Materials & Coatings

Development of Carbon-Nanotube/Polymer Composites

A report presents a short discussion of one company’s effort to develop composites of carbon nanotubes in epoxy and other polymer matrices.

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Multicomponent, Rare-Earth-Doped Thermal-Barrier Coatings

Thermal conductivities are reduced while maximum use temperatures are increased. Multicomponent, rare-earth-doped, perovskite-type thermal-barrier coating materials have been developed in an effort to obtain lower thermal conductivity, greater phase stability, and greater high-temperature capability, relative to those of the prior thermal-barrier coating material of choice, which is yttriapartially stabilized zirconia. As used here, “thermal-barrier coatings” (TBCs) denotes thin ceramic layers used to insulate air-cooled metallic components of heat engines (e.g., gas turbines) from hot gases. These layers are generally fabricated by plasma spraying or physical vapor deposition of the TBC materials onto the metal components.

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Reactive Additives for Phenylethynyl-Containing Resins

Processability is improved. Phenylethynyl containing reactive additive (PERA) compounds and mixtures have been found to be useful for improving the processability of oligomers, polymers, cooligomers, and copolymers that contain phenylethynyl groups. The additives can be incorporated in different forms:

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Multifunctional Deployment Hinges Rigidified by Ultraviolet

These hinges provide both structural support and electrical connections.

Posted in: Briefs, TSP

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Multi-Layer Laminated Thin Films for Inflatable Structures

Laminates offer advantages over equal-thickness monolayer sheets. Special-purpose balloons and other inflatable structures would be constructed as flexible laminates of multiple thin polymeric films interspersed with layers of adhesive, according to a proposal. In the original intended application, the laminate would serve as the envelope of the Titan Aerobot — a proposed robotic airship for exploring Titan (one of the moons of Saturn). Potential terrestrial applications for such flexible laminates could include blimps and sails.

Posted in: Briefs, TSP

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Nanostructured MnO2-Based Cathodes for Li-Ion/Polymer Cells

Experiments show promise for increasing energy densities. Nanostructured MnO2-based cathodes for Li-ion/polymer electrochemical cells have been investigated in a continuing effort to develop safe, highenergy-density, reliable, low-toxicity, rechargeable batteries for a variety of applications in NASA programs and in mass-produced commercial electronic equipment. Whereas the energy densities of state-of-the-art lithium-ion/polymer batteries range from 150 to 175 W·h/kg, the goal of this effort is to increase the typical energy density to about 250 W·h/kg. It is also expected that an incidental benefit of this effort will be increases in power densities because the distances over which Li ions must diffuse through nanostructured cathode materials are smaller than those through solid bulk cathode materials.

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Making Macroscopic Assemblies of Aligned Carbon Nanotubes

Nanotubes are aligned and manipulated with the help of magnetic and/or electric fields. A method of aligning and assembling single-wall carbon nanotubes (SWNTs) to fabricate macroscopic structures has been invented. The method entails suspending SWNTs in a fluid, orienting the SWNTs by use of a magnetic and/or electric field, and then removing the aligned SWNTs from suspension in such a way as to assemble them while maintaining the alignment.

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