单因素对单分散二氧化硅微球制备的影响

Effect of Single Factor on Synthesis of Monodispersed Silicon Dioxide Spheres

以氨水为催化剂、正硅酸乙酯为硅源、醇为溶剂,采用改进的溶胶-凝胶工艺制备单分散SiO_2微球,通过扫描电镜、激光粒度分析仪着重研究了正硅酸乙酯添加方式、反应温度、溶剂类型等单因素对SiO_2的颗粒大小和形貌的影响。结果表明,正硅酸水解对醇溶剂是有选择性的,乙醇作为溶剂合成SiO_2的单分散性和球形度最好。连续滴定和分步滴定更有利于单分散SiO_2微球的形成。水解温度升高,生成的颗粒粒径将逐渐增大,最佳反应温度为常温25℃或恒温水浴25～35℃。

Monodispersed silicon dioxide spherical particles are synthesized by improved sol-gel methods, using ammonia as catalyst, tetraethoxy silane（TEOS） as silica source and ethanol as solvent. The effect of adding method, reaction temperature, solvent types of TEOS on the particle size and morphology of silicon dioxide is studied by scanning electron microscope（SEM） and laser particle size analyzer. The results show that hydrolysis of ortho silicate is selective to alcohol solvent, monodispersity and sphericity of silicon dioxide are best using ethanol as solvent, continuous titration and stepwise titration are more beneficial to the formation of monodispersed silicon dioxide spherical particles. The particle size increases gradually with the rise of hydrolysis temperature, the best reaction temperature is room tem- perature 25℃ or constant temperature water bath 25-35℃.