The interface regulation strategy constructing high performance C3H6/C3H8 separation membranes via bio-based polyphenols

Mixed-matrix membranes (MMMs), which integrate processable polymer with highly selective filler, exhibit significant potential for molecular separation. However, the bottleneck in regulating interface compatibility and minimizing mass transfer resistance restricts its practical application. Herein, we present a bio-based polyphenol interfacial engineering strategy to fabricate high-performance hollow ZIF-8 (HZIF-8) based MMMs (PI@H-8) for C 3 H 6 /C 3 H 8 separation. The hydroxyl groups on tannic acid (polyphenols) etch ZIF-8 and generate HZIF-8. In addition, these hydroxyl groups also form H-bonding interactions with polyimide (PI), effectively enhancing interfacial compatibility and suppressing the formation of non-selective voids. Furthermore, the HZIF-8 provides additional mass transfer channels and reduces gas transport resistance. Ultimately, the PI@H-8(20) achieved a C 3 H 6 permeability of 99.81 Barrer and a C 3 H 6 /C 3 H 8 selectivity of 20.32, which is higher than pristine PI and MMM loading 20 wt% ZIF-8, and exceeds the Robeson upper bound. The interfacial engineering strategy presents a brand-new insight into designing advanced high-performance MMMs for gas separation.