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Title: Nanostructured surfaces for microfluidics and sensing applications.

Abstract

The present work demonstrates the use of light to move liquids on a photoresponsive monolayer, providing a new method for delivering analyses in lab-on-chip environments for microfluidic systems. The light-driven motion of liquids was achieved on photoresponsive azobenzene modified surfaces. The surface energy components of azobenzene modified surfaces were calculated by Van Oss theory. The motion of the liquid was achieved by generation of a surface tension gradient by isomerization of azobenzene monolayers using UV and Visible light, thereby establishing a surface energy heterogeneity on the edge of the droplet. Contact angle measurements of various solvents were used to demonstrate the requirement for fluid motion.

Authors:
 [1];  [2]; ;  [1];  [1]; ; ;  [1];  [1]
  1. (Arizona State University)
  2. (United Technologies Corp.)
Publication Date:
Research Org.:
Sandia National Laboratories
Sponsoring Org.:
USDOE
OSTI Identifier:
902205
Report Number(s):
SAND2006-7632
TRN: US200717%%422
DOE Contract Number:
AC04-94AL85000
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; LIQUID FLOW; MINIATURIZATION; VISIBLE RADIATION; AZO COMPOUNDS; ISOMERIZATION; SURFACE ENERGY; SURFACE TENSION; ULTRAVIOLET RADIATION; Nanostructure materials.; Systems on a chip.; Nanotechnology.; Microfluidic devices*

Citation Formats

Picraux, Samuel Thomas, Piech, Marcin, Schneider, John F., Vail, Sean, Hayes, Mark A., Garcia, Anthony A., Bell, Nelson Simmons, Gust, D, and Yang, Dongqing. Nanostructured surfaces for microfluidics and sensing applications.. United States: N. p., 2007. Web. doi:10.2172/902205.
Picraux, Samuel Thomas, Piech, Marcin, Schneider, John F., Vail, Sean, Hayes, Mark A., Garcia, Anthony A., Bell, Nelson Simmons, Gust, D, & Yang, Dongqing. Nanostructured surfaces for microfluidics and sensing applications.. United States. doi:10.2172/902205.
Picraux, Samuel Thomas, Piech, Marcin, Schneider, John F., Vail, Sean, Hayes, Mark A., Garcia, Anthony A., Bell, Nelson Simmons, Gust, D, and Yang, Dongqing. Mon . "Nanostructured surfaces for microfluidics and sensing applications.". United States. doi:10.2172/902205. https://www.osti.gov/servlets/purl/902205.
@article{osti_902205,
title = {Nanostructured surfaces for microfluidics and sensing applications.},
author = {Picraux, Samuel Thomas and Piech, Marcin and Schneider, John F. and Vail, Sean and Hayes, Mark A. and Garcia, Anthony A. and Bell, Nelson Simmons and Gust, D and Yang, Dongqing},
abstractNote = {The present work demonstrates the use of light to move liquids on a photoresponsive monolayer, providing a new method for delivering analyses in lab-on-chip environments for microfluidic systems. The light-driven motion of liquids was achieved on photoresponsive azobenzene modified surfaces. The surface energy components of azobenzene modified surfaces were calculated by Van Oss theory. The motion of the liquid was achieved by generation of a surface tension gradient by isomerization of azobenzene monolayers using UV and Visible light, thereby establishing a surface energy heterogeneity on the edge of the droplet. Contact angle measurements of various solvents were used to demonstrate the requirement for fluid motion.},
doi = {10.2172/902205},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}

Technical Report:

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  • No abstract prepared.
  • A class of ceramics, capable of exhibiting low coefficients of thermal expansion and catalytic properties was investigated. Investigations were directed towards nanoengineering of NZP ceramics and NZP-based composites by chemical means by controlling their compositions and processing variables. NaZr{sub 2}(PO{sub 4}){sub 3} (NZP) was synthesized by combining water-soluble precursors leading to the precipitation of a gel that was dried, calcined, pressed into pellets, then fired at 850 C. Without chemical additives, the resulting ceramic comprised pores ranging in size from approximately 25 to 50 nm and a surface area of about 30m{sup 2}/g. Hydroxyapatite, which has a needle-like morphology, wasmore » mechanically mixed with the calcined gel to template NZP crystallization. What resulted was a coarsening of the pore structure and a decrease in surface area. When copper nitrate was added to the solution during synthesis, the resulting ceramic underwent shrinkage upon firing as well as an increase in strength. HAp and copper additions combined resulted in 40% volume shrinkage and a doubling of the tensile strength to 16MPa. A very different type of porosity was achieved when silica was partly substituted for phosphorous in the NZP structure. Na{sub 3}Zr{sub 2}(Si{sub 2}P)O{sub 12} (NASCION) was synthesized in the same manner as NZP, but the fired ceramic possessed a reticulated pore structure comprising large cavities ranging in size from 5 to 50 {micro}m. The NASCION ceramic either shrank or expanded upon firing depending on when the silica was added during synthesis. When the silica precursor (amorphous, precipitated silica) was added before the calcining step, the pressed pellets expanded during firing, whereas they shrank when the silica was added after the gel was calcined. The observed dilation increased with increasing calcining temperature and particle size, up to 26%. The contraction of the ceramic when fired increased with increasing calcining temperature and a greater surface area of the gel. Direct addition of Silica fiber was only modestly beneficial. Fiber addition combined with controlled densification resulted in the greatest improvement in strength. Ion exchange properties of NASICON were established for Cs, Pb, and Cd. It was found that the extent of ion exchange depended on ion size and that Cd could be fully exchanged into NASICON. Catalytic activity of Cu and Ag substituted compositions were determined and it was found that Ag substitution reduced the temperature at which carbon black could be oxidized. However, Ag substitution results in the formation of zircon. Ion conductivity of NASCION was determined and it was found to compare well with other ionic conductors.« less
  • This report summarizes the results obtained from a Laboratory Directed Research & Development (LDRD) project entitled 'Investigation of Potential Applications of Self-Assembled Nanostructured Materials in Nuclear Waste Management'. The objectives of this project are to (1) provide a mechanistic understanding of the control of nanometer-scale structures on the ion sorption capability of materials and (2) develop appropriate engineering approaches to improving material properties based on such an understanding.