Abstract: SiO₂ aerogels have outstanding performance in quality of heat insulation and preservation for its nano-porous microstructure. However, the poor mechanical properties of SiO₂ aerogels restrict its application in many industrial fields. In this paper, aluminosilicate fiber is used as reinforcement to strength the skeleton of SiO₂ aerogels, and a kind of aluminosilicate fiber/SiO₂ aerogels composites was prepared by sol-gel method and atmospheric pressure drying. The microstructure and properties of the composites are characterized by SEM, universal testing machines, thermal conductivity meter and BET. The results indicate that the adding of aluminosilicate fiber provide a new energy expenditure mechanism for the composites under applied force, and the mechanical property of the composites are increased efficiently. The surface area and average pore diameters of the composites are 383.5 m²/g and 8.4 nm, respectively, and the porosity is 87%, belonging to typical mesopore material. At the same time, the thermal conductivity of composites is as low as 0.02 W/(m·K)~0.04 W/(m·K), indicating their good thermal-insulating performance.

Key words: SiO₂ aerogels, aluminosilicate fiber, mechanical properties, thermal conductivity