在醇氨反应体系中,根据溶液在不同反应时刻电导率和粘度的变化,结合微观形貌观察,研究单分散球形SiO2的形成过程.研究表明单分散球形SiO2的形成经历3个阶段:晶核形成期,反应初期正硅酸乙酯在氨催化下快速水解,形成大量晶核,电导率和粘度迅速增加;晶核生长期,形成的晶核经聚集不断长大发育,电导率逐渐下降,粘度不断增加;颗粒稳定期,颗粒长大后,溶液电导率和粘度不再变化,而颗粒形态不够完整,经过一定时间的稳定发育后,最终形成结构密实的单分散球形SiO2.研究还表明,快速并分离形核和以后的长大过程是形成良好单分散颗粒的关键.
参考文献
| [1] | Kolbe G .Gas Komplexchemiische Verhalten der Kieselsaure[Z].Dissertation Jena,1956. |
| [2] | Stober W;Fink A;Bohn E .Controlled growth of monodisperse silica spheres in the micron size range[J].Journal of Colloid and Interface Science,1968,26:62-69. |
| [3] | Lee K.;Harris MT.;Mccormick AV.;Look JL. .ASSESSING EXTREME MODELS OF THE STOBER SYNTHESIS USING TRANSIENTS UNDER A RANGE OF INITIAL COMPOSITION[J].Journal of Colloid and Interface Science,1997(1):78-88. |
| [4] | Bogush G H;Tracy M A;Zukoski I V .Preparation of monodisperse silica particles:control of size and mass fraction[J].Journal of NON-CRYSTALLINE SOLIDS,1988,104:95-106. |
| [5] | Brinker C J .Hydrolysis and condensation of silicates: effects on structure[J].Journal of Non-Crystalline Solids,1988,100:31-50. |
| [6] | Blaaderen A V;Geest J V;Vrij A .Monodisperse colloidal silica spheres from tetraalkoxysilanes:particle formation and growth mechanism[J].Journal of Colloid and Interface Science,1992,152:481-501. |
| [7] | Harris M T;Brunson R R;Byers C H .The base-catalyzed hydrolysis and condensation reactions of dilute and concentrated TEOS solutions[J].Journal of Non-Crystalline Solids,1990,121:379-403. |
| [8] | Chen SL.;Yang GH.;Dong P. .THE SIZE DEPENDENCE OF GROWTH RATE OF MONODISPERSE SILICA PARTICLES FROM TETRAALKOXYSILANE[J].Journal of Colloid and Interface Science,1997(2):268-272. |
| [9] | Bogush G H;Zukoski I V .Uniform silica particle precipitation:an aggregative growth model[J].Journal of Colloid and Interface Science,1991,142:19-34. |
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