Materials & Coatings

Nanorod-Based Fast-Response Pressure-Sensitive Paints

Improved, nanostructured coatings could be used to measure rapid pressure fluctuations. A proposed program of research and development would be devoted to exploitation of nanomaterials in pressuresensitive paints (PSPs), which are used on wind-tunnel models for mapping surface pressures associated with flow fields. Heretofore, some success has been achieved in measuring steady-state pressures by use of PSPs, but success in measuring temporally varying pressures has been elusive because of the inherent slowness of the optical responses of these materials.

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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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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 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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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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Removing Bioactive Contaminants by Use of Atomic Oxygen

Bioactive contaminants are removed without using liquid chemical baths or high temperatures. A method of removing endotoxins and other biologically active organic compounds from the surfaces of solid objects is based on exposure of the objects to monatomic oxygen generated in oxygen plasmas. The mon- atomic oxygen reacts strongly and preferentially with the organic contaminants to form volatile chemical species. The method was developed especially for removing such contaminants as lipopolysaccharides, proteins, lipids, and other biologically active contaminants from surfaces of orthopedic implants prior to sterilization and implantation; if not removed, these con- taminants can contribute to inflammation that sometimes necessitates the surgical removal of the implants.

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Glass/BNNT Composite for Sealing Solid Oxide Fuel Cells

Boron nitride nanotubes contribute to strength and fracture toughness. A material consisting of a barium calcium aluminosilicate glass reinforced with 4 weight percent of boron nitride nanotubes (BNNTs) has shown promise for use as a sealant in planar solid oxide fuel cells (SOFCs). The composition of the glass in question in mole percentages is 35BaO + 15CaO + 5Al2O3 + 10B2O3 + 35SiO2. The glass was formulated to have physical and chemical properties suitable for use as a planar- SOFC sealant, but has been found to be deficient in one aspect: it is susceptible to cracking during thermal cycling of the fuel cells. The goal in formulating the glass/BNNT composite material was to (1) retain the physical and chemical advantages that led to the prior selection of the barium calcium aluminosilicate glass as the sealant while (2) increasing strength and fracture toughness so as to reduce the tendency toward cracking.

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