低密度SiO_2气凝胶的制备及性质表征

通过二步溶胶－凝胶法和ＳＣＦＤ过程制备了低密度ＳｉＯ２气凝胶，并应用ＳＥＭ，自动吸附仪，元素分析仪对气凝胶样品进行了结构和性质表征，且分析了ＴＥＯＳ浓度和Ｈ２Ｏ／ＴＥＯＳ值对气凝胶结构和性质的影响。结果表明，用此方法可以制备密度低至０．０２ｇ·ｃｍ－３的ＳｉＯ２气凝胶，具有较高比表面积和孔体积，充满两端开放的管状中孔（ｒｐ＝１３．６ｎｍ），且含有少量以物理和化学状态结合的碳与氢。

Preparation and Characterization of Low Density SiO 2 Aerogel

Low density silica aerogels were prepared by two step Sol Gel method.The aerogel samples were characterized with Scanning Electron Microscope,Automatic Instrument of Adsorption and Element Analyzer.The effects of the concentration of TEOS and the molar ratio of H 2O/TEOS on the aerogel's structure and property were investigated.It is found that the aergoels have low desity ( ρ a=0.02 g·cm -3 ),large specific surface area and pore volume,a small quantity of carbon and hydrogen were combined with the aerogel.