非担载的介孔氧化硅分子筛膜的制备研究

Study on preparation of free-standing mesoporous silica molecular sieves membrane

以阳离子表面活性剂为结构导向剂,以正硅酸乙脂为硅源,于酸性条件下,在气/液界面上制备出了非担载的介孔SiO2无机膜.通过XRD,SEM以及TGA对膜进行表征,并详细考察了物料组成对膜制备的影响.研究结果表明,溶液的酸度及表面活性剂的用量对成膜的影响较大,另外,搅拌强度对膜的组成结构也有较大的影响.SEM测试表明膜的上表面光滑,下表面较粗糙,证明膜的生长是从表面开始向溶液里生长的.膜的平均厚度约为20μm.TGA曲线分析表明介孔SiO膜的热失重分3个阶段,总失重率为65%.

The free-standing mesoporous silica membranes were synthesized at air-water surface using the surfactant of cetyltrimethyl ammonium bromide （CTAB） as the template and tetraethylorthosilicate （TEOS） as the silicon. Influences of the reactant compositions and intensity of stirring on the membrane were investigated through XRD. The average thickness of the silica membrane was about 20μm. The free-standing silica membrane was intact and not easy cracked. The TGA experiment proved that the removal of the surfactant was a stepwise mechanism.