超临界干燥法制备SiO_2气凝胶的研究

Preparation of Silica Aerogels by Supereritical Drying Technique

通过溶胶－凝胶法和超临界干燥技术制得了ＳｉＯ２气凝胶。研究了溶液的ｐＨ值对凝胶时间及气凝胶密度的影响。应用ＸＲＤ、ＳＡＸＳ、ＴＥＭ和等方法对气凝胶样品的结构进行了初步研究。结果表明，ＳｉＯ２气凝胶是连续网络的非晶态纳米多孔固体，其基本粒子的平均直径约１０ｎｍ。

Silica aerogels were prepared by sol-gel process and supercritical drying technique.The effects of the pH value of solution on the gelation time and the density of the aerogel samples were studied.Through XRD, SAXS,TEM and some other experimental methods,the structure of silica aerogel samples was primarily investigated. The results show that the silica aerogels were coherent,non-crystalline,nanosized porous solids.The mean diameter of particles is about l0 nm.