微乳液法制备纳米二氧化硅粉末工艺的研究

Study on Synthesis Technology for Nano - Sized SiO_2 Powder by Microemulsion Method

采用微乳液法制备了高比表面积纳米SiO_2粉末,考察了微乳液体系的配制、反应物浓度、反应温度、焙烧温度、共沸蒸馏脱水工艺制备的纳米SiO_2性能的影响,并通过比表面积(BET)、透射电镜(TEM)、红外光谱分析(IR)、X射线衍射(XRD)对样品进行了表征。结果表明,粉末制备的工艺参数对样品性能影响较大,在较佳工艺条件下制备的纳米SiO_2粉末近似呈球形,粒径为15-30nm,比表面积高达580-630m^2/g。共沸蒸馏工艺能充分地脱去凝胶中残余的水分,防止因含水胶体干燥过程引起的粉末硬团聚,从而显著地提高了粉末的性能。

The nano-sized SiO_2 powder was with high specific surface area prepared by microemulsion method, and studied the effects the formatio of microemulsion, reactant concentration, reactant temperature, calcination temper- ature, azeotropic distillation on the properties of the powder were strdied. The powder was charaterized withBET, TEM, IR and XRD. The results show that the influence of the synthesis technology on the properties of powder. It is found that the powdery approximately of spherical grains with the size 15～35nm and the specific surface area 580～630m^2/g. The azeotropic distillation process could effectively dehydrate hydrous silica and prevent the formation of hard agglomerates durngi the evaporation.