Mullite Nanosheet/Titania Nanorod/Silica Composite Aerogels for High-Temperature Thermal Insulation

Ceramic aerogels play an essential role in the field of high-temperature insulation. However, the significant radiation heat transfer limits the practical applicability. Herein, we have chosen mullite nanosheets prepared successfully by chemical blowing as structural assembly units, modified on the surface of mullite nanosheets with TiO2 nanorods to reduce infrared radiation heat transfer, and prepared mullite nanosheet/TiO2 nanorod/silica composite aerogels by adding silica sols as high-temperature binder cast molding in the system. The preferred composite aerogels have good temperature resistance, and the linear shrinkage was measured to be only 2% after calcination at 1500 °C for 30 min and had a low thermal conductivity (0.0356 W·m–1·K–1 at room temperature and 0.118 W·m–1·K–1 at 1000 °C). This assembly concept pervades a strategy for developing porous aerogel materials for insulation and protection in extreme environments.