Enhancing the propylene/propane separation performances of ZIF-8 membranes by post-synthetic surface polymerization
Enhancing the propylene/propane separation performances of ZIF-8 membranes by post-synthetic surface polymerization
复制标题
通过后合成表面聚合增强 ZIF-8 膜的丙烯/丙烷分离性能
DOI：
10.1039/d1ta08705c
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发表时间：
2022
影响因子：
11.9
通讯作者：
Jeong, Hae-Kwon
中科院分区：
文献类型：
--
作者：
Park, Sunghwan;Cho, Kie Yong;Jeong, Hae-Kwon
沸石-咪唑骨架-8（ZIF-8）膜显示出优异的丙烯/丙烷分离性能。然而，它们的商业应用受到一些挑战的阻碍。一个这样的挑战是管理微结构缺陷的困难（即，晶界缺陷），导致膜性能差，并最终导致再现性问题。在此，我们介绍了一种新的有效的策略，使用合成后表面聚合来密封多晶ZIF-8膜的微观结构缺陷，该策略包括两个步骤：（1）通过合成后配体交换在膜表面上引入引发剂配体和（2）通过原子转移自由基聚合原位聚合聚（甲基丙烯酸甲酯）（PMMA）。ZIF-8膜完全覆盖有厚度小于10 nm的超薄PMMA层，将丙烯/丙烷分离因子从1060增加到1060，丙烯渗透率意外增加，有效地改善了膜的再现性。PMMA涂覆的ZIF-8膜的增强的分离性能归因于超薄PMMA层以及PMMA层中的Cu离子可能促进丙烯运输。
Zeolitic-imidazole framework-8 (ZIF-8) membranes have shown exceptional propylene/propane separation performances. Their commercial applications have, however, been impeded by several challenges. One such challenge is the difficulty of managing microstructural defects (i.e., grain boundary defects) in a consistent manner, leading to poor membrane performances and ultimately to a reproducibility issue. Herein, we introduce a new effective strategy to seal the microstructural defects of polycrystalline ZIF-8 membranes using post-synthetic surface polymerization which consists of two steps: (1) introduction of initiator ligands on the membrane surface by post-synthetic ligand exchange and (2) in situ polymerization of poly(methyl methacrylate) (PMMA) via atom transfer radical polymerization. The ZIF-8 membranes were fully covered with ultra-thin PMMA layers of sub-10 nm thickness, increasing the propylene/propane separation factor from ∼60 to ∼106 with unexpectedly increased propylene permeance, effectively improving the membrane reproducibility. The enhanced separation properties of the PMMA-coated ZIF-8 membranes were attributed to the ultra-thin PMMA layers as well as to the possible facilitated propylene transport by Cu ions in the PMMA layers.