以四乙氧基硅烷(TEOS)为原料, N,N-二甲基甲酰氨(DMF)为模板, 采用二次催化的溶胶-凝胶法制得微米级多孔性硅胶微球. 考察了一次催化水解缩聚过程中水量、乙醇量, 二次催化反应过程中电解质浓度、搅拌速度对微球粒径的影响, 并采用扫描电子显微镜(SEM)、激光粒度分布仪、比表面及孔径分析仪、显微镜-图像颗粒分析系统进行表征. 结果表明, 制得硅胶微球球形规则且无团聚现象, 平均粒径(D50)为8.9μm, 粒径呈典型高斯分布, 比表面积546.67m2/g, 孔体积0.7142m3/g, 孔径主要分布在2~8nm之间, 分布范围窄; 硅胶微球粒径大小随一次催化过程中水量、乙醇量及二次催化过程中电解质浓度增加而增大, 随乳状液形成过程中搅拌速度加快而减小.
Micrometer SiO2 microspheres were prepared by two-step catalytic Sol-Gel method with tetraethoxysilane (TEOS) as starting material and N,N-Dimethylformamide (DMF) as template. The effects of some factors on the diameter and particle size distribution of the SiO2 microspheres were discussed, such as H2O quantity and ethanol quantity during the first catalytic process, the electrolyte concentration and stirring speed during the secondary catalytic process. SiO2 microspheres were characterized by SEM, Zetasizer, BET measurements and microscope-particle image analysis system. Results show that SiO2 microspheres are mostly regular-ball with no particle agglomeration. The mean particle size (D50) is 8.9μm, and the particle size distribution follows typical Gaussian distribution. The specific surface area is 546.67m2/g, and pore volume is 0.7142m3/g, with a narrow pore size varied from 2nm to 8nm. Also the particle size increases with water quantity, ethanol quantity and NaCl concentration increaing, but decreases with stirring speed acceleration.
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