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1

Formation of Metallic Copper Nanoparticles at the Soil-Root Interface  

NLE Websites -- All DOE Office Websites (Extended Search)

Formation of Metallic Copper Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Print Wednesday, 26 March 2008 00:00 The first commercial fungicide-the "Bordeaux mixture" of copper sulfate and lime-was used to fight downy mildew in French vineyards. The fungicide worked by catalyzing the production of free radicals that damage proteins and enzymes involved in cycling copper between Cu(I) and Cu(II) oxidation states in the cellular electron transport chain. However, not all fungi are sensitive to copper toxicity. Some, called mycorrhizae, which live underground in symbiosis with host plants through intracellular or extracellular colonization of their roots, are resistant, although it is not known why. A team from the CNRS and Université Joseph Fourier in Grenoble in collaboration with researchers at the University of Illinois at Chicago and in partnership with the French company Phytorestore has discovered a new form of copper-metallic nanoparticles-in the rhizosphere (soil-root interface) that may explain how mycorrhizal (symbiotic) fungi detoxify copper.

2

Formation of Metallic Copper Nanoparticles at the Soil-Root Interface  

NLE Websites -- All DOE Office Websites (Extended Search)

Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Print Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Print The first commercial fungicide-the "Bordeaux mixture" of copper sulfate and lime-was used to fight downy mildew in French vineyards. The fungicide worked by catalyzing the production of free radicals that damage proteins and enzymes involved in cycling copper between Cu(I) and Cu(II) oxidation states in the cellular electron transport chain. However, not all fungi are sensitive to copper toxicity. Some, called mycorrhizae, which live underground in symbiosis with host plants through intracellular or extracellular colonization of their roots, are resistant, although it is not known why. A team from the CNRS and Université Joseph Fourier in Grenoble in collaboration with researchers at the University of Illinois at Chicago and in partnership with the French company Phytorestore has discovered a new form of copper-metallic nanoparticles-in the rhizosphere (soil-root interface) that may explain how mycorrhizal (symbiotic) fungi detoxify copper.

3

Formation of Metallic Copper Nanoparticles at the Soil-Root Interface  

NLE Websites -- All DOE Office Websites (Extended Search)

Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Print Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Print The first commercial fungicide-the "Bordeaux mixture" of copper sulfate and lime-was used to fight downy mildew in French vineyards. The fungicide worked by catalyzing the production of free radicals that damage proteins and enzymes involved in cycling copper between Cu(I) and Cu(II) oxidation states in the cellular electron transport chain. However, not all fungi are sensitive to copper toxicity. Some, called mycorrhizae, which live underground in symbiosis with host plants through intracellular or extracellular colonization of their roots, are resistant, although it is not known why. A team from the CNRS and Université Joseph Fourier in Grenoble in collaboration with researchers at the University of Illinois at Chicago and in partnership with the French company Phytorestore has discovered a new form of copper-metallic nanoparticles-in the rhizosphere (soil-root interface) that may explain how mycorrhizal (symbiotic) fungi detoxify copper.

4

Formation of Metallic Copper Nanoparticles at the Soil-Root Interface  

NLE Websites -- All DOE Office Websites (Extended Search)

Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Print Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Print The first commercial fungicide-the "Bordeaux mixture" of copper sulfate and lime-was used to fight downy mildew in French vineyards. The fungicide worked by catalyzing the production of free radicals that damage proteins and enzymes involved in cycling copper between Cu(I) and Cu(II) oxidation states in the cellular electron transport chain. However, not all fungi are sensitive to copper toxicity. Some, called mycorrhizae, which live underground in symbiosis with host plants through intracellular or extracellular colonization of their roots, are resistant, although it is not known why. A team from the CNRS and Université Joseph Fourier in Grenoble in collaboration with researchers at the University of Illinois at Chicago and in partnership with the French company Phytorestore has discovered a new form of copper-metallic nanoparticles-in the rhizosphere (soil-root interface) that may explain how mycorrhizal (symbiotic) fungi detoxify copper.

5

Formation of Metallic Copper Nanoparticles at the Soil-Root Interface  

NLE Websites -- All DOE Office Websites (Extended Search)

Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Print Formation of Metallic Copper Nanoparticles at the Soil-Root Interface Print The first commercial fungicide-the "Bordeaux mixture" of copper sulfate and lime-was used to fight downy mildew in French vineyards. The fungicide worked by catalyzing the production of free radicals that damage proteins and enzymes involved in cycling copper between Cu(I) and Cu(II) oxidation states in the cellular electron transport chain. However, not all fungi are sensitive to copper toxicity. Some, called mycorrhizae, which live underground in symbiosis with host plants through intracellular or extracellular colonization of their roots, are resistant, although it is not known why. A team from the CNRS and Université Joseph Fourier in Grenoble in collaboration with researchers at the University of Illinois at Chicago and in partnership with the French company Phytorestore has discovered a new form of copper-metallic nanoparticles-in the rhizosphere (soil-root interface) that may explain how mycorrhizal (symbiotic) fungi detoxify copper.

6

Divalent metal nanoparticles  

E-Print Network (OSTI)

Metal nanoparticles hold promise for many scientific and technological applications, such as chemical and biological sensors, vehicles for drug delivery, and subdiffraction limit waveguides. To fabricate such devices, a ...

DeVries, Gretchen Anne

2008-01-01T23:59:59.000Z

7

Aerosol Route Synthesis of Copper Oxide Nanoparticles Using ...  

Science Conference Proceedings (OSTI)

Presentation Title, Aerosol Route Synthesis of Copper Oxide Nanoparticles Using Copper Nitrate Solution ... Phase Transformation Hardening by Using High -Power Direct Diode Laser ... Defect Energetics and Fission Product Transport in ZrC.

8

Evaluation of monolayer protected metal nanoparticle technology  

E-Print Network (OSTI)

Self assembling nanostructured nanoparticles represent a new class of synthesized materials with unique functionality. Such monolayer protected metal nanoparticles are capable of resisting protein adsorption, and if utilized ...

Wu, Diana J

2005-01-01T23:59:59.000Z

9

Gold-Copper Nanoparticles: Nanostructural Evolution and Bifunctional Catalytic Sites  

Science Conference Proceedings (OSTI)

Understanding of the atomic-scale structure is essential for exploiting the unique catalytic properties of any nanoalloy catalyst. This report describes novel findings of an investigation of the nanoscale alloying of gold-copper (AuCu) nanoparticles and its impact on the surface catalytic functions. Two pathways have been explored for the formation of AuCu nanoparticles of different compositons, including wet chemical synthesis from mixed Au- and Cu-precursor molecules, and nanoscale alloying via an evolution of mixed Au- and Cu-precursor nanoparticles near the nanoscale melting temperatures. For the evolution of mixed precursor nanoparticles, synchrotron x-ray based in-situ real time XRD was used to monitor the structural changes, revealing nanoscale alloying and reshaping towards an fcc-type nanoalloy (particle or cube) via a partial meltingresolidification mechanism. The nanoalloys supported on carbon or silica were characterized by in-situ high-energy XRD/PDFs, revealing an intriguing lattice "expanding-shrinking" phenomenon depending on whether the catalyst is thermochemically processed under oxidative or reductive atmosphere. This type of controllable structural changes is found to play an important role in determining the catalytic activity of the catalysts for carbon monoxide oxidation reaction. The tunable catalytic activities of the nanoalloys under thermochemically oxidative and reductive atmospheres are also discussed in terms of the bifunctional sites and the surface oxygenated metal species for carbon monoxide and oxygen activation.

Yin, Jun; Shan, Shiyao; Yang, Lefu; Mott, Derrick; Malis, Oana; Petkov, Valeri; Cai, Fan; Ng, Mei; Luo, Jin; Chen, Bing H.; Engelhard, Mark H.; Zhong, Chuan-Jian

2012-12-12T23:59:59.000Z

10

Inert electrode containing metal oxides, copper and noble metal  

DOE Patents (OSTI)

A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA); Dawless, Robert K. (Monroeville, PA); Hosler, Robert B. (Sarver, PA)

2000-01-01T23:59:59.000Z

11

Inert electrode containing metal oxides, copper and noble metal  

DOE Patents (OSTI)

A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA); Dawless, Robert K. (Monroeville, PA); Hosler, Robert B. (Sarver, PA)

2001-01-01T23:59:59.000Z

12

Metal nanoparticle inks  

DOE Patents (OSTI)

Stabilized silver particles comprise particles comprising silver, a short-chain capping agent adsorbed on the particles, and a long-chain capping agent adsorbed on the particles. The short-chain capping agent is a first anionic polyelectrolyte having a molecular weight (Mw) of at most 10,000, and the long-chain capping agent is a second anionic polyelectrolyte having a molecular weight (Mw) of at least 25,000. The stabilized silver particles have a solid loading of metallic silver of at least 50 wt %.

Lewis, Jennifer A. (Urbana, IL); Ahn, Bok Yeop (Champaign, IL); Duoss, Eric B. (Urbana, IL)

2011-04-12T23:59:59.000Z

13

Mercury Removal from Aqueous Systems Using Commercial and Laboratory Prepared Metal Oxide Nanoparticles  

E-Print Network (OSTI)

Five commercial metal oxide nanoparticles (CuO, SiO2, Fe2O3, TiO2 and Al2O3) have been individually screened for mercury removal in a batch reactor under bicarbonate buffered and non-buffered aqueous solutions (DI water). Copper oxide was then selected for surface modification to enhance mercury removal. The surfaces of both laboratory prepared and commercially available copper oxide nanoparticles were treated with 1-octanethiol to produce copper sulfide and/or copper alkanethiol nanoparticles. The resulting particles were characterized using X-Ray Fluorescence(XRF), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The novel nanoparticles demonstrated very high mercury removal (> 99%) from both the buffered and non-buffered aqueous solutions.

Desai, Ishan

2009-08-01T23:59:59.000Z

14

Modification of surface properties of copper-refractory metal alloys  

DOE Patents (OSTI)

The surface properties of copper-refractory metal (CU-RF) alloy bodies are modified by heat treatments which cause the refractory metal to form a coating on the exterior surfaces of the alloy body. The alloys have a copper matrix with particles or dendrites of the refractory metal dispersed therein, which may be niobium, vanadium, tantalum, chromium, molybdenum, or tungsten. The surface properties of the bodies are changed from those of copper to that of the refractory metal.

Verhoeven, J.D.; Gibson, E.D.

1993-10-12T23:59:59.000Z

15

Production of copper and brass nanoparticles upon laser ablation in liquids  

SciTech Connect

The production of nanoparticles upon ablation of copper and brass by pulsed radiation from Nd:YAG and copper lasers in water, ethanol, and acetone is studied. The nanoparticles were investigated by the methods of X-ray diffractometry, optical spectroscopy, and transmission electron microscopy. The produced copper and brass nanoparticles were shown to exhibit a plasmon resonance lying in the visible spectral range near 580 and 510 nm. The brass nanoparticles produced by ablation in ethanol have a shell approximately 10-nm thick for an average dimension of 20-30 nm. A chemical modification of ethanol was observed, which manifested itself in the appearance of intense UV absorption bands. Upon laser irradiation of brass nanoparticles in a liquid their absorption spectrum gradually transformed into the spectrum of copper nanoparticles. (interaction of laser radiation with matter)

Kazakevich, Pavel V; Simakin, Aleksandr V; Shafeev, Georgii A [Scientific Center for Wave Studies, A.M.Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Voronov, Valerii V [Laser Materials and Technology Research Center, A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2004-10-31T23:59:59.000Z

16

Metal Oxide Semiconductor Nanoparticles Open the Door to ...  

Using metal oxide semiconductor nanoparticles to target and control biological molecules could fuel medical breakthroughs in many areas, including ...

17

Method for extracting copper, silver and related metals  

DOE Patents (OSTI)

A process for selectively extracting precious metals such as silver and gold concurrent with copper extraction from aqueous solutions containing the same. The process utilizes tetrathiamacrocycles and high molecular weight organic acids that exhibit a synergistic relationship when complexing with certain metal ions thereby removing them from ore leach solutions.

Moyer, B.A.; McDowell, W.J.

1987-10-23T23:59:59.000Z

18

Copper and Zinc Metallation Status of Copper Zinc Superoxide Dismutase form Amyotrophic Lateral Sclerosis Transgenic Mice  

Science Conference Proceedings (OSTI)

Mutations in the metalloenzyme copper-zinc superoxide dismutase (SOD1) cause one form of familial amyotrophic lateral sclerosis (ALS), and metals are suspected to play a pivotal role in ALS pathology. To learn more about metals in ALS, we determined the metallation states of human wild-type or mutant (G37R, G93A, and H46R/H48Q) SOD1 proteins from SOD1-ALS transgenic mice spinal cords. SOD1 was gently extracted from spinal cord and separated into insoluble (aggregated) and soluble (supernatant) fractions, and then metallation states were determined by HPLC inductively coupled plasma MS. Insoluble SOD1-rich fractions were not enriched in copper and zinc. However, the soluble mutant and WT SOD1s were highly metallated except for the metal-binding-region mutant H46R/H48Q, which did not bind any copper. Due to the stability conferred by high metallation of G37R and G93A, it is unlikely that these soluble SOD1s are prone to aggregation in vivo, supporting the hypothesis that immature nascent SOD1 is the substrate for aggregation. We also investigated the effect of SOD1 overexpression and disease on metal homeostasis in spinal cord cross-sections of SOD1-ALS mice using synchrotron-based x-ray fluorescence microscopy. In each mouse genotype, except for the H46R/H48Q mouse, we found a redistribution of copper between gray and white matters correlated to areas of high SOD1. Interestingly, a disease-specific increase of zinc was observed in the white matter for all mutant SOD1 mice. Together these data provide a picture of copper and zinc in the cell as well as highlight the importance of these metals in understanding SOD1-ALS pathology.

Lelie, H.L.; Miller, L.; Liba, A.; Bourassa, M.W.; Chattopadhyay, M.; Chan, P.K.; Gralla, E.B.; Borchelt, D.R.; et al

2010-09-24T23:59:59.000Z

19

Metal Oxide Semiconductor Nanoparticles Pave the Way for ...  

Argonne researchers have developed a unique application of technology that involves using metal oxide semiconductor nanoparticles to target and control biological ...

20

New thiophene monolayer-protected copper nanoparticles: synthesis and chemical-physical characterization  

Science Conference Proceedings (OSTI)

For the first time copper 3-(6-mercaptohexyl) thiophene-protected nanoparticles (Cu T6SH) have been synthesized by a one-phase system, utilizing an NaBH4/LiCl mixture in diglyme as the reducing reagent and avoiding water medium dissolving ...

Elisabetta Foresti; Guido Fracasso; Massimiliano Lanzi; Isidoro Giorgio Lesci; Luisa Paganin; Tommaso Zuccheri; Norberto Roveri

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "metallic copper nanoparticles" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Stabilization of Electrocatalytic Metal Nanoparticles at Metal-Metal Oxide-Graphene Triple Junction Points  

DOE Green Energy (OSTI)

Carbon-supported metal catalysts are widely used in heterogeneous catalysis and electrocatalysis. In this paper, we report a novel method to deposit metal catalysts and metal oxide nanoparticles on two-dimensional graphene sheets to improve the catalytic performance and stability of the catalyst materials. The new synthesis method allows indium tin oxide (ITO) nanocrystals to be directly grown on functionalized graphene sheets forming the ITO-graphene hybrids. Pt nanoparticles are then deposited to form a special triple-junction structure (Pt-ITO-graphene). Both experimental study and periodic density functional theory calculations show that the supported Pt nanoparticles are stable at Pt-ITO-graphene triple junction points. The new catalyst materials were tested for oxygen reduction for potential applications in polymer electrolyte membrane fuel cells, and they exhibited greatly enhanced stability and activity. The reasons for the high stability and activity of Pt-ITO-graphene are analyzed.

Kou, Rong; Shao, Yuyan; Mei, Donghai; Nie, Zimin; Wang, Donghai; Wang, Chong M.; Viswanathan, Vilayanur V.; Park, Seh K.; Aksay, Ilhan A.; Lin, Yuehe; Wang, Yong; Liu, Jun

2011-03-02T23:59:59.000Z

22

Dendrimer-encapsulated metal nanoparticles: synthesis, characterization, and applications to catalysis  

E-Print Network (OSTI)

The research in this dissertation examines the chemistry and applications of dendrimers in homogeneous catalysis. We examined interactions between dendrimers and charged probe molecules, prepared dendrimer-encapsulated metal nanoparticles in organic solvents, studied size-selectivity of dendrimer-encapsulted catalysts, and designed molecular rulers as in-situ probes to measure the location of dendrimer-encapsulted metal nanoparticles. The intrinsic proton binding constant and a constant that characterizes the strength of electrostatic interactions among occupied binding sites in poly(amidoamine) (PAMAM) dendrimers have been obtained by studying the effect of solution pH on the protonation of the dendrimers. The significant finding is that these two factors are greatly modulated by the unique and hydrophobic microenvironment in the dendrimer interior. Hydrophilic poly(propylene imine) (PPI) dendrimers were modified with various hydrophobic alkyl chains through an amide linkage and were then used as templates for preparing intradendrimer copper nanoclusters. The main driving force for encapsulating metal-ions was found to be the differences in metal-ion solubility between the solvent and the interior of the dendrimer. Nanometer-sized metal particles are synthesized and encapsulated into the interior of dendrimers by first mixing together the dendrimer and metal ion solution and then reducing the composite chemically, and the resulting dendrimer-encapsulated metal nanoparticles can then be used as catalysts. By controlling the packing density on the dendrimer periphery using either different dendrimer generations or dendrimer surface functionalities, it is possible to control access of substrates to the encapsulated catalytic nanoparticle. Molecular rulers consisting of a large molecular "stopper", a reactive probe and a linker were designed as in-situ probes for determining the average distance between the surface of dendrimer-encapsulated palladium nanoparticles and the periphery of their fourth-generation, hydroxyl-terminated PAMAM dendrimer hosts. By doing so, we avoid having to make assumptions about the nanoparticle size and shape. The results suggest that the surface of the encapsulated nanoparticle is situated 0.7 0.2 nm from the surface of the dendrimer.

Niu, Yanhui

2003-05-01T23:59:59.000Z

23

Metallic Nanocomposites Powders Fabricated through Nanoparticle ...  

Science Conference Proceedings (OSTI)

Ultrasonic processing technique was utilized to distribute and disperse TiCN nanoparticles and Al droplets in the molten salt of eutectic NaCl/KCl.

24

Uniform Dispersion of Nanoparticles in Metal Matrix Nanocomposites  

Science Conference Proceedings (OSTI)

Conference Tools for 2012 TMS Annual Meeting & Exhibition ... Two examples are presented in this report: (1) uniform dispersion of Al2O3 nanoparticles in A206 ... Aluminum Metal Matrix Composite via Direct Metal Laser Deposition: Processing And Mechanical Characterization ... Contact programming@

25

Precipitation of heterogeneous nanostructures: Metal nanoparticles and dielectric nanocrystallites  

Science Conference Proceedings (OSTI)

Heterogeneous precipitation of nanocrystallites of metallic Bi and anatase was observed in CaO-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-TiO{sub 2} glass-ceramics. Addition of AlN reduced the Bi{sub 2}O{sub 3} to Bi metal nanoparticles, which were uniformly dispersed in the glass. After heat-treatment of the Bi-precipitated glass around the glass transition temperature, nanocrystalline anatase precipitated out without aggregation of the Bi metal particles. It was found that the anatase nanocrystal size was affected by the distance between a nanocrystal and a precipitated Bi nanoparticle. The glass-ceramic produced is a functional material containing a random dispersion of different types of nanoparticles with different dielectric constants.

Masai, Hirokazu; Takahashi, Yoshihiro; Fujiwara, Takumi [Department of Applied Physics, Tohoku University, 6-6-05, Aoba, Aoba-ku, Sendai 980-8579 (Japan); Tokuda, Yomei; Yoko, Toshinobu [Institute for Chemical Research, Kyoto University, Gokasyo, Uji, Kyoto 611-0011 (Japan)

2010-07-15T23:59:59.000Z

26

Selective Electrocatalytic Activity of Ligand Stabilized Copper Oxide Nanoparticles  

DOE Green Energy (OSTI)

Ligand stabilization can influence the surface chemistry of Cu oxide nanoparticles (NPs) and provide unique product distributions for electrocatalytic methanol (MeOH) oxidation and CO{sub 2} reduction reactions. Oleic acid (OA) stabilized Cu{sub 2}O and CuO NPs promote the MeOH oxidation reaction with 88% and 99.97% selective HCOH formation, respectively. Alternatively, CO{sub 2} is the only reaction product detected for bulk Cu oxides and Cu oxide NPs with no ligands or weakly interacting ligands. We also demonstrate that OA stabilized Cu oxide NPs can reduce CO{sub 2} into CO with a {approx}1.7-fold increase in CO/H{sub 2} production ratios compared to bulk Cu oxides. The OA stabilized Cu oxide NPs also show 7.6 and 9.1-fold increases in CO/H{sub 2} production ratios compared to weakly stabilized and non-stabilized Cu oxide NPs, respectively. Our data illustrates that the presence and type of surface ligand can substantially influence the catalytic product selectivity of Cu oxide NPs.

Kauffman, Douglas R.; Ohodnicki, Paul R.; Kail, Brian W; Matranga, Christopher

2011-01-01T23:59:59.000Z

27

Oxhide ingots, copper production, and the mediterranean trade in copper and other metals in the bronze age  

E-Print Network (OSTI)

The production and trade in copper and bronze was one of the major features of the complex societies in the Near East and Mediterranean during the third to first millennia B.C. While finished metal objects are common finds from the period, ancient metal ingots and hoards of scrap metal, as well as archaeological evidence of metallurgical activities, are often more important sources of information for how ancient technology and trade functioned. Shipwrecks, particularly those found off the coast of Turkey at Uluburun and Cape Gelidonya, as well as mining and smelting sites in the Mediterranean region, provide invaluable information on the production and trade of copper and tin, the main ingredients of bronze. In this thesis, I examine the evolution of the copper trade in the eastern and central Mediterranean, particularly during the Late Bronze Age, when â??oxhideâ?? ingots were widely exported. Finds of oxhide ingots have increased dramatically in recent years, and no synthesis of all of this newly available evidence is currently available. I attempt to analyze this new evidence in relation to older finds and research, with a particular focus on the cargo of the Uluburun shipwreck, the largest collection of Bronze Age metal ingots from a single site in the Mediterranean. The history of oxhide ingot production is complex, but by the Late Bronze Age Cyprus was supplying much of the copper used to neighboring regions, with revolutionary effects on societies in Cyprus and elsewhere. The archaeological evidence shows that oxhide ingots are early examples of a standardized industrial product made for export by emerging state-level societies during the second millennium B.C. and fueled the development of international trade, metallurgical technology, and complex social institutions in a variety of Mediterranean societies from Egypt and the Levant, Greece, Cyprus, to Sardinia in the central Mediterranean.

Jones, Michael Rice

2003-05-01T23:59:59.000Z

28

Copper-silver-titanium filler metal for direct brazing of structural ceramics  

DOE Patents (OSTI)

A method of joining ceramics and metals to themselves and to one another is described using a brazing filler metal consisting essentially of 35 to 50 atomic percent copper, 15 to 50 atomic percent silver and 10 to 45 atomic percent titanium. This method produces strong joints that can withstand high service temperatures and oxidizing environments.

Moorhead, Arthur J. (Knoxville, TN)

1987-01-01T23:59:59.000Z

29

Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst  

SciTech Connect

Carbon monoxide oxidation was performed over the three different oxidation states of copper -- metallic (Cu), copper (I) oxide (Cu{sub 2}O), and copper (II) oxide (CuO) as a test case for developing a model metal oxide catalyst amenable to study by the methods of modern surface science and catalysis. Copper was deposited and oxidized on oxidized supports of aluminum, silicon, molybdenum, tantalum, stainless steel, and iron as well as on graphite. The catalytic activity was found to decrease with increasing oxidation state (Cu > Cu{sub 2}O > CuO) and the activation energy increased with increasing oxidation state (Cu, 9 kcal/mol < Cu{sub 2}O, 14 kcal/mol < CuO, 17 kcal/mol). Reaction mechanisms were determined for the different oxidation states. Lastly, NO reduction by CO was studied. A Cu and CuO catalyst were exposed to an equal mixture of CO and NO at 300--350 C to observe the production of N{sub 2} and CO{sub 2}. At the end of each reaction, the catalyst was found to be Cu{sub 2}O. There is a need to study the kinetics of this reaction over the different oxidation states of copper.

Jernigan, G.G. [California Univ., Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States). Materials and Chemical Sciences Div.

1994-10-01T23:59:59.000Z

30

Solution synthesis of mixed-metal chalcogenide nanoparticles and spray deposition of precursor films  

DOE Patents (OSTI)

A colloidal suspension comprising metal chalcogenide nanoparticles and a volatile capping agent. The colloidal suspension is made by reacting a metal salt with a chalcogenide salt in an organic solvent to precipitate a metal chalcogenide, recovering the metal chalcogenide, and admixing the metal chalcogenide with a volatile capping agent. The colloidal suspension is spray deposited onto a substrate to produce a semiconductor precursor film which is substantially free of impurities.

Schulz, Douglas L. (Denver, CO); Curtis, Calvin J. (Lakewood, CO); Ginley, David S. (Evergreen, CO)

2000-01-01T23:59:59.000Z

31

High-Efficiency 6?? Multicrystalline Black Solar Cells Based on Metal-Nanoparticle-Assisted Chemical Etching  

E-Print Network (OSTI)

Multicrystalline silicon (mc-Si) photovoltaic (PV) solar cells with nanoscale surface texturing by metal-nanoparticle-assisted etching are proposed to achieve high power efficiency. The investigation of average nanorod ...

Hsu, W. Chuck

2012-01-01T23:59:59.000Z

32

Computational Studies of Graphene-Supported Metal Nanoparticle ...  

Science Conference Proceedings (OSTI)

... Active Titania-Based Nanoparticles for Composite Propellant Combustion ... of Novel Nanostructured Electrolytes for Low Temperature Solid Oxide Fuel Cells...

33

Formation of metal nanoparticles by short-distance sputter deposition in a reactive ion etching chamber  

Science Conference Proceedings (OSTI)

A new method is reported to form metal nanoparticles by sputter deposition inside a reactive ion etching chamber with a very short target-substrate distance. The distribution and morphology of nanoparticles are found to be affected by the distance, the ion concentration, and the sputtering time. Densely distributed nanoparticles of various compositions were fabricated on the substrates that were kept at a distance of 130 mum or smaller from the target. When the distance was increased to 510 mum, island structures were formed, indicating the tendency to form continuous thin film with longer distance. The observed trend for nanoparticle formation is opposite to the previously reported mechanism for the formation of nanoparticles by sputtering. A new mechanism based on the seeding effect of the substrate is proposed to interpret the experimental results.

Nie Min; Meng, Dennis Desheng [Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, Michigan 49931 (United States); Sun Kai [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2009-09-01T23:59:59.000Z

34

Dispersion strengthened copper  

DOE Patents (OSTI)

A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.

Sheinberg, H.; Meek, T.T.; Blake, R.D.

1990-01-09T23:59:59.000Z

35

Laser interactions with embedded Ca metal nanoparticles in single crystal CaF{sub 2}  

SciTech Connect

Single crystal calcium fluoride (CaF{sub 2}) is an important material for vacuum-ultraviolet optics. Nevertheless, prolonged exposure to energetic radiation can color the material by producing calcium metal nanoparticles. We compare the effectiveness of laser conditioning treatments at wavelengths ranging from the near infrared to the deep ultraviolet in removing this coloration. Treatments at 157, 532, and 1064 nm can significantly reduce the visible coloration due to nanoparticles. In contrast, irradiation at 248 nm has little effect at fluences below the damage threshold for the material employed in this work. We present evidence that the effect of laser irradiation on coloration is principally thermal and is largely confined to the first 50 ns after each laser pulse. We attribute the wavelength dependence of the bleaching process to the wavelength dependence associated with Mie absorption by metal nanoparticles. The consequences of these observations with regard to laser conditioning processes in bulk optical materials are discussed.

Cramer, L.P.; Schubert, B.E.; Petite, P.S.; Langford, S.C.; Dickinson, J.T. [Materials Science Program and Physics Department, Washington State University, Pullman, Washington 99164-2814 (United States)

2005-04-01T23:59:59.000Z

36

Electrical and gas sensing properties of self-aligned copper-doped zinc oxide nanoparticles  

Science Conference Proceedings (OSTI)

Electrical and gas sensing properties of nanocrystalline ZnO:Cu, having Cu X wt% (X = 0.0, 0.5, 1.0, and 1.5) in ZnO, in the form of pellet were investigated. Copper chloride and zinc acetate were used as precursors along with oxalic acid as a precipitating reagent in methanol. Material characterization was done by X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM) and inductive coupled plasma with optical emission spectrometry (ICP-OES). FE-SEM showed the self-aligned Cu-doped ZnO nano-clusters with particles in the range of 40-45 nm. The doping of 0.5% of copper changes the electrical conductivity by an order of magnitude whereas the temperature coefficient of resistance (TCR) reduces with increase in copper wt% in ZnO. The material has shown an excellent sensitivity for the H{sub 2}, LPG and CO gases with limited temperature selectivity through the optimized operating temperature of 130, 190 and 220 deg. C for H{sub 2}, LPG and CO gases, respectively at 625 ppm gas concentration. The %SF was observed to be 1460 for H{sub 2} at 1% Cu doping whereas the 0.5% Cu doping offered %SF of 950 and 520 for CO and LPG, respectively. The response and recovery time was found to be 6 to 8 s and 16 s, respectively.

Sonawane, Yogesh S. [Thin Film Laboratory, Department of Physics, University of Pune, Pune 411007 (India); Kanade, K.G. [Department of Chemistry, Mahatma Phule College, Pimpari, Pune 411017 (India); Kale, B.B. [Nanocrystalline Materials Laboratory, Center for Materials for Electronics Technology (CMET), Pune 411008 (India)], E-mail: kbbb1@yahoo.co.in; Aiyer, R.C. [Center for Sensor Studies, Department of Physics, University of Pune, Pune 411007 (India)], E-mail: rca@physics.unipune.ernet.in

2008-10-02T23:59:59.000Z

37

NiO as a peculiar support for metal nanoparticles in polyols oxidation  

SciTech Connect

The peculiar influence of a NiO support was studied by preparing gold catalysts supported on NiO(1-x) TiO2(x) mixed oxides. PVA protected Au nanoparticles showed high activity when supported on NiO for the selective oxidation of glycerol and ethan-1,2-diol. A detailed characterization of the resulting Au catalysts revealed a preferential deposition of the metal nanoparticles on the NiO phase. However, the activity of Au on NiO(1-x)-TiO2(x) decreased with respect to pure NiO and the selectivity evolved with changes to the support.

Villa, Alberto [Universita di Milano, Italy; Veith, Gabriel M [ORNL; Ferri, Davide [EMPA, Laboratory for High Performance Ceramics, Duebendorf, Switzerland; Weidenkaff, Anke [EMPA, Laboratory for High Performance Ceramics, Duebendorf, Switzerland; Perry, Kelly A [ORNL; Campisi, Sebastiano [University of Milan and INFN, Milano, Italy; Prati, Laura [Universita di Milano, Italy

2013-01-01T23:59:59.000Z

38

Microfluidic Synthesis of Nickel Nanoparticles  

Science Conference Proceedings (OSTI)

In the current investigation, we aim at synthesizing nickel nanoparticles of ... A Novel Type of Carbon Coated Sulfur Nanoparticles for Li/S Batteries .... Production and Mechanical Properties of Nanostructured Copper and Copper Zinc Alloys.

39

Final Report: Sintered CZTS Nanoparticle Solar Cells on Metal Foil; July 26, 2011 - July 25, 2012  

DOE Green Energy (OSTI)

This is the final report covering 12 months of this subcontract for research on high-efficiency copper zinc tin sulfide (CZTS)-based thin-film solar cells on flexible metal foil. Each of the first three quarters of the subcontract has been detailed in quarterly reports. In this final report highlights of the first three quarters will be provided and details will be given of the final quarter of the subcontract.

Leidholm, C.; Hotz, C.; Breeze, A.; Sunderland, C.; Ki, W.; Zehnder, D.

2012-09-01T23:59:59.000Z

40

Recent trends in the microwave-assisted synthesis of metal oxide nanoparticles supported on carbon nanotubes and their applications  

Science Conference Proceedings (OSTI)

The study of coating carbon nanotubes with metal/oxides nanoparticles is now becoming a promising and challenging area of research. To optimize the use of carbon nanotubes in various applications, it is necessary to attach functional groups or other ...

Sarah C. Motshekga; Sreejarani K. Pillai; Suprakas Sinha Ray; Kalala Jalama; Rui. W. M. Krause

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "metallic copper nanoparticles" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Influence of Metal Ions on the Synthesis of Silver Nanoparticles  

Science Conference Proceedings (OSTI)

Adsorption of Lead and Cadmium onto Natural and Modified Diatomite ... Mechanical Properties of 5083 Aluminium Welds after Manual and Automatic Pulsed Gas Metal Arc Welding Using ... Tool Failure Criteria while Drilling Titanium Alloys.

42

Systematic Approach to Compare the Inflammatory Response of Liver Cell Culture Systems Exposed to Silver, Copper, and Nickel Nanoparticles  

E-Print Network (OSTI)

Although nano-sized metal colloids are used in industrial and medicinal applications, little is known about the potential liver toxicity of these materials after occupational or intentional exposures. To begin to resolve some outstanding hepatotoxicity concerns, the inflammatory response of hepatocytes after exposure to metal colloids was assessed. Four ~30-nm-sized metal colloids, including silver (nano-Ag), copper (nano-Cu) and nickel (nano-Ni) were examined in an effort to understand the induced cytokine expression in a murine liver cell line (AML12). Here we also utilized another system, co-cultures of hepatocytes, Kupffers cells, and lymphocytes isolated from C57BL6 mice. Cells were exposed to the materials over dose-response (0.1mg/L to 1000mg/L) and time-dependent (4 h, 48 h, and 1-week) studies. Cytotoxicity was measured via metabolism of resazurin and validated via MTT assay and cell counts. Inflammatory response was determined by cytokine profiles (TNF-a and IL-6), as well as by mRNA and protein expression of heat shock protein (Hsp70). Results from cells exposed to nano-Ag to doses of up to 100mg/L exhibited no significant changes in cytotoxicity, IL-6, or TNF-a production, or Hsp70 expression. Both nano-Cu and nano-Ni exposed cells exhibited decreased metabolism, increased Hsp70 induction, and increased inflammatory responses (IL-6 and TNF-a). Dynamic light scattering and electron microscopy were used to characterize particle size and surface charge. All three metal colloidal systems demonstrated different particle size distributions, agglomerated sizes, and surface zeta potentials. Furthermore, each metal colloid system elicited different inflammatory biomarker responses and stress protein expression.

Banerjee, Nivedita

2010-08-01T23:59:59.000Z

43

Manganese Doping of Magnetic Iron Oxide Nanoparticles: Tailoring Surface Reactivity for a Regenerable Heavy Metal Sorbent  

SciTech Connect

A method for tuning the analyte affinity of magnetic, inorganic nanostructured sorbents for heavy metal contaminants is described. The manganese-doped iron oxide nanoparticle sorbents have a remarkably high affinity compared to the precursor material. Sorbent affinity can be tuned toward an analyte of interest simply by adjustment of the dopant quantity. The results show that following the Mn doping process there is a large increase in affinity and capacity for heavy metals (i.e., Co, Ni, Zn, As, Ag, Cd, Hg, and Tl). Capacity measurements were carried out for the removal of cadmium from river water and showed significantly higher loading than the relevant commercial sorbents tested for comparison. The reduction in Cd concentration from 100 ppb spiked river water to 1 ppb (less than the EPA drinking water limit of 5 ppb for Cd) was achieved following treatment with the Mn-doped iron oxide nanoparticles. The Mn-doped iron oxide nanoparticles were able to load 1 ppm of Cd followed by complete stripping and recovery of the Cd with a mild acid wash. The Cd loading and stripping is shown to be consistent through multiple cycles with no loss of sorbent performance.

Warner, Cynthia L.; Chouyyok, Wilaiwan; Mackie, Katherine E.; Neiner, Doinita; Saraf, Laxmikant; Droubay, Timothy C.; Warner, Marvin G.; Addleman, Raymond S.

2012-02-28T23:59:59.000Z

44

Strengthening porous metal skeletons by metal deposition from a nanoparticle dispersion  

E-Print Network (OSTI)

The accuracy of solid freeform fabrication processes such as three-dimensional printing (3DP) and selective laser sintering (SLS) must be improved for them to achieve wide application in direct production of metal parts. ...

Crane, Nathan B., 1974-

2005-01-01T23:59:59.000Z

45

Removal of copper from ferrous scrap  

DOE Patents (OSTI)

A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

Blander, M.; Sinha, S.N.

1987-07-30T23:59:59.000Z

46

Removal of copper from ferrous scrap  

DOE Patents (OSTI)

A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

Blander, M.; Sinha, S.N.

1990-05-15T23:59:59.000Z

47

Removal of copper from ferrous scrap  

DOE Patents (OSTI)

A process for removing copper from ferrous or other metal scrap in which the scrap is contacted with a polyvalent metal sulfide slag in the presence of an excess of copper-sulfide forming additive to convert the copper to copper sulfide which is extracted into the slag to provide a ratio of copper in the slag to copper in the metal scrap of at least about 10.

Blander, Milton (12833 S. 82nd Ct., Palos Park, IL 60464); Sinha, Shome N. (5748 Drexel, 2A, Chicago, IL 60637)

1990-01-01T23:59:59.000Z

48

Near-field enhancement of metal nano-particle based on the light focusing by the micro-parabolic mirror  

E-Print Network (OSTI)

Near-field enhancement of metal nano-particle based on the light focusing by the micro-parabolic mirror , , , , Abstract We propose to use a micro-parabolic mirror, in order to improve the near- parabolic mirror, the mirror-reflected light can be efficiently transformed into the near-field of the nano

Park, Namkyoo

49

Investigation of the ligand shells of homo-ligand and mixed-ligand monolayer protected metal nanoparticles : a scanning tunneling microscopy study  

E-Print Network (OSTI)

Monolayer Protected Metal Nanoparticles have recently found widespread use in and are the focus of intensive study in many areas of scientific research ranging from biology to physics to medicine. Consisting of a nanoscale, ...

Jackson, Alicia M

2007-01-01T23:59:59.000Z

50

Nanoparticles  

NLE Websites -- All DOE Office Websites (Extended Search)

Benjamin Gilbert1, Feng Huang1, Hengzhong Zhang1, Glenn A. Waychunas2, and Benjamin Gilbert1, Feng Huang1, Hengzhong Zhang1, Glenn A. Waychunas2, and Jillian F. Banfield1,2 1Department of Earth and Planetary Sciences, University of California at Berkeley 2Earth Sciences Division, Lawrence Berkeley National Laboratory Using synchrotron techniques, Benjamin Gilbert and colleagues in Jill Banfield's group at the University of California - Berkeley and Glenn Waychunas at LBNL have determined how the equilibrium structure and lattice dynamics of zinc sulfide (ZnS) nanoparticles differ from bulk ZnS. They combined size and shape information from small-angle x-ray scattering (SAXS) with structure information from wide-angle x-ray scattering (WAXS) to analyze structural differences in the real-space pair distribution function (PDF). By combining SAXS and WAXS, they were able to remove the small-particle size contribution to x-ray diffraction peak broadening and quantify the excess disorder and strain in the nanoparticles relative to bulk ZnS.

51

The formation of metallic nanoparticles in single crystal CaF{sub 2} under 157 nm excimer laser irradiation  

SciTech Connect

Single crystal calcium fluoride (CaF{sub 2}) is an important material for vacuum-ultraviolet optical components. Unfortunately, all metal halides tend to form defects when exposed to energetic particles and laser radiation, and these defects can degrade optical performance. Here we examine the consequences of exposing CaF{sub 2} to 157 nm excimer laser radiation and show that several tens of thousands of pulses at fluences near 1 J/cm{sup 2} can color the material. Absorption spectra of the exposed material confirm the formation of metallic calcium nanoparticles similar to those produced by other forms of energetic radiation. The rate of nanoparticle formation depends on the bulk temperature and displays a local maximum near 50 deg. C. Absorption measurements at 157 nm display a transient absorption component that grows during prolonged irradiation and disappears on time scales of several minutes after irradiation ceases. The implications of these effects in optical components are discussed.

Cramer, L.P.; Langford, S.C.; Dickinson, J.T. [Physics Department, Washington State University, Pullman, Washington 99164-2814 (United States)

2006-03-01T23:59:59.000Z

52

Nanoparticles as Reactive Precursors: Synthesis of Alloys, Intermetallic Compounds, and Multi-Metal Oxides Through Low-Temperature Annealing and Conversion Chemistry  

E-Print Network (OSTI)

Alloys, intermetallic compounds and multi-metal oxides are generally made by traditional solid-state methods that often require melting or grinding/pressing powders followed by high temperature annealing (> 1000 degrees C) for days or weeks. The research presented here takes advantage of the fact that nanoparticles have a large fraction of their atoms on the surface making them highly reactive and their small size virtually eliminates the solid-solid diffusion process as the rate limiting step. Materials that normally require high temperatures and long annealing times become more accessible at relatively low-temperatures because of the increased interfacial contact between the nanoparticle reactants. Metal nanoparticles, formed via reduction of metal salts in an aqueous solution and stabilized by PVP (polyvinylpyrrolidone), were mixed into nanoparticle composites in stoichometric proportions. The composite mixtures were then annealed at relatively low temperatures to form alloy and intermetallic compounds at or below 600 degrees C. This method was further extended to synthesizing multi-metal oxide systems by annealing metal oxide nanoparticle composites hundreds of degrees lower than more traditional methods. Nanoparticles of Pt (supported or unsupported) were added to a metal salt solution of tetraethylene glycol and heated to obtain alloy and intermetallic nanoparticles. The supported intermetallic nanoparticles were tested as catalysts and PtPb/Vulcan XC-72 showed enhanced catalytic activity for formic acid oxidation while Pt3Sn/Vulcan XC-72 and Cu3Pt/y-Al2O3 catalyzed CO oxidiation at lower temperatures than supported Pt. Intermetallic nanoparticles of Pd were synthesized by conversion chemistry methods previously mentioned and were supported on carbon and alumina. These nanoparticles were tested for Suzuki cross-coupling reactions. However; the homocoupled product was generally favored. The catalytic activity of Pd3Pb/y-Al2O3 was tested for the Heck reaction and gave results comparable to Pd/y-Al2O3 with a slightly better selectivity. Conversion chemistry techniques were used to convert Pt nanocubes into Ptbased intermetallic nanocrystals in solution. It was discovered that aggregated clusters of Pt nanoparticles were capable of converting to FePt3; however, when Pt nanocubes were used the intermetallic phase did not form. Alternatively, it was possible to form PtSn nanocubes by a conversion reaction with SnCl2.

Bauer, John C.

2009-05-01T23:59:59.000Z

53

Low Temperature Bonding Process Using Cu Nanoparticles  

Science Conference Proceedings (OSTI)

Aerosol Route Synthesis of Copper Oxide Nanoparticles Using Copper Nitrate Solution AlGaAs-Based Optical ... Defect Energetics and Fission Product Transport in ZrC ... Enhancing Mineral Beneficiation by High Intensity Power Ultrasound.

54

Plasma stabilisation of metallic nanoparticles on silicon for the growth of carbon nanotubes  

SciTech Connect

Ammonia (NH{sub 3}) plasma pretreatment is used to form and temporarily reduce the mobility of Ni, Co, or Fe nanoparticles on boron-doped mono- and poly-crystalline silicon. X-ray photoemission spectroscopy proves that NH{sub 3} plasma nitrides the Si supports during nanoparticle formation which prevents excessive nanoparticle sintering/diffusion into the bulk of Si during carbon nanotube growth by chemical vapour deposition. The nitridation of Si thus leads to nanotube vertical alignment and the growth of nanotube forests by root growth mechanism.

Esconjauregui, S.; Fouquet, M.; Bayer, B. C.; Gamalski, A. D.; Chen Bingan; Xie Rongsi; Hofmann, S.; Robertson, J. [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Cepek, C.; Bhardwaj, S. [Istituto Officina dei Materiali-CNR, Laboratorio TASC, s.s. 14 km 163.5, I-34149 Trieste (Italy); Ducati, C. [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom)

2012-08-01T23:59:59.000Z

55

De-alloyed platinum nanoparticles  

DOE Patents (OSTI)

A method of producing de-alloyed nanoparticles. In an embodiment, the method comprises admixing metal precursors, freeze-drying, annealing, and de-alloying the nanoparticles in situ. Further, in an embodiment de-alloyed nanoparticle formed by the method, wherein the nanoparticle further comprises a core-shell arrangement. The nanoparticle is suitable for electrocatalytic processes and devices.

Strasser, Peter (Houston, TX); Koh, Shirlaine (Houston, TX); Mani, Prasanna (Houston, TX); Ratndeep, Srivastava (Houston, TX)

2011-08-09T23:59:59.000Z

56

Colloid Science of Metal Nanoparticle Catalysts in 2D and 3D Structures. Challenges of Nucleation, Growth, Composition, Particle Shape, Size Control and their Influence on Activity and Selectivity  

SciTech Connect

Recent breakthroughs in synthesis in nanosciences have achieved control of size and shapes of nanoparticles that are relevant for catalyst design. In this article, we review the advance of synthesis of nanoparticles, fabrication of two and three dimensional model catalyst system, characterization, and studies of activity and selectivity. The ability to synthesize monodispersed platinum and rhodium nanoparticles in the 1-10 nm range permitted us to study the influence of composition, structure, and dynamic properties of monodispersed metal nanoparticle on chemical reactivity and selectivity. We review the importance of size and shape of nanoparticles to determine the reaction selectivity in multi-path reactions. The influence of metal-support interaction has been studied by probing the hot electron flows through the metal-oxide interface in catalytic nanodiodes. Novel designs of nanoparticle catalytic systems are discussed.

Somorjai, Gabor A.; Park, Jeong Y.

2008-02-13T23:59:59.000Z

57

Biofabrication of discrete spherical gold nanoparticles using the metal-reducing bacterium, Shewanella oneidensis  

Science Conference Proceedings (OSTI)

Nanocrystallites have garnered substantial interest due to their varying applications including catalysis. Consequently important aspects related to control of shape/size and syntheses through economical and non-hazardous means are desirable. Highly efficient bioreduction based natural fabrication approaches that utilize microbes and or -plant extracts are poised to meet these needs. Here we show that the gamma- proteobacterium, Shewanella oneidensis MR-1, can reduce tetrachloro aurate (III) ions, producing discrete extracellular spherical gold nanocrystallites. The particles were homogeneous with multiple size distributions and produced under ambient conditions at high yield, 88% of theoretical maximum. Further characterization revealed that the particles consist of spheres in the size range of 2-50 nm, with an average of 12 5 nm. The nanoparticles were hydrophilic, biocompatible, and resisted aggregation even after several months. The particles are likely capped by a detachable protein/peptide coat. UV-vis and Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray spectra and transmission electron microscopy measurements confirmed the formation as well the crystalline nature of the nanoparticles. The antibacterial activity of these gold nanoparticles was assessed using Gram-negative (E. coli and S. oneidensis) and Gram-positive (B. subtilis) bacteria. Toxicity assessments divulged that the particles were neither toxic nor inhibitory to any of these bacteria.

Suresh, Anil K [ORNL; Pelletier, Dale A [ORNL; Wang, Wei [ORNL; Broich, Michael L [ORNL; Moon, Ji Won [ORNL; Gu, Baohua [ORNL; Allison, David P [ORNL; Joy, David Charles [ORNL; Phelps, Tommy Joe [ORNL; Doktycz, Mitchel John [ORNL

2011-01-01T23:59:59.000Z

58

Metal-Semiconductor Transitions in Nanoscale Vanadium Dioxide - Thin Films, Subwavelength Holes, and Nanoparticles.  

E-Print Network (OSTI)

??Large-volume (bulk) vanadium dioxide (VO2) is an unusual material that undergoes a critical transition from insulating-like to metal-like when the temperature is raised above approximately (more)

Donev, Eugenii U.

2008-01-01T23:59:59.000Z

59

Electrospun carbon nanofiber electrodes decorated with palladium metal nanoparticles : fabrication and characterization  

E-Print Network (OSTI)

A new method was investigated to produce a novel oxygen reduction electrode comprised of carbon nanofibers for use in polymer electrolyte membrane (PEM) fuel cells and metal-air batteries. The process involved electrospinning ...

Kurpiewski, John Paul

2005-01-01T23:59:59.000Z

60

Chemical and structural investigations of the incorporation of metal manganese into ruthenium thin films for use as copper diffusion barrier layers  

Science Conference Proceedings (OSTI)

The incorporation of manganese into a 3 nm ruthenium thin-film is presented as a potential mechanism to improve its performance as a copper diffusion barrier. Manganese ({approx}1 nm) was deposited on an atomic layer deposited Ru film, and the Mn/Ru/SiO{sub 2} structure was subsequently thermally annealed. X-ray photoelectron spectroscopy studies reveal the chemical interaction of Mn with the SiO{sub 2} substrate to form manganese-silicate (MnSiO{sub 3}), implying the migration of the metal through the Ru film. Electron energy loss spectroscopy line profile measurements of the intensity of the Mn signal across the Ru film confirm the presence of Mn at the Ru/SiO{sub 2} interface.

McCoy, A. P.; Casey, P.; Bogan, J.; Hughes, G. [School of Physical Sciences, Dublin City University, Dublin 9 (Ireland); Lozano, J. G.; Nellist, P. D. [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom)

2012-12-03T23:59:59.000Z

Note: This page contains sample records for the topic "metallic copper nanoparticles" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Volatility of copper  

SciTech Connect

The relevant aqueous thermodynamics of copper and its oxides are evaluated and summarized with emphasis on solubility, hydrolysis, and complexation. The solubilities of metallic copper, solid cuprous and cupric oxides in steam measured by Pocock and Stewart in 1963 are discussed and the latter data are fitted in the form of established empirical equations and compared to other existing results. No other sources of data were found for the solubility of copper and cupric oxide in steam and even these data are very limited. Discussion of corresponding available solubility data on both oxide phases in liquid water is given. The possible effects of complexing agents are considered. A brief discussion is provided of the role of surface adsorption in determining the fate of dissolved copper in the boiler. 37 refs., 5 figs., 3 tabs.

Palmer, D.A.; Simonson, J.M.; Joyce, D.B.

1996-08-01T23:59:59.000Z

62

Dendrimer-encapsulated metal nanoparticle thin films on solid surfaces: preparation, characterization, and applications to electrocatalysis  

E-Print Network (OSTI)

Dendrimer-encapsulated nanoparticles (DENs) were prepared, characterized, and immobilized on solid surfaces. The resulting films were applied as electrocatalysts for the oxygen reduction reaction (ORR). First, the synthesis, physical and chemical properties, and stability of Pd DENs prepared within poly(amidoamine) (PAMAM) dendrimers were studied in aqueous solution. In this part of the study, the following new findings were reported: (1) the maximum Pd ion loading in the dendrimer was correlated to the number of interior amines available for complexation; (2) Pd DENs could be synthesized within amine-terminated Pd DENs by controlling the solution pH; (3) the oxidative stability of Pd DENs was significantly improved by removing solution-phase impurities; (4) exposure to hydrogen gas reversibly converts partially oxidized Pd DENs back to the zerovalent state. Second, Pt and Pd DENs were prepared using amine-terminated PAMAM dendrimers, and then the free amine groups on the periphery were used to immobilize Pt and Pd DENs onto Au surfaces via an intermediate self-assembled monolayer. The resulting DEN films were more robust and had higher coverages of DENs compared to the DEN films prepared via physisorption. Third, Pt DENs were prepared and immobilized on glassy carbon electrodes using an electrochemical coupling method. The resulting films were electrochemically active for the ORR. These electrocatalytic monolayers were also robust, surviving up to 50 consecutive electrochemical scans for ORR and sonication in acid solution with no significant change in activity. Finally, PtPd bimetallic nanoparticles containing an average of 180 atoms (~1.8 nm in diameter) and composed of seven different Pt:Pd ratios were prepared within sixth-generation, hydroxyl-terminated PAMAM dendrimers. Transmission electron microscopy and single-particle energy dispersive spectroscopy confirmed the sizes and compositions of the particles. These DENs were immobilized on glassy carbon electrodes, and their electrocatalytic properties were evaluated as a function of composition using cyclic voltammetry and rotating disk voltammetry. The results showed that the maximum rate for the ORR occurs at a Pt:Pd ratio of 5:1, which corresponds to a relative mass activity enhancement of 2.5 compared to otherwise identical monometallic Pt nanoparticles.

Ye, Heechang

2006-12-01T23:59:59.000Z

63

Published on Web 10/28/2008 Gas-Phase, Bulk Production of Metal Oxide Nanowires and Nanoparticles Using a Microwave Plasma Jet Reactor  

E-Print Network (OSTI)

We report gas-phase production of metal oxide nanowires (NWs) and nanoparticles (NPs) using direct oxidation of micron-size metal particles in a high-throughput, atmospheric pressure microwave plasma jet reactor. We demonstrate the concept with production of SnO2, ZnO, TiO2, and Al2O3 NWs. The results suggest that the NW production primarily depends upon the starting metal particle size, microwave power, and the gas-phase composition. The resulting NW powders could be separated from the unreacted metal and metal oxide NPs by sonication in 1-methoxy 2-propanol followed by gravity sedimentation. The experiments conducted using higher microwave powers resulted in spherical, unagglomerated, metal oxide NPs. The results obtained using various metal oxides suggest that the mechanism of NW nucleation and growth in the gas phase is similar to that observed in experiments with metal particles supported on substrates. A simplified analysis suggests that the metal powders melt in the plasma primarily with the heat generated from chemical reactions, such as radical recombination and oxidation reactions on the particle surface.

Jeong H. Kim; Rashekhar Pendyala; Boris Chernomordik; Mahendra K. Sunkara

2008-01-01T23:59:59.000Z

64

Copper and Copper Alloys  

Science Conference Proceedings (OSTI)

Table 1   Copper tube: types, standards, applications, tempers, and lengths...12 (3.658) 12 (3.658) HVAC Coils: Snow melting Compressed air 1/8 to 1 (3.175 to 25.4) ? 60 (18.288) ? Natural gas 100 (30.48) Liquified petroleum (LP) gas 1-1/4 & 1-1/2 (31.75 & 38.1) ? 60 (18.288) Vacuum 2 (50.8) ? 40 (12.192) ? 45 (13.716) Type L Blue ASTM B 88 Domestic water Straight lengths: service...

65

Determining the Behavior of RuO(x) Nanoparticles in Mixed-Metal Oxides:  

NLE Websites -- All DOE Office Websites (Extended Search)

Mechanism of Ethanol Synthesis from Syngas on Rh(111) Understanding of Mechanism of Ethanol Synthesis from Syngas on Rh(111) Understanding of ethanol decomposition on Rh(1 1 1) from density functional theory and kinetic Monte Carlo simulations Theoretical perspective of alcohol decomposition and synthesis from CO2 hydrogenation