（College of Materials Science & Engineering, South China University of Technology, Guangzhou 51CHARACTERIZATION OF SiO2 AEROGELS/FIBER COMPOSITES

PREPARED BY THE SOL-GEL METHODS0640）

Abstract:SiO₂ aerogels/fiber composites were prepared by sol -gel process and drying under ambient pressure using tetraethoxysilane (TEOS) as precursor, chlorhydric acid and hartshorn as catalysts, and ceramic fiber preform as reinforcement. The microstructures were characterized by scanning electron microscope (SEM), and the thermal properties were tested by hot plate method. The mechanisms of thermal properties of SiO₂ aerogels/fiber composites were analyzed.The results show that, SiO₂ aerogels/fiber composites with the properties of low thermal conductivity, low thermal diffusivity,low thermal capacity can be prepared by Sol-Gel process and vacuum technology, the inner space of the fiber preform wasfilled with SiO₂ aerogels, the thermal conductivity of the composites can reach 0.6815W/mK, while the thermal diffusivity was 0.2677mm²/s, and the thermal capacity was 0.2919MJ/m³K.

Keywords:aerogels, fiber, composites, thermal properties