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首页> 外文会议>International Zeolite Conference pt.A; 20040425-30; Cape Town(ZA) >HIERARCHICALLY ORDERED POROUS SILICA COMPOSITES: ORDERING ON THREE DIFFERENT LENGTHS WITH THREE DIMENSIONAL PORE INTER-CONNECTIVITY
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HIERARCHICALLY ORDERED POROUS SILICA COMPOSITES: ORDERING ON THREE DIFFERENT LENGTHS WITH THREE DIMENSIONAL PORE INTER-CONNECTIVITY

机译：分级排列的多孔二氧化硅复合材料：按三个不同的孔互连尺寸排列三个不同的长度

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摘要

A room temperature synthesis of hierarchically ordered porous silica is reported using colloidal spheres and a tri-block co-polymer surfactant as templates. Macropore size and ordering were controlled using a close-packed monolith of polystyrene latex spheres whereas mesoscale ordering was controlled using a surfactant containing different EO-PO-EO groups (F127: EO_(108)PO_(70)EO_(108) or P123: EO_(20)PO_(70)EO_(20)) in the presence of a co-surfactant (n-butanol or n-pentanol). The thickness and pore interconnectivity of macropores was controlled either using a silica gel containing such surfactants or using a colloidal suspension of silica or zeolite nano particles as building units. Macrospheres with interconnected windows (70-130nm) are formed when surfactant containing silica gel was used as building units whereas hollow silica macrospheres without interconnecting windows are formed when nano particles were used as building units. XRD, TEM and N_2 adsorption results suggest the presence of mesopores. Nitrogen adsorption results indicate the presence of micropores ( < 2nm) in the mesoporous walls. The mesopores are interconnected with macropores and micropores. The surface area of such materials was improved when the polystyrene latex template was removed by solvent extraction before calcination at a specific temperature. The probable mechanism of formation of such hierarchically ordered porous silica is presented.
机译：据报道，使用胶体球和三嵌段共聚物表面活性剂作为模板，室温合成了有序排列的多孔二氧化硅。大孔尺寸和有序性是使用紧密堆积的聚苯乙烯胶乳球体整体控制的，而中尺度有序性是使用包含不同EO-PO-EO基团的表面活性剂控制的（F127：EO_（108）PO_（70）EO_（108）或P123：在辅助表面活性剂（正丁醇或正戊醇）存在下的EO_（20）PO_（70）EO_（20））。大孔的厚度和孔的互连性是通过使用含有此类表面活性剂的硅胶或使用二氧化硅或沸石纳米颗粒的胶体悬浮液作为构建单元来控制的。当将含有表面活性剂的硅胶用作构建单元时，形成具有互连窗口（70-130nm）的大球，而当将纳米颗粒用作构建单元时，形成不具有互连窗口的中空二氧化硅大球。 XRD，TEM和N_2吸附结果表明存在中孔。氮吸附结果表明在中孔壁中存在微孔（<2nm）。中孔与大孔和微孔相互连接。当在特定温度下煅烧之前通过溶剂萃取除去聚苯乙烯胶乳模板时，此类材料的表面积得以改善。提出了形成这种有序排列的多孔二氧化硅的可能机理。

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