Fabrication of robust ZIF-8 membranes on commercial polymer supports via a dual-silane locking strategy

ZIF-8 membranes have emerged as a promising alternative to energy-intensive cryogenic distillation for propylene/propane (C 3 H 6 /C 3 H 8 ) separation. However, the stability of ZIF-8 membranes fabricated on low-cost polymer supports is often compromised by the intrinsic mismatch between the mechanical flexibility of the polymer substrate and the brittle nature of the ZIF-8 layer. Herein, we report a dual-silane locking strategy to construct dense, highly intergrown ZIF-8 membranes on commercial polysulfone supports. By engineering a silanol- and amine-functionalized interfacial layer, strong interfacial adhesion is achieved while simultaneously regulating ZIF-8 nucleation and growth, leading to continuous, crack-free membranes with tightly interpenetrated grains. The resulting membranes exhibit a C 3 H 6 permeance of 152 GPU and a C 3 H 6 /C 3 H 8 separation factor of 30.1 at 25 °C and 1 bar, maintaining stable separation performance over 108 h of continuous operation. Moreover, the membranes demonstrate excellent mechanical flexibility and resistance to deformation, underscoring their potential for scalable and industrially viable olefin/paraffin separation.