Regulating the concentration of silica sol to prepare high thermal insulation ceramic nanofiber aerogel composites

Abstract

Abstract Ceramic aerogels can maintain excellent thermal insulation performance under extreme conditions due to their outstanding pore structure and specific surface area. However, the current application of ceramic aerogels is limited by their brittleness, easy collapse of the structure under external forces, and insufficient mechanical properties. In this study, ceramic nanofiber aerogels prepared by PEO as a polymer were used as building blocks, and silica sol was selected as a high-temperature binder. Through the sol impregnation-atmospheric pressure drying method and calcination treatment, we obtained ceramic nanofiber composites with excellent performance. It is found that when the impregnation concentration is 0.4wt%, the thermal conductivity at room temperature is as low as 27 m W·m-1·K-1, the cold surface temperature at 800°C is as low as 255°C, the tensile strength at 20% tensile strain is as high as 400 kPa, and the compressive strength at 80% compressive strain is as high as 32 kPa. Compared with the traditional ceramic fiber aerogel material, the material exhibits excellent high-temperature insulation performance and mechanical properties, which greatly broadens the application scene of ceramic aerogel.