Enhanced ethylene transport of mixed-matrix membranes by incorporating anion-pillared hybrid ultramicroporous materials via in situ growth

The separation of ethylene/ethane based on mixed-matrix membranes (MMMs) is a promising yet challenging task. In this work, high-performing GeFSIX-3-Ni/6FDA-DAM MMMs consisting of anion-pillared hybrid material GeFSIX-3-Ni (also termed ZU-36-Ni, GeFSIX = hexafluorogermanate, 3 = pyrazine) and 6FDA-DAM were synthesized via a simple in situ method, which surpasses 2013 upper bound for C2H4/C2H6 separation. Further investigations revealed that the interfacial compatibility between GeFSIX-3-Ni and 6FDA-DAM was improved with the enhancement of hydrogen bonds and the regulated small particle size (<50 nm). Both single- and mixed gas separation experiments confirmed that the separation performance of 10 wt% GEF-PI-S MMMs (GEF = GeFSIX-3-Ni, PI = 6FDA-DAM, S = in situ method) surpassed the C2H4/C2H6 upper bound in terms of C2H4 permeability (131.4 Barrer) and C2H4/C2H6 selectivity (3.80) for equimolar C2H4/C2H6 mixed gas. This work provides insights into more efficient way of obtaining defect-free MMMs with high performances for diversified separations.