Lightweight and Resilient ZrO2–TiO2 Fiber Sponges with Layered Structure for Thermal Insulation

Low density, heat-resistant sponge-like fiber assembly materials are considered as promising high-temperature insulation materials. However, the poor structural stability, infrared radiation heat transfer, and complex preparation process limit its further application. Herein, a facile method to create ultralow-density ZrO 2 –TiO 2 fiber sponges by the electrospinning method followed by heat treatment is presented. The layered structure sponges treated at 1200 °C have a low density of 9.5 mg cm −3 . Moreover, the sponges possess high compressibility and good compression resistance over a wide temperature range from −196 to 1200 °C. In addition, the sponges exhibit low thermal conductivity of 27 mW m −1 K −1 , robust fire resistance, and high near-infrared reflectance, making them an ideal alternative for high-temperature thermal insulation materials.