水玻璃-乙酸乙酯体系的成胶特性及SiO_2凝胶粉末的制备

THE GELLING CHARACTERISTIC OF WATER GLASS-ETHYL ACETATE SYSTEM AND THE PREPARATION OF SILICA POWDER

通过乙酸乙酯和水玻璃溶液的相互作用 ,用溶胶 -凝胶法制备超细SiO2 凝胶粉末 .研究了水玻璃 -乙酯乙酯反应体系的成胶特点 ,考察了乙酸乙酯用量对SiO2 凝胶粉末颗粒粒径及孔结构性质的影响 .结果表明 :当成胶体系中乙酸乙酯 /SiO2 摩尔比在 0 .67～ 0 .82时 ,可制得粒径为 1 5～ 2 5nm超细SiO2 凝胶粉末 ,粉末的BET比表面积为 3 70～ 4 2 0m2 /g ,主要孔径分布范围为 1 0～ 1 0 0nm .

By the interaction of ethyl acetate and water glass solution, superfine silica powder was prepared with sol-gel method. The gelling characteristic of water glass-ethyl acetate system was studied and the effect of amount of ethyl acetate added in the gelling process on the particle size and pore structure of silica powder was investigated. The experimental results show that when the mole ratio of ethyl acetate to silica is 0.67 —0.82, superfine silica powder with particle size in the range of 15—25 nm, BET specific surface area 370—420 m 2/g and pore size distribution between 10—100 nm can be obtained.