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Originally developed as a flexible thermal protection system (FTPS), this BNNT mat was designed to shield a 40-ton craft from the high aerothermal flux of atmospheric entry, descent, and landing. The novel lightweight flexible BNNT mat is an excellent flame retardant material and has shown excellent thermal stability and shielding capabilities under a hypersonic thermal flux test in air. The novel BNNT mat or fabric creates an in-situ passivation layer under high thermal flux which minimizes penetration of the atmosphere (air or gas) as well as heat and radiation through the thickness. BNNT effectively diffuses heat throughout the mat or fabric laterally and radially to minimize localized excessive heat. In addition, the lightweight flexible BNNT mat can efficiently alleviate the heat via radiation because of its high thermal emissivity. This invention offers a lightweight, simple, single layer BNNT FTPS with better thermal protection and flame retardation performance in extreme environments while providing structural robustness. The novel BNNT materials can also serve as flame retardants and flame retardant additives in composite systems that are also potentially more colorable compared to carbon nanotube additives.

Sometimes called white graphite, affordable and plentiful hBN possesses the same kind of layered molecular structure as graphite. In graphite, this structure has allowed next-generation nanomaterials like carbon nanotubes and graphene to be produced. With hBN, however, the process of converting the substance into boron nitride nanotubes (BNNT) has been too difficult to yield commercial quantities. Glenn innovators have created several new methods that could enable greater adoption of this unique nanomaterial. In the initial stage, the starter reactant is mixed with a selected set of chemicals (a metal chloride, for example) and an activation agent (such as sodium fluoride). This mixture causes hBN to become less resistant to intercalation. The intercalated product can then be exfoliated by heating the material in air, and giving the material a final rinse with a liquid-phase ferric chloride salt to dissolve any embedded impurities without damaging its internal structure. These efficiently exfoliated nanomaterials can be used to form advanced composite materials (e.g., layered with aluminum oxide to form hBN/alumina ceramic composites). Nanomaterials fabricated from hBN can also take advantage of the material's unique combination of being an electrical insulator with high thermal conductivity for applications ranging from microelectronics to energy harvesting. Glenn's innovations have enabled a significantly improved matrix composite material with the potential to make a significant impact on the commercial materials market.