Interweaved Cellular Structured Ceramic Nanofibrous Aerogels with Superior Bendability and Compressibility

Abstract

AbstractCeramic aerogels are attractive candidates for thermal insulation systems in spaceships, missiles, and aircrafts. However, the general lack of mechanical stability in conventional ceramic aerogels presents a major challenge for their practical applications. To date, the creation of mechanically robust ceramic aerogels has not made significant progress. Herein, a universal strategy is presented to fabricate ceramic nanofibrous aerogels with both superior bendability and compressibility, by assembling flexible silica nanofibers with a high length‐to‐diameter ratio into a highly continuous interwoven cellular structure. The resulting aerogels, with improved structural continuity, exhibit enhanced mechanical properties including large compression and buckling strain recovery (85%), temperature‐invariant superelasticity (from −196 °C to 1100 °C), and robust fatigue tolerance up to 100 000 cycles. In parallel, the low thermal conductivity (0.0223 W m−1 K−1), as well as exceptional high‐temperature thermal insulation performance enable them to be ideal candidates for thermal insulation in extreme environments. The successful synthesis of this material may shed light on the development of other mechanically robust ceramic aerogels.