Mixed Matrix Membranes for C2H4/C2H6 Separation Using a Phosphate Anion-Pillared Microporous Material

The development of efficient membranes for ethylene/ethane (C2H4/C2H6) separation is highly important. Here, we report the development of a series of new mixed matrix membranes (ZnAtzPO4/6FDA-DAM MMMs) based on a microporous material with phosphate anion pillar ZnAtzPO4 (Atz = 3-amino-1, 2, 4-triazole) and 6FDA-DAM polymer matrix. Compared with the pure 6FDA-DAM membranes, the C2H4 permeability and the C2H4/C2H6 selectivity of 10 wt % ZnAtzPO4/6FDA-DAM MMMs were simultaneously increased by 46 and 6%, breaking the trade-off between permeability and selectivity. Interestingly, the separation performance of ZnAtzPO4/6FDA-DAM MMMs at 10 wt % for the equimolar C2H4/C2H6 gas mixture was 105.0 Barrer and 3.90, which surpassed the 2013 upper bound of C2H4/C2H6. For ZnAtzPO4/6FDA-DAM MMMs with 10 wt % filler loading, both the solubility selectivity and the diffusion selectivity continued to rise concurrently, enhancing the C2H4/C2H6 separation performance of ZnAtzPO4/6FDA-DAM MMMs. This work generates a useful concept for the design and fabrication of high-performance MMMs.