低密度SiO_2气凝胶的常压制备工艺

Preparation process of low density silica aerogels by ambient pressure drying

为了制备低密度的SiO_2气凝胶,采用溶胶凝胶法,在常压干燥条件下,经酸碱两步催化制得SiO_2气凝胶.通过探讨不同工艺条件对SiO_2气凝胶密度的影响,最终确定了最佳工艺:无水乙醇/正硅酸乙酯摩尔比为7,水/正硅酸乙酯摩尔比为5,pH值为7,反应温度为55℃,转速为100r/min.结果表明,此时SiO_2气凝胶的密度最小为0.28g/cm^3.

In order to prepare low density SiO2 areogel, in ambient pressure drying condition, the sol-gel method and the acid and alkali two-step catalysis are used to produce SlOe areogel. By discussing the influence of different process conditions on the density of SiO2 aerogel, then the best techniques are found out that molar ratio of EtOH/TEOS is 7, molar ratio of H2O/ TEOS is 5,pH value is 7,temperature is 55℃and rotate speed is 100r/min. Results show that the density of SiO2 areogel is 0. 28g/cm3.