应用扫描电镜研究反相胶束法合成介孔二氧化硅微球

Abstract

以十六烷基三甲基溴化胺(CTAb)为模板,采用反相胶束法合成不同粒径的二氧化硅微球,并利用扫描电镜(SEM)对所制备的微球进行表征.考察了体系中乙醇/水比例、氨水用量、CTAb用量、温度和搅拌速度这5个条件对所制备的二氧化硅微球的粒径、均一性及分散性的影响.实验结果表明:增加体系中乙醇/水的比例将减小纳米颗粒的粒径,同时显著提高纳米颗粒的均一性和分散性;随着氨水用量的增加,微球的粒径先减小后增加,适当的氨水浓度有利于制备粒径均一的微球;增加CTAb的用量,微球的粒径增加;降低反应温度有利于合成大粒径、均一性好的微球;同时,提高搅拌速度也有利于制备均一性良好的微球.

Silica nanoparticles with different diameters were synthesized by reverse micelle method using CTAB as template and were characterized by SEM.The effects of the ethanol/water ratio,the amounts of ammonia and CTAB,the temperature and the stir speed on the size,uniformity and dispersibility of the prepared silica nanoparticles were fully studied,respectively.The results demonstrated that increasing the ethanol/water ratio would decrease the nanoparticles' size with markedly improved uniformity.Increasing the amount of ammonia led to an initiative decrease and succedent increase to the size of the nanoparticles.Appropriate amount of ammonia was propitious to nanoparticles with good uniformity and dispersion.More CTAB also led to increased size of the silica nanoparticles.Furthermore,lower temperature was found to be favorable to formation of bigger and more monodisperse silica nanoparticles,and higher stir speed was also found to be effective for formation of nanoparticles with good uniformity and dispersibility.