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。
Abstract
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.
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