Enhanced gas separation performance of mixed matrix hollow fiber membranes containing post-functionalized S-MIL-53

Mixed matrix hollow fiber membranes (MMHFMs) filled with metal-organic frameworks (MOFs) have great potential for energy-efficient gas separation processes, but the major hurdle is polymer/MOFs interfacial defects and membrane plasticization. Herein, lab-synthesized MIL-53 was post-functionalized by aminosilane grafting and subsequently incorporated into Ultem (R) 1000 polymer matrix to fabricate high performance MMHFMs. SEM, DLS, XRD and TGA were performed to characterize silane-modified MIL-53 (S-MIL-53) and prepared MMHFMs. Moreover, the effect of MOFs loading was systematically investigated first; then gas separation performance of MMHFMs for pure and mixed gas was evaluated under different pressures. MMHFMs containing post-functionalized S-MIL-53 achieved remarkable gas permeation properties which was better than model predictions. Compared to pure HFMs, CO2 permeance of MMHFM loaded with 15% S-MIL-53 increased by 157% accompanying with 40% increase for CO2/N-2 selectivity, which outperformed the MMHFM filled with naked MIL-53. The pure and mixed gas permeation measurements with elevated feed pressure indicated that incorporation of S-MIL-53 also increased the resistance against CO2 plasticization. This work reveals that post-modified MOFs embedded in MMHFMs facilitate the improvement of gas separation performance and suppression of membrane plasticization. (C) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.