反应条件对SiO_2溶胶粒径及粒径分布的影响

Effect of Reaction Conditions of Silica Sol on the Particle Size and Its Distribution

为考察溶胶-凝胶法SiO2溶胶制备中反应物比例及反应条件对溶胶粒径及粒径分布的影响,以正硅酸乙酯为前驱体,硝酸为催化剂制备了SiO2溶胶.结果表明,在保持其他反应条件不变的情况下,随着EtOH/TEOS摩尔比的增大,溶胶胶体粒径减小;随着H2O/TEOS摩尔比的增大,胶体粒径增大;pH<2时,随着HNO3/TEOS摩尔比的增大,胶体粒径变化不明显;反应温度的升高及反应时间的延长,都会促使溶胶胶体粒径增大.

Silica sol was prepared using TEOS as the precursor and HNO3 as the catalyst by sol-gel process. The effects of the ratio of the reactants and reaction conditions on the particle size and particle size distribution of SiO2 sols were inspected during the sol-gel processing in this paper. The results showed that with the increasing of EtOH/TEOS molar ratio, the particle size of sols had a reducing trend. With the increasing of H2O/TEOS molar ratio, the sol particle size of sols had a growing trend. With the increasing of HNO3/TEOS molar ratio, the particle size of sols did not change obviously when pH value is less than 2. Reaction tempeture raising and reaction time increasing could urge particle size to enhance.