微乳液中四氯化硅水解制备二氧化硅微球

摘要

Microemulsion system was prepared through cationic surfactant cetyltrimethyl ammonium bromide and nonionic surfactant polyoxyethylene octyl phenyl ether(TritonX-100).Then silica microspheres with particle sizes of 45 nm and 60～ 90 nm were prepared respectively,by silicon tetrachloride,a by-product of industrial monocrystalline silicon production.The factors,such as the amount of water,ammonia concentration,SiCl4 amount,stirring rate,and temperature affecting on the microsphere particle size and surface topography of silica were investigated.The results showed that the particle size decreased with the increase of water content in CTAB W/O microemulsion,increased with the amount of SiCl4 gas,and only in the alkaline condition to get the silicon ball.In a TritonX-100 W/O microemulsion,the particle size decreased and then increased with increasing water content.The amount of SiCl4 added had little effect on the particle size.The higher the basicity,the better the sphericity and dispersion properties.Microemulsion reaction process should not be stirred and the reaction temperature should not be higher than the boiling point of SiCl4.%利用阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)和非离子表面活性剂聚乙二醇辛基苯基醚(TritonX-100)配制微乳体系,并利用工业生产单晶硅副产物四氯化硅制备粒径分别为45 nm和60～120 nm的二氧化硅微球.探讨了加水量、氨水浓度、四氯化硅用量、搅拌转速、反应温度对微球粒径及表面形貌的影响.研究表明,在CTAB乳液体系中,微球粒径随含水量的增加而减小,随通入四氯化硅气体量的增加而增大,且只有在碱性条件下才能得到硅球;在TritonX-1 00乳液体系中,微球粒径随含水量的增加呈现先减小后增大的趋势,随四氯化硅液体加入量的影响较小,碱性越高颗粒成球度越好、分散性能越好.微乳液反应过程不宜搅拌,且反应温度不易高于四氯化硅沸点.