Materials

Polyaniline Compounds for Protection Against Corrosion

Protective surface layers can be formulated and applied in various ways. Corrosion of iron and steel substrates can be inhibited by coating them with any of the wide variety of compounds denoted generally as polyanilines. A polyaniline suitable for this type of application can be in either an electrically conductive salt (doped) form or an electrically nonconductive base form. Typically, polyaniline is dissolved in an organic solvent and the resulting solution is applied to a substrate by spraying, dipping, or brushing. The solvent is then allowed to evaporate leaving the substrate coated with a solid film of polyaniline, typically 1 to 200µm thick.

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Composite-Matrix Regenerators for Stirling Engines

One can exploit the properties of composites to reduce thermal and flow losses. A prototype Stirling-engine regenerator containing a matrix made of carbon-fiber-based composite materials has been developed. The concept underlying this development effort is one of exploiting the properties of composite materials (e.g., the anisotropy of thermal conductivity of carbon fibers and the tailorability of composite materials and structures) to reduce thermal and flow losses below those of previously developed regenerators containing metal matrices.

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Photocatalytic/Magnetic Composite Particles

Magnetic agitation enhances effectiveness. Photocatalytic/ magnetic composite particles have been invented as improved means of exploiting established methods of photocatalysis for removal of chemical and biological pollutants from air and water. The photocatalytic components of the composite particles are formulated for high levels of photocatalytic activity, while the magnetic components make it possible to control the movements of the particles through the application of magnetic fields. The combination of photocatalytic and magnetic properties can be exploited in designing improved air- and water-treatment reactors.

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Water-Free Proton-Conducting Membranes for Fuel Cells

Fuel cells could be operated at higher temperatures for greater efficiency. Poly-4 -vinylpyridinebisulfate (P4VPBS) is a polymeric salt that has shown promise as a water-free proton-conducting material (solid electrolyte) suitable for use in membrane/electrode assemblies in fuel cells. Heretofore, proton-conducting membranes in fuel cells have been made from perfluorinated ionomers that cannot conduct protons in the absence of water and, consequently, cannot function at temperatures >100 °C. In addition, the stability of perfluorinated ionomers at temperatures >100 °C is questionable. However, the performances of fuel cells of the power systems of which they are parts could be improved if operating temperatures could be raised above 140 °C. What is needed to make this possible is a solidelectrolyte material, such as P4VPBS, that can be cast into membranes and that both retains proton conductivity and remains stable in the desired higher operating temperature range.

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Making Single-Source Precursors of Ternary Semiconductors

Commercially available reagents are used in a simplified synthesis. &A synthesis route has been developed for the commercial manufacture of single- source precursors of chalcopyrite semiconductor absorber layers of thin-film solar photovoltaic cells. The semiconductors in question are denoted by the general formula CuInxGa1–xSySe2–y, where 0≤x≤1 and 0≤y≤1.

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Norbornene-Based Polymer Electrolytes for Lithium Cells

These solid electrolytes are single-ion conductors. Norbornene-based polymers have shown promise as solid electrolytes for lithium-based rechargeable electrochemical cells. These polymers are characterized as single-ion conductors.

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Making Ternary Quantum Dots From Single-Source Precursors

Relative to a prior process, this process is simpler and safer. A process has been devised for making ternary (specifically, CuInS2) nanocrystals for use as quantum dots (QDs) in a contemplated next generation of highefficiency solar photovoltaic cells. The process parameters can be chosen to tailor the sizes (and, thus, the absorption and emission spectra) of the QDs.

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