Silica aerogel powder was prepared from industrial silica sols by ambient pressure drying and controlling the gelatin process and drying conditions. The effects of tetraethoxysilane (TEOS) content in aging solution and the drying control chemical additive (DCCA) on the density, specific surface,and pore size distribution of the SiO2 aerogel powder were investigated. The results show that; ( 1 ) the aerogels are nano-porous net structure of the spherical primary nanoparticles of 10-25 nm and the nano-metric pores of 5-50 nm;(2)With the temperature rising from room temperature to 1 100 ℃,the silica aerogels change from the amorphous phase to cristobalite; (3)the nano-network of silica aerogel powder can be strengthened by aging in mixture of TEOS and ethanol;(4)the addition of DCCA can improve the pore size distribution and increase the specific surface area of silica aerogel powders.%以工业硅溶胶为原料,通过凝胶过程与干燥条件的控制,采用常压干燥法制备了SiO2 气凝胶粉体,并考察了老化液中正硅酸乙脂(TEOS)含量和干燥控制化学添加荆甲酰胺的添加对气凝胶粉体堆积密度、比表面积和孔径分布的影响.结果表明:所得气凝胶粉体具有纳米多孔结构,组成气凝胶结构的基本粒子呈圆球形,粒径为10～25 nm,由基本粒子连接而成的网络结构具有5～50 nm的孔径分布;随着热处理温度从常温升至1 100℃,SiO2气凝胶从最初的无定形态转化为方石英;在,TEOS的醇溶液中老化,有利于增强凝胶骨架的强度;添加甲酰胺可以改善气凝胶粉体的孔径分布,提高其比表面积.
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