以EDTANa_2为矿化剂近中性条件下室温合成介孔二氧化硅

Synthesis of Mesoporous Silica at Room Temperature and Near-neutral pH with EDTANa_2 as Mineralization Agent

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.