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SiO2 气凝胶是一种新型轻质纳米多孔材料。本工作以多聚硅氧烷 (E -4 0 )为硅源 ,用溶胶 -凝胶法制备出了SiO2气凝胶。研究了催化剂、温度、水等因素对其溶胶 -凝胶过程的影响 ;讨论了F离子以及水对E -4 0水解 -缩聚反应的作用机理 ;并用孔径分布测定仪、TEM等方法对其微结构进行了研究。结果表明 :由E -4 0为硅源制备的SiO2 气凝胶骨架颗粒为十几nm ;孔径分布较广 ,其峰值在 3 0nm附近 ,此外 ,还存在几nm的微孔。
Silica airgel is a new lightweight nanoporous material. In this work, aerogels were prepared by sol-gel method using polysiloxane (E-40) as silica source. The effects of catalyst, temperature, water and other factors on the sol-gel process were studied. The mechanism of hydrolysis and polycondensation reaction of F-ions and water on E -4 0 was discussed. Structure was studied. The results show that SiO2 aerogels prepared from E-40 as silica source have more than a dozen nm particles, a wide pore size distribution and a peak near 30 nm. In addition, there are several nm pores.