考察了表面活性剂存在条件下利用脲醛树脂杂化沉淀制备氧化硅微球的反应过程. 不同表面活性剂条件下所得的氧化硅微球产物各不相同. 焙烧后P123 (PEO20-PPO70-PEO20)条件的杂化微球分解成壳状氧化硅碎片, CTAB(十六烷基三甲基溴化铵)条件的氧化硅严重变形, 体积收缩到前体粒子的九分之一, 而SDBS(十二烷基苯磺酸钠)条件的产物球形貌良好的保留了下来. BET分析揭示P123和CTAB条件下的氧化硅比表面分别增加了20%和13%, 而SDBS(十二烷基苯磺酸钠)条件的产物在表面积不变的条件下孔体积和孔径减少了一半. 定量分析证明SDBS条件下氧化硅纳米粒子的杂化受到了明显抑制, 而正硅酸乙酯浸渍方式的补硅量接近一倍, 这种优化的几何结构保证了氧化硅微球产物的完整性和稳定性.

Synthesis of silica microspheres has been investigated by means of urea-formaldehyde resin hybridization in the presence of surfactants. Well dispersal and spherical hybrid microspheres are obtained in the presence of surfactants. The hybrid product from the P123 (PEO20-PPO70-PEO20) condition breaks down into shell-like debris after calcined at 600 ℃, while that of CTAB (cetyltrimethylammonium bromide) deforms severely and shrinks to the one-ninth of its precursor, however, the silica product from SDBS (sodium dodecyl benzene sulfonate) condition retains good morphology. The surface area of silica products obtained in the present of P123 and CTAB increase by 20% and 13% respectively, however, that of product remains constant with its pore volume and diameter decreased by half in the case of SDBS. Quantitative analysis showed that hybridization of silica nano-particles has been inhibited in the presence of surfactants, the amount of silica from the SDBS condition almost doubles after its impregnation in TEOS (tetraethyl orthosilicate) solution and this optimized geometry guarantees the integrity and stability of the silica microspheres.