Preparation and characterization of silicalite-1 membrane by counter-diffusion secondary growth
Preparation and characterization of silicalite-1 membrane by counter-diffusion secondary growth
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DOI：
10.1016/j.memsci.2009.08.040
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发表时间：
2009-12
影响因子：
9.5
通讯作者：
W. Xiao;Jianhua Yang;Jinming Lu;Jinqu Wang
中科院分区：
文献类型：
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作者：
W. Xiao;Jianhua Yang;Jinming Lu;Jinqu Wang
采用逆向扩散二次生长法（CDSG）在大孔α-Al 2 O3载体外表面制备了高性能的silicalite-1膜。与传统的硅源（正硅酸乙酯）和模板剂（四丙基溴化铵）混合形成合成溶液的方法不同，该方法从支撑壁的相反方向引入硅源和模板剂，得到了良好的膜结构和性能，并降低了化学品消耗。优化了种子粒径与载体孔径的相关性，并考察了种子粒径对膜形貌和渗透性能的影响。结果表明，所制备的膜为典型的silicalite-1膜，不含其它相。所得膜致密、连续，无明显缺陷，具有良好的渗透性能。在298 K和0.1MPa压降下，该膜的H2渗透率和H2/SF6理想选择透过率分别达到7.5×10 - 7 molm-2s-1 Pa-1和103。此外，通过CDSG方法可以大大减少模板的消耗。
High performance silicalite-1 membranes on outer surface of macroprous α-Al2O3supports were synthesized by counter-diffusion secondary growth (CDSG). Different from the conventional synthesis methods by which the silica source (tetraethyl orthosilicate) and the template agent (tetra-propyl ammonium bromide) were mixed together to form the synthesis solution, this method introduced silica source and template agent from the opposite direction of a support wall, resulting in good membrane structures and properties as well as reduced chemical consumption. The correlation between particle size of seeds and the pore size of supports was optimized, and its influence on the morphology and permeation property of the as-prepared membranes was also investigated. Results showed the as-prepared membranes were typical silicalite-1 membranes without any other phase. The membranes were dense, continuous without obvious defects, displaying good permeation property. The H2permeance and H2/SF6ideal permselectivity for the membrane prepared under optimized parameters were up to 7.5×10−7molm−2s−1Pa−1and 103 at 298K under 0.1MPa pressure drop, respectively. Moreover, by the CDSG method the consumption of the template can be greatly reduced.