Improved CO2/CH4 separation performance of mixed‐matrix membrane by adding ZIF‐7‐NH2 nanocrystals. Issue 20 (31st December 2020)

• Record Type: Journal Article
• Authors: Qian, Junfeng; Wu, Tingting; Shi, Jianqun; Chang, Hao; Liu, Donghui; Pan, Yichang
• Is Part Of: Journal of applied polymer science. Volume 138:Issue 20(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-31
• Subjects: applications -- membranes -- separation techniques; Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.50424
• Languages: English
• ISSNs: 0021-8995

Abstract

Abstract: Membrane‐based technology is an attractive alternative in terms of CO2 separation. Pebax‐based membranes are regarded as potential candidates for CO2 separation due to the favorable interaction between its poly (ethylene oxide) chains with CO2 molecules and inorganic fillers. However, the separation performance for CO2 /CH4 mixture is still suffered from the moderate gas permeability and selectivity. To overcome this problem, in this work, amino‐functionalized zeolite imidazolate framework (ZIF‐7‐NH2 ) nanocrystals were used as fillers to blend with Pebax 1657 for fabricating mixed‐matrix membranes (MMMs). XRD, Brunauer–Emmett–Teller (BET), scanning electron microscope, and 1 H nuclear magnetic resonance characterization indicated that ZIF‐7‐NH2 with the highest crystallinity was synthesized. Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry (DSC), and Young's modulus showed that it has good interfacial interaction. Gas separation test results showed that both the CO2 permeability and CO2 /CH4 selectivity of the 31 wt% ZIF‐7‐NH2 /Pebax MMMs increased by 80 and 170%, respectively. The improved performance is attributed to the addition of ZIF‐7‐NH2 nanocrystals and the favorable interfacial interactions between the polymer and ZIF‐7‐NH2 nanocrystals. Furthermore, the polyvinylidene fluoride supported hollow fiber composite membranes also exhibit the long‐term stability for CO2 /CH4 separation. Abstract :