工艺因素对溶胶-凝胶法制备SiO_2微球粒径的影响

Effect of technical parameters on microsphere size of SiO_2 prepared by sol-gel methods

采用Stber溶胶-凝胶法,在碱性体系中水解正硅酸乙酯(TEOS),制备单分散球形SiO2,研究反应时间、温度、加水量、TEOS浓度、氨水浓度对所制备SiO2粒径大小的影响。结果表明,反应时间对SiO2粒径的影响较小,随着反应时间的延长,颗粒粒径有增大趋势;随着反应温度升高以及加水量、氨水浓度和TEOS浓度增大,SiO2的粒径也增大,但持续增加水的用量,SiO2的粒径会出现变小的趋势。溶胶-凝胶法制备SiO2最佳的工艺条件为:反应时间为3h,温度为45℃,加水量为17.73mol/L,TEOS浓度为0.195mol/L,氨水浓度为0.821mol/L。

Stber sol-gel methods were employed to prepare monodispersed microsphere SiO2 by hydrolyzing TEOS in alkaline system,and the influence of reaction time,temperature,water amount,TEOS and ammonia concentrations on the microsphere size of SiO2 was investigated.The main research results obtained are as follows： Reaction time has little influence on SiO2 size,and with reaction time increasing,the particle size tends to increase as well;with the increase in reaction temperature,water amount,ammonia and TEOS concentrations,SiO2 size also increases,yet further increase in water amount will result in the diminishing size.For preparing SiO2 via sol-gel methods,the optimum technical conditions are 3 hours of reaction time,reaction temperature at 45 ℃,17.73 mol/L of water amount,0.195 mol/L of TEOS concentration,and 0.821mol/L of ammonia concentration,respectively.