print Network [OSTI]

    Ben-Yakar, Adela

    ME 379M ­ Polymer Nanoparticles Page 1 ABET EC2000 syllabus ME 379M ­ Polymer Nanoparticles Spring 2010 Required or Elective: Elective 2008-2010 Catalog Data: Course Topics Vary: Polymer Nanoparticles Prerequisite(s): Basic undergraduate level of materials science background Textbook(s): J.H. Koo, Polymer

  20. POLYMER SURFACE & INTERFACE GROUP Department of Physics, University of Guelph

    E-Print Network [OSTI]

    Dutcher, John

    POLYMER SURFACE & INTERFACE GROUP Department of Physics, University of Guelph Guelph, Ontario N1G 2W1 RESEARCH FOCUS The primary focus of our work in the Polymer Surface & Interface Group is the physics of polymer and biopolymer thin films and interfaces. Both polymer and biopolymer films are very

  1. Semiflexible Polymers: Fundamental Theory and Applications in DNA Packaging

    E-Print Network [OSTI]

    Straight, Aaron

    Semiflexible Polymers: Fundamental Theory and Applications in DNA Packaging Thesis by Andrew James of perfectly flexible and perfectly rigid polymer chains; however, many polymers, for example DNA, are somewhere in between these two limiting cases. Such polymers are termed semiflexible, and their molecular

  2. Water-Soluble Polymers from Acid-Functionalized Norbornenes

    E-Print Network [OSTI]

    Tew, Gregory N.

    , STERLING F. ALFRED, AHMAD E. MADKOUR, GREGORY N. TEW Department of Polymer Science and Engineering

  3. Conductive inks for metalization in integrated polymer microsystems

    DOE Patents [OSTI]

    Davidson, James Courtney (Livermore, CA); Krulevitch, Peter A. (Pleasanton, CA); Maghribi, Mariam N. (Livermore, CA); Benett, William J. (Livermore, CA); Hamilton, Julie K. (Tracy, CA); Tovar, Armando R. (San Antonio, TX)

    2006-02-28T23:59:59.000Z

    A system of metalization in an integrated polymer microsystem. A flexible polymer substrate is provided and conductive ink is applied to the substrate. In one embodiment the flexible polymer substrate is silicone. In another embodiment the flexible polymer substrate comprises poly(dimethylsiloxane).

  4. The conformational evolution of elongated polymer solutions tailors the polarization of light-emission from organic nanofibers

    E-Print Network [OSTI]

    Andrea Camposeo; Israel Greenfeld; Francesco Tantussi; Maria Moffa; Francesco Fuso; Maria Allegrini; Eyal Zussman; Dario Pisignano

    2014-07-30T23:59:59.000Z

    Polymer fibers are currently exploited in tremendously important technologies. Their innovative properties are mainly determined by the behavior of the polymer macromolecules under the elongation induced by external mechanical or electrostatic forces, characterizing the fiber drawing process. Although enhanced physical properties were observed in polymer fibers produced under strong stretching conditions, studies of the process-induced nanoscale organization of the polymer molecules are not available, and most of fiber properties are still obtained on an empirical basis. Here we reveal the orientational properties of semiflexible polymers in electrospun nanofibers, which allow the polarization properties of active fibers to be finely controlled. Modeling and simulations of the conformational evolution of the polymer chains during electrostatic elongation of semidilute solutions demonstrate that the molecules stretch almost fully within less than 1 mm from jet start, increasing polymer axial orientation at the jet center. The nanoscale mapping of the local dichroism of individual fibers by polarized near-field optical microscopy unveils for the first time the presence of an internal spatial variation of the molecular order, namely the presence of a core with axially aligned molecules and a sheath with almost radially oriented molecules. These results allow important and specific fiber properties to be manipulated and tailored, as here demonstrated for the polarization of emitted light.

  5. Megahertz organic/polymer diodes

    DOE Patents [OSTI]

    Katz, Howard Edan; Sun, Jia; Pal, Nath Bhola

    2012-12-11T23:59:59.000Z

    Featured is an organic/polymer diode having a first layer composed essentially of one of an organic semiconductor material or a polymeric semiconductor material and a second layer formed on the first layer and being electrically coupled to the first layer such that current flows through the layers in one direction when a voltage is applied in one direction. The second layer is essentially composed of a material whose characteristics and properties are such that when formed on the first layer, the diode is capable of high frequency rectifications on the order of megahertz rectifications such as for example rectifications at one of above 100KHz, 500KhZ, IMHz, or 10 MHz. In further embodiments, the layers are arranged so as to be exposed to atmosphere.

  6. Confetti Ordering by Polymer Brushes

    E-Print Network [OSTI]

    Galen T. Pickett

    2015-05-23T23:59:59.000Z

    I consider the ordering of dilute platelet additives when incorporated into an end-grafted polymer brush. The competition between wetting interactions and the anisotropic stress environment of the interior of the brush causes these platelet additives to either remain suspended at the outer edge of the brush laying flat against the brush surface (as bits of confetti at rest on the ground), or to invade the interior of the brush in which case the platelets stand end-on and in some cases protrude above the outer edge of the brush. The orientation of the additives is controlled by the ratio of the diameter of the additive to the thickness of the bare brush, as well as the ratio of solvent-monomer and solvent-platelet interactions.

  7. Two glass transitions in miscible polymer blends?

    SciTech Connect (OSTI)

    Dudowicz, Jacek; Freed, Karl F. [The James Franck Institute and the Department of Chemistry, The University of Chicago, Chicago, Illinois 60637 (United States); Douglas, Jack F. [Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

    2014-06-28T23:59:59.000Z

    In contrast to mixtures of two small molecule fluids, miscible binary polymer blends often exhibit two structural relaxation times and two glass transition temperatures. Qualitative explanations postulate phenomenological models of local concentration enhancements due to chain connectivity in ideal, fully miscible systems. We develop a quantitative theory that explains qualitative trends in the dynamics of real miscible polymer blends which are never ideal mixtures. The theory is a synthesis of the lattice cluster theory of blend thermodynamics, the generalized entropy theory for glass-formation in polymer materials, and the Kirkwood-Buff theory for concentration fluctuations in binary mixtures.

  8. Conductor-polymer composite electrode materials

    DOE Patents [OSTI]

    Ginley, D.S.; Kurtz, S.R.; Smyrl, W.H.; Zeigler, J.M.

    1984-06-13T23:59:59.000Z

    A conductive composite material useful as an electrode, comprises a conductor and an organic polymer which is reversibly electrochemically dopable to change its electrical conductivity. Said polymer continuously surrounds the conductor in intimate electrical contact therewith and is prepared by electrochemical growth on said conductor or by reaction of its corresponding monomer(s) on said conductor which has been pre-impregnated or pre-coated with an activator for said polymerization. Amount of the conductor is sufficient to render the resultant composite electrically conductive even when the polymer is in an undoped insulating state.

  9. Redox polymer electrodes for advanced batteries

    DOE Patents [OSTI]

    Gregg, B.A.; Taylor, A.M.

    1998-11-24T23:59:59.000Z

    Advanced batteries having a long cycle lifetime are provided. More specifically, the present invention relates to electrodes made from redox polymer films and batteries in which either the positive electrode, the negative electrode, or both, comprise redox polymers. Suitable redox polymers for this purpose include pyridyl or polypyridyl complexes of transition metals like iron, ruthenium, osmium, chromium, tungsten and nickel; porphyrins (either free base or metallo derivatives); phthalocyanines (either free base or metallo derivatives); metal complexes of cyclams, such as tetraazacyclotetradecane; metal complexes of crown ethers and metallocenes such as ferrocene, cobaltocene and ruthenocene. 2 figs.

  10. Electrical condition monitoring method for polymers

    DOE Patents [OSTI]

    Watkins, Jr. Kenneth S. (Dahlonega, GA); Morris, Shelby J. (Hampton, VA); Masakowski, Daniel D. (Worcester, MA); Wong, Ching Ping (Duluth, GA); Luo, Shijian (Boise, ID)

    2010-02-16T23:59:59.000Z

    An electrical condition monitoring method utilizes measurement of electrical resistivity of a conductive composite degradation sensor to monitor environmentally induced degradation of a polymeric product such as insulated wire and cable. The degradation sensor comprises a polymeric matrix and conductive filler. The polymeric matrix may be a polymer used in the product, or it may be a polymer with degradation properties similar to that of a polymer used in the product. The method comprises a means for communicating the resistivity to a measuring instrument and a means to correlate resistivity of the degradation sensor with environmentally induced degradation of the product.

  11. Redox polymer electrodes for advanced batteries

    DOE Patents [OSTI]

    Gregg, Brian A. (Golden, CO); Taylor, A. Michael (Golden, CO)

    1998-01-01T23:59:59.000Z

    Advanced batteries having a long cycle lifetime are provided. More specifically, the present invention relates to electrodes made from redox polymer films and batteries in which either the positive electrode, the negative electrode, or both, comprise redox polymers. Suitable redox polymers for this purpose include pyridyl or polypyridyl complexes of transition metals like iron, ruthenium, osmium, chromium, tungsten and nickel; porphyrins (either free base or metallo derivatives); phthalocyanines (either free base or metallo derivatives); metal complexes of cyclams, such as tetraazacyclotetradecane; metal complexes of crown ethers and metallocenes such as ferrocene, cobaltocene and ruthenocene.

  12. Polymer-induced tubulation in lipid vesicles

    E-Print Network [OSTI]

    F. Campelo; A. Hernandez-Machado

    2008-04-21T23:59:59.000Z

    A mechanism of extraction of tubular membranes from a lipid vesicle is presented. A concentration gradient of anchoring amphiphilic polymers generates tubes from bud-like vesicle protrusions. We explain this mechanism in the framework of the Canham-Helfrich model. The energy profile is analytically calculated and a tube with a fixed length, corresponding to an energy minimum, is obtained in a certain regime of parameters. Further, using a phase-field model, we corroborate these results numerically. We obtain the growth of tubes when a polymer source is added, and the bud-like shape after removal of the polymer source, in accordance with recent experimental results.

  13. Porphyrin coordination polymer nanospheres and nanorods

    DOE Patents [OSTI]

    Wang, Zhongchun; Shelnutt, John A.; Medforth, Craig J.

    2012-12-04T23:59:59.000Z

    A porphyrin coordination polymer nanostructure comprising a network of pyridyl porphyrin molecules and coordinating metal ions coordinatively bound through the pyridyl groups. In some embodiments, the porphyrins are metalloporphyrins. A variety of nanostructures are formed by the network polymer, including nanospheres, polygonal nanostructures, nanorods, and nanofibers, depending on a variety of factors including coordination metal ion, porphyrin type, metal of the metalloporphyrin, and degree of agitation during nanostructure formation. Reduction of coordinating metal ions may be used to form metal nanoparticles on the coordination polymer nanostructure.

  14. Randomly charged polymers in porous environment

    E-Print Network [OSTI]

    V. Blavatska; C. von Ferber

    2013-11-22T23:59:59.000Z

    We study the conformational properties of charged polymers in a solvent in the presence of structural obstacles correlated according to a power law $\\sim x^{-a}$. We work within the continuous representation of a model of linear chain considered as a random sequence of charges $q_i=\\pm q_0$. Such a model captures the properties of polyampholytes -- heteropolymers comprising both positively and negatively charged monomers. We apply the direct polymer renormalization scheme and analyze the scaling behavior of charged polymers up to the first order of an $\\epsilon=6-d$, $\\delta=4-a$-expansion.

  15. Nonlinear elastic polymers in random flow

    E-Print Network [OSTI]

    M. Martins Afonso; D. Vincenzi

    2005-08-09T23:59:59.000Z

    Polymer stretching in random smooth flows is investigated within the framework of the FENE dumbbell model. The advecting flow is Gaussian and short-correlated in time. The stationary probability density function of polymer extension is derived exactly. The characteristic time needed for the system to attain the stationary regime is computed as a function of the Weissenberg number and the maximum length of polymers. The transient relaxation to the stationary regime is predicted to be exceptionally slow in the proximity of the coil-stretch transition.

  16. The Influences of Fiber Feature and Polymer Melt Index on Mechanical Properties of Sugarcane Fiber/Polymer

    E-Print Network [OSTI]

    The Influences of Fiber Feature and Polymer Melt Index on Mechanical Properties of Sugarcane Fiber/Polymer.interscience.wiley.com). ABSTRACT: The fiber characteristics (i.e., the fiber type, morphology, and dimension) and polymer melt flow sugarcane fiber/polymer composites, the HDPE resins with a low MFI value presented high tensile and impact

  17. Neutron and X-ray scattering experiments on lithium polymer electrolytes

    SciTech Connect (OSTI)

    Saboungi, M.L.; Price, D.L.

    1997-09-01T23:59:59.000Z

    The authors are carrying out structural, dynamical and transport measurements of lithium polymer electrolytes, in order to provide information needed to improve the performance of secondary lithium battery systems. Microscopically, they behave as liquids under conditions of practical interest. Development of batteries based on these materials has focused on rechargeable systems with intercalation/insertion cathodes and lithium or lithium-containing materials as anodes. The electrolytes are generally composites of a polyethylene oxide (PEO) or another modified polyether and a salt such as LiClO{sub 4}, LiAsF{sub 6} or LiCF{sub 3}SO{sub 3}. Research on electrolyte materials for lithium batteries has focused on synthesis, characterization, and development of practical devices. Some characterization work has been carried out to determine the properties of the ion polymer and ion interactions, principally through spectroscopic, thermodynamic and transport measurements. It is generally believed that ionic conduction is a property of the amorphous phase of these materials. It is also believed that ion association, ion polymer interactions and local relaxations of the polymer strongly influence the ionic mobility. However, much about the nature of the charge carriers, the ion association processes, and the ion polymer interactions and the role that these play in the ionic conductivity of the electrolytes remains unknown. The authors have initiated a combined experimental and theoretical study of the structure and dynamics of lithium polymer electrolytes. They plan to investigate the effects of the polymer host on ion solvation and the attendant effects of ion pairing, which affect the ionic transport in these systems.

  18. NiO-silica based nanostructured materials obtained by microemulsion assisted sol-gel procedure

    SciTech Connect (OSTI)

    Mihaly, M.; Comanescu, A.F. [University POLITEHNICA Bucharest, Faculty of Applied Chemistry and Materials Science, 1 Polizu, 011061 Bucharest (Romania)] [University POLITEHNICA Bucharest, Faculty of Applied Chemistry and Materials Science, 1 Polizu, 011061 Bucharest (Romania); Rogozea, A.E. [ILIE MURGULESCU Institute of Physical Chemistry of the Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania)] [ILIE MURGULESCU Institute of Physical Chemistry of the Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Vasile, E. [METAV Research and Development, 31 C.A. Rosetti, 020011 Bucharest (Romania)] [METAV Research and Development, 31 C.A. Rosetti, 020011 Bucharest (Romania); Meghea, A., E-mail: a.meghea@gmail.com [University POLITEHNICA Bucharest, Faculty of Applied Chemistry and Materials Science, 1 Polizu, 011061 Bucharest (Romania)

    2011-10-15T23:59:59.000Z

    Graphical abstract: TEM micrograph of NiO/SiO{sub 2} nanoparticles. Highlights: {yields} Microemulsion assisted sol-gel procedure for NiO silica nanomaterials synthesis. {yields} Controlling the size and shape of nanoparticles and avoiding their aggregation. {yields} Narrow band-gap semiconductors (energies <3 eV) absorbing VIS or near-UV light biologically and chemically inert semiconductors entrapping/coating in silica network. {yields} Low cost as the microemulsion is firstly used in water metallic cation extraction. -- Abstract: NiO-silica based materials have been synthesized by microemulsion assisted sol-gel procedure. The versatility of these soft nanotechnology techniques has been exploited in order to obtain different types of nanostructures, such as NiO nanoparticles, NiO silica coated nanoparticles and NiO embedded in silica matrix. These materials have been characterized by adequate structural and morphology techniques: DLS, HR-TEM/SAED, BET, AFM. Optical and semiconducting properties (band-gap values) of the synthesized materials have been quantified by means of VIS-NIR diffuse reflectance spectra, thus demonstrating their applicative potential in various electron transfer phenomena such as photocatalysis, electrochromic thin films, solid oxide fuel cells.

  19. Thickness controlled sol-gel silica films for plasmonic bio-sensing devices

    SciTech Connect (OSTI)

    Figus, Cristiana, E-mail: cristiana.figus@dsf.unica.it; Quochi, Francesco, E-mail: cristiana.figus@dsf.unica.it; Artizzu, Flavia, E-mail: cristiana.figus@dsf.unica.it; Saba, Michele, E-mail: cristiana.figus@dsf.unica.it; Marongiu, Daniela, E-mail: cristiana.figus@dsf.unica.it; Mura, Andrea; Bongiovanni, Giovanni [Dipartimento di Fisica - University of Cagliari, S.P. Km 0.7, I-09042 Monserrato (Canada) (Italy); Floris, Francesco; Marabelli, Franco; Patrini, Maddalena; Fornasari, Lucia [Dipartimento di Fisica - University of Pavia, Via Agostino Bassi 6, I-27100 Pavia (PV) (Italy); Pellacani, Paola; Valsesia, Andrea [Plasmore S.r.l. -Via Grazia Deledda 4, I-21020 Ranco (Vatican City State, Holy See) (Italy)

    2014-10-21T23:59:59.000Z

    Plasmonics has recently received considerable interest due to its potentiality in many fields as well as in nanobio-technology applications. In this regard, various strategies are required for modifying the surfaces of plasmonic nanostructures and to control their optical properties in view of interesting application such as bio-sensing, We report a simple method for depositing silica layers of controlled thickness on planar plasmonic structures. Tetraethoxysilane (TEOS) was used as silica precursor. The control of the silica layer thickness was obtained by optimizing the sol-gel method and dip-coating technique, in particular by properly tuning different parameters such as pH, solvent concentration, and withdrawal speed. The resulting films were characterized via atomic force microscopy (AFM), Fourier-transform (FT) spectroscopy, and spectroscopic ellipsometry (SE). Furthermore, by performing the analysis of surface plasmon resonances before and after the coating of the nanostructures, it was observed that the position of the resonance structures could be properly shifted by finely controlling the silica layer thickness. The effect of silica coating was assessed also in view of sensing applications, due to important advantages, such as surface protection of the plasmonic structure.

  20. Polymer Matrix Composites: A Perspective for a Special Issue of Polymer Reviews

    SciTech Connect (OSTI)

    Kessler, Michael R.

    2012-09-04T23:59:59.000Z

    Polymer matrix composites, with their high specific strength and stiffness, are used in a wide range of applications from large wind turbine blades to microelectronics. This perspective article provides a brief primer on polymer matrix composites, discusses some of their advantages and limitations, and describes a number of emerging trends in the field. In addition, it introduces four review articles on the topics of recent developments in carbon fibers, natural fiber reinforced composites, evaluation of the interface between the fiber reinforcement and polymer matrix, and carbon nanotube reinforced polymers.