MOF-801 incorporated PEBA mixed-matrix composite membranes for CO2 capture

Abstract

The combination of CO2-selective porous framework with polymeric material is promising for developing mixed-matrix membranes. In this work, a novel metal organic framework MOF-801 nanocrystal was introduced into polyether-block-amide (PEBA) polymer to fabricate a new mixed-matrix material for CO2 separation. A thin membrane layer consisting of MOF-801 filler and PEBA matrix was successfully formed on a porous substrate via spinning-coating approach. SEM, XRD, TGA, FTIR and adsorption test were applied to systematically characterize the as-prepared MOF-801 crystals and MOF-801/PEBA mixed-matrix composite membranes. It was found that uniform incorporation of microporous MOF-801 with preferential CO2 adsorption provided fast and selective transport channels for CO2 over N2, thereby achieving an increase both in CO2 permeance and CO2/N2 mixed-gas selectivity compared with pure PEBA membrane. The optimized MOF-801/PEBA mixed-matrix composite membrane (MOF loading of 7.5 wt%) exhibited high and stable separation performance with CO2 permeance of 22.4 GPU and CO2/N2 selectivity of 66 under mixed-gas permeation test, showing great potential for practical CO2 separation.