A covalently integrated ZIF-8/polyamide acid mixed matrix membrane with superior gas separation performance
Authors: Guozhen Li, Shiqi Ling, Yuhui Cui, Shilong Dong, Tianyin Liu, Ting Li, Siyu Pang, Peiyong Qin
Zeolitic imidazolate framework-8 (ZIF-8) is a typical filler used to fabricate mixed matrix membranes (MMMs) on account of its attractive advantage of high selective permeability for gas separation. However, the performance is usually affected by filler aggregation due to strong interactions among fillers and weak interactions between the polymer and fillers, which will lead to a decrease of selectivity and the performance of gas separation will be strongly influenced. Herein, we modified ZIF-8 with 3-amino-1,2,4-triazole to obtain ZIF-8-NH2, Kapton polyamide acid was selected as the polymer matrix. Results showed that the ZIF-8-NH2/Kapton MMMs has a good compatibility interface between ZIF-8 and Kapton because of the covalent bridging, even the filler loading up to 45% (mass). The 45% (mass) of ZIF-8-NH2/Kapton membrane showed 297 barrer (1 barrer = 10^-10 cm3Β·cmΒ·cm^-2Β·s^-1Β·cmHg^-1, 1 cmHg = 1333.22 Pa, standard temperature and pressure) of the permeability of H2 and 43.9 and 62.2 of selectivities for H2/N2 and for H2/CH4, respectively, which are beyond the upper limit of Robeson 2008.
