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Title: Enhancing the propylene/propane separation performances of ZIF-8 membranes by post-synthetic surface polymerization
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.  more » « less
Award ID(s):
1929596
PAR ID:
10385279
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Journal of Materials Chemistry A
Volume:
10
Issue:
4
ISSN:
2050-7488
Page Range / eLocation ID:
1940 to 1947
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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