硅酸乙酯为原料反相微乳液法制备纳米二氧化硅

Preparation of Silica Nanoparticles from Ethyl Silicate in Reverse Microemulsions

采用NP-5/环己烷/去离子水体系制备反相微乳液,绘制了该体系的三元相图,并以正硅酸乙酯(TEOS)为原料,在碱性条件下受控水解反应制备了纳米SiO2粒子,探讨了[n(水)∶n(表面活性剂)](用R表示)和[n(水)∶n(TEOS)](用H表示)对SiO2纳米粒子粒径的影响。通过扫描电镜(SEM)和激光粒度仪对样品形貌和粒子大小和粒径分布进行了表征。结果显示:扫描电镜下观察到的SiO2粒子为无定型球形颗粒,粒径在200～500 nm的范围,激光粒度仪分析得到的平均粒径随着R和H的增大而增大。

Reverse microemulsion of NP-5 /cyclohexane / water system was prepared,and the ternary phase diagram was drawn.The silica nanoparticles were synthesized by controlling hydrolysis of ethyl silicate（TEOS） in the recerse microemulsion.The effects of H2O /NP-5 molar ratio（R） and H2O /TEOS molar ratio（H） on the size of the resulting silica particles were studied.The morphologies of prepared samples were characterized by SEM,and the size and particle distribution were confirmed by laser granulometry.The results show that the synthesized particles are amorphous sphere silica particles with the size of 200—500 nm.The average particle size of silica determined by laser granulometry is increased with both increasing R and H.