混合表面活性剂体系中丰富形貌的介孔氧化硅合成探究

摘要

在非离子表面活性剂F127(EO106PO70EO106)和阳离子表面活性剂CTAB复配体系中,通过酸性介质中正硅酸乙酯(TEOS)的水解,得到了形貌均一、孔道规则的介孔氧化硅.通过对反应物F127、CTAB、HCl和TEOS浓度效应和温度效应的单因素探究,发现反应物浓度和温度的改变对产物的形貌都有很大的影响,只有在一个很窄的浓度区间且室温条件下才可以得到形貌规整的螺旋结构.在该混合表面活性剂复配体系中,CTAB起到了致孔剂的作用;而F127则起到了调控产物形貌的作用,且F127的浓度需要控制在临界胶束浓度以下一个合适的浓度范围内.对非离子型表面活性剂和阳离子型表面活性剂(两者均为非手性试剂)复配体系中得到了螺旋状介孔SiO2的反应机理进行了探讨.%A new approach was developed for regulating the morphology and mesopore structure of mesoporous materials.A variety of mesoporous silica with complex architectures have been successfully fabricated in mixed F127 (EO106PO70EO106)-CTAB systems by the hydrolysis of TEOS in aqueous HC1 solutions,such as nanofiber,gyroids,spheres and curved shells.By the investigation of the concentration effect of the reactants and the temperature effect,it has been observed that helical structures of mesoporous silica can only be obtained within a relatively narrow concentration ranges under room temperature.In these mixed systems,CTAB acts as the pore-induced agent,and F127 can tune the sample morphology only when the concentration of F127 is below the cmc.Based on the research results,detailed mechanism for the helical mesoporous silica synthesized in non ionic surfactants and cationic surfactants mixed systems were discussed innovatively.