Flexible fiber reinforced silica aerogel composites for thermal insulators were prepared by ammonia鄄
catalyzed one鄄step sol鄄gel process, using tetraethoxysilane as precursor, high silica fiber as reinforcement. The highest
specific surface area (SSA) can be obtained in an aerogel derived from the sol with pH=7. The SSA decreases with
increasing the water molar ratio, while it increases with increasing the ethanol molar ratio. When the molar ratio of
ethanol/ tetraethoxysilane is higher than 10, the SSA only increases mildly with increasing the ethanol ratio. The ther鄄
mal conductivity of the high silica fiber鄄reinforced high SSA aerogel composites is 0. 031 W/ (m·K )[0. 044 W/ (m·
K )for the high silica fiber matrix]. The flexible aerogel composites are easy鄄to鄄install and are very suitable for insula鄄
tions on large surfaces and complex shapes.