Sol-gel synthesis of SBA-15: Impact of HCl on surface chemistry
Sol-gel synthesis of SBA-15: Impact of HCl on surface chemistry
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DOI：
10.1016/j.micromeso.2018.05.043
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发表时间：
2018-11-15
影响因子：
5.2
通讯作者：
Wilson, Karen
中科院分区：
文献类型：
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作者：
Pirez, Cyril;Morin, Jean-Charles;Wilson, Karen
介孔二氧化硅的表面功能化是其作为吸附剂和催化剂载体应用的关键。在这里，我们报告了氯化物对SBA-15的物理化学性质的影响，特别是反应性羟基的表面密度。用N-2多孔仪、X-射线衍射仪、扫描电子显微镜、透射电子显微镜、傅立叶变换红外光谱和反相色谱(IGC)对样品的整体和表面性能进行了表征。在SBA-15的溶胶-凝胶制备过程中，当HCl浓度从0.1-2.0M增加到2.0M时，表面硅醇覆盖率增加了一倍，介孔从4.2 nm增加到4.9 nm。IGC显示，SBA-15的比表面能和相应的表面极性与表面硅醇的性质有关，因此在SBA-15合成过程中调节HCl浓度提供了一条容易获得亲水或疏水二氧化硅的途径，进而提供了一种控制其官能化和吸附性能的手段。
Surface functionalisation of mesoporous silicas is critical to their application as sorbents and catalyst supports. Here we report the impact of chloride on the physicochemical properties of SBA-15, notably the surface density of reactive hydroxyl groups. Bulk and surface properties were characterised by N-2 porosimetry, X-ray diffraction, SEM, TEM, FTIR spectroscopy, and Inverse gas chromatography (IGC). Increasing the HCl concentration from 0.1 -> 2.0 M during the sol-gel preparation of SBA-15 increased the surface silanol coverage two-fold, and slightly widened mesopores from 4.2 to 4.9 nm. IGC reveals that the specific surface energy and corresponding surface polarity of SBA-15 correlate with surface silanol properties, and hence tuning the HCl concentration during SBA-15 synthesis offers a facile route to hydrophilic or hydrophobic silicas, and in turn a means to control their functionalisation and sorptive properties.