Aerogels hold promise as lightweight replacements for thermal insulation, but poor mechanical stability has slowed the maturation of these materials. Extended cycles of heating and cooling can result in the fracturing of ceramic aerogels.

A new aerogel composed of thin layers of boron nitride shows improved durability and flexibility after repeated The lightweight ceramic aerogel can rest on a flower without damaging it. Source: Xiangfeng Duan and Xiang Xu/University of California Los AngelesThe lightweight ceramic aerogel can rest on a flower without damaging it. Source: Xiangfeng Duan and Xiang Xu/University of California Los Angelesexposure to sharp thermal shocks. Unlike other ceramic materials, this aerogel material contracts rather than expands when heated, and also contracts perpendicularly to the direction that is compressed.

The key to these useful properties is the aerogel’s architecture: its atomic structure is arranged in a hexagonal, double-pane pattern that reduces weight while boosting insulation capacity. After exposure to temperature swings in the -198° C and 900° C (-324° F and 1,652° F) range, and being subjected to 1,400° C (2,552° F) for a week, the material lost only 1% of its mechanical strength.

The international research team considers this robust material system ideal for thermal superinsulation under extreme conditions, such as those encountered by spacecraft.

Researchers from the University of California Los Angeles, Harbin Institute of Technology (China), Lanzhou University (China), University of California Berkeley, Southeast University (China), Hunan University (China), New Jersey Institute of Technology, Purdue University, King Saud University (Saudi Arabia) and Lawrence Berkeley National Laboratory contributed to this development.

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