利用EDTAN%作为矿化剂,在近中性条件下于室温合成了厚壁(约3nm)蠕虫介孔分子筛.在反应物配比为n(CTAB):n(TEOS):n(EDTAN%):n(H20)=(0.05—0.2):(0.1—2):(0.1~0.5):(100~500)范围内都能得到介孔二氧化硅.以XRD、N2吸附、FTIR、SEM和TEM详细考察了体系配比和温度对介孔二氧化硅结构和形貌的影响,发现CTAB用量越大,介孔d值相应增大.温度对介孔二氧化硅的结构和形貌有很大的影响,温度在2-15℃范围内都能生成孔径分布较规则的介孔,介孔材料的形貌随温度的升高由空心管变成小颗粒聚集体;合成的介孔分子筛中的模板剂可以通过乙醇萃取的方式除去.提出了介孔的生成遵从(S^+-E^-)°I^°中性模板机理.
Using EDTANa2 as mineralization agent, mesoporous silicas with wormlike mesopores and thick pore wall( about 3 nm) were facilely synthesized at room temperature and near-neutral pH. The mesoporous silica can be obtained with reactants molar composition range of n(CTAB):n(TEOS):n(EDTANa2): n(H20) =(0.05-0.2): (0. 1-2): (0. 1-0.5): (100-500). XRD, N2 sorption, FTIR, SEM and TEM methods were carded out to investigate the topological and morphological properties of the mesoporous silicas. As the amount of CTAB increased, the d spacing value of mesoporous silica increased correspondingly. Temperature has a great effect on the synthesis of mesoporous silica. When temperature increased from 2 ℃ to 20 ℃, morphologies of the mesoporous silica varied from hollow micro-tubes to granule aggregates. Based on the experiments, a modified neutral mechanism of( S^+ -E^- )°-I° was prooosed.