二氧化硅气凝胶的制备和表征  

Preparation and characterization of silica aerogels

作　　者：刘朝辉[1] 苏勋家[1] 侯根良[1] 王德朋[1] 

机构地区：[1]第二炮兵工程学院,陕西西安710025

出　　处：《无机盐工业》2006年第7期25-27,共3页Inorganic Chemicals Industry

摘　　要：以正硅酸四乙酯为硅源,通过采取老化、表面修饰、溶剂置换和分级干燥等一系列抑制二氧化硅气凝胶干燥中出现缩裂的有效措施,以非超临界干燥技术最终获得了大块无裂纹的二氧化硅气凝胶。该气凝胶的孔径较小且分布均匀,比表面积为684 m2/g,孔体积可达1.38 cm3/g,最可几孔径为3.221 nm,平均孔径达2.871 nm。同时在实验和理论分析的基础上总结了二氧化硅气凝胶缩裂的主要原因和抑制缩裂的有效措施。Taking tetraethyl orthosilicate（TEOS） as the resouces of silica and adopting a series effective measures, such as ageing, surface modifying, solvent replacement and fractional drying to avoid the crack of the aerogels in drying process, the big and non - cracked silica aerogels are prepared by non - supercritical drying. The apertures of the silica aerogels are small and well -proportionated, its specific surface area is 684 m^2/g, and the pore volume is 1.38 cm^3/g, the most possible aperture is 3. 221 nm, the average aperture is 2. 871 nm. This article also summarized the main reasons for the cracks and some effective measures to restrain the cracks based on experiments and theoretical analysis.

关 键 词：二氧化硅 气凝胶 非超临界干燥 

分 类 号：TQ127.2[化学工程—无机化工] TQ427.26