Selective Defect‐Patching of Zeolite Membranes Using Chemical Liquid Deposition at Organic/Aqueous Interfaces
Selective Defect‐Patching of Zeolite Membranes Using Chemical Liquid Deposition at Organic/Aqueous Interfaces
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DOI：
10.1002/adfm.200800054
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发表时间：
2008-11
影响因子：
19
通讯作者：
Baoquan Zhang;Cong Wang;Lin Lang;Ruili Cui;X. Liu
中科院分区：
文献类型：
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作者：
Baoquan Zhang;Cong Wang;Lin Lang;Ruili Cui;X. Liu
消除可能存在的缺陷是使沸石膜在过程工业中得到普及所必不可少的。提出并发展了一种新型的逆流扩散化学液相沉积（CLD）技术用于沸石膜的选择性缺陷修补。采用十二烷基三甲氧基硅烷（DMS）作为硅烷偶联剂，在膜表面形成保护层，使得在后续的修复步骤中可以保持晶内孔的完整。通过使用正硅酸乙酯（TEOS）和（3-氯丙基）三乙氧基硅烷（3CP-TES），在有机/水界面处的共水解和共缩合在宏观、介观甚至微观缺陷上制备倍半硅氧烷/硅酸盐杂化物。使用接触角测量、傅里叶变换红外光谱和电子探针显微分析对修复前后的silicalite-1膜进行表征。进行渗透率测定以研究修复前后膜的孔径分布。发现硅倍半氧烷/硅酸盐杂化物仅沉积在缺陷的孔口处，并且修补后缺陷可以被堵塞到小于1.3nm的孔。修复后，50/50正/异丁烷-气体混合物通过膜的分离因子可以从4.4提高到35.8，CO2/N2气体混合物通过膜的分离因子可以从1提高到15左右，同时保持合成膜的三分之二CO2渗透通量。
The elimination of possible defects is indispensable in making zeolite membranes popular in process industries. A novel counter‐diffusion chemical liquid deposition (CLD) technique is proposed and developed for selective defect‐patching of zeolite membranes. Dodecyltrimethoxysilane (DMS) is employed as the silane coupling agent, forming a protective layer on the membrane surface so that intracrystalline pores can be kept intact in the subsequent reparation step. By using tetraethoxy orthosilicate (TEOS) and (3‐chloropropyl)triethoxysilane (3CP‐TES), co‐hydrolysis and co‐condensation at the organic/aqueous interface fabricate the silsesquioxane/silicate hybrid on macro‐, meso‐ and even microdefects. The silicalite‐1 membrane before and after reparation is characterized using contact‐angle measurements, Fourier transform IR spectroscopy, and electron probe microanalysis. Permporometry is conducted to study the pore‐size distribution of the membrane before and after reparation. It is found that the silsesquioxane/silicate hybrid is only deposited at the pore‐mouth of the defects, and the defects can be plugged to less than 1.3 nm pores after patching. After reparation, the separation factor of a 50/50 n/i‐butane‐gas mixture through the membrane can be increased to 35.8 from 4.4, and the separation factor of a CO2/N2 gas mixture through the membrane can be increased to around 15 from 1, while keeping the two‐thirds CO2 permeation flux of the synthesized membrane.