Sol-gel法介孔SiO2膜的制备工艺研究

以正硅酸乙酯为硅源，氨水为催化剂，研究了sol-gel法介孔SiO₂膜的制备工艺，得到了制备SiO₂溶胶的优化工艺条件。发现催化剂氨的浓度是影响SiO₂溶胶质量的关键因素，在影响SiO₂膜制备的众多因素中，溶胶pH值、溶胶浓度和成膜助剂是影响膜制备的关键因素。实验发现，在适宜的条件例如合适的pH值下，溶胶-凝胶-干燥过程具有自适应性，能够自动调节凝胶和干燥速度，从而使凝胶干燥过程中存在的收缩在很大程度上得到减少甚至避免。采用液-液排除法对优化条件下制备的SiO₂膜的孔径分布进行了表征，结果表明，在实验条件下所获得的SiO₂膜的孔径分布在8.8～14.4nm。

Preparation of mesoporous SiO2 membrane by sol-gel method

TEOS was used as the source of silicon, ammonia as the catalyst, and mesoporous SiO₂ membrane by sol-gel was prepared and the optimized technology of the preparation of SiO₂ sol was obtained. It is found that the concentration of the catalyst NH₃ is the critical factor; and among various factors which influence the preparation of SiO₂ membrane, the pH value and the concentration of sol and template agents are the critical factors. Under suitable conditions, such as proper pH, the sol-gel-dry process is self-adaptive and can adjust the speeds of gel and drying automatically. For this reason, shrinkage during the drying of gel was weakened to great extent, even avoided. A liquid-liquid displacement method was used for the characterization of SiO₂ membrane obtained under the optimizing conditions. Result shows that the pore size distribution of SiO₂ membrane is from 8.8nm to 14.4nm.