Al2O3/SiO2 sponges with a three-dimensional lamellar structure based on solution blow spinning for superior thermal insulation and high temperature filtration

Ceramic nanofiber sponges offer excellent resistance to temperature and corrosion resistance, rendering them suitable for various applications in heat insulation, sound absorption, and high-temperature filtration. However, traditional ceramic nanofibers are difficult to prepare and are inherently brittle at high temperatures, which significantly limits their development. Therefore, this study proposes a method of fabricating SiO 2 /Al 2 O 3 nanofiber (SANF) sponges using sol–gel processing and electrostatically assisted solution blow spinning (E-SBS). The prepared SANF sponges have a low density (10.63 mg cm −3 ), high compressibility, and low thermal conductivity. Moreover, they have excellent flexibility at − 196 ∼ 1300 °C, a strain-independent zero Poisson’s ratio, and good compression resilience without structural damage. Furthermore, with their low thermal conductivity (0.026 W m −1 K −1 ) and has good interception efficiency (> 99.3 %) against particles of different diameters at 1000 ℃. After undergoing electrostatic removal treatment, the SANF sponge demonstrates remarkable performance stability, maintaining filtration efficiency above 98 % while achieving an exceptional dust holding capacity of 101.2 g m −2 through 40 days of continuous operation. This breakthrough performance represents a significant advancement over conventional nanofiber membrane materials, which have historically suffered from limited dust retention capabilities. We prepared SANF sponges are promising candidates to replace existing thermal insulation and high temperature filtration materials, providing new insights for the development of next-generation thermal insulation and high temperature filtration materials.