Metal-induced ordered microporous polymers for fabricating large-area gas separation membranes

Metal-induced ordered microporous polymers (MMPs), a class of porous polymer, are synthesized from amine-bearing polymers, small organic linkers and divalent metal ions using a polymer-directed chemical synthesis process. Specifically, small organic linkers first coordinate to metal ions, with the resulting unit cells then self-assembling along the extension of polymer chains to construct three-dimensional frameworks. The MMPs demonstrate good controllability of crystal and framework size, as well as hydrolytic stability. MMP dispersions were coated on a modified polysulfone substrate to fabricate MMP/mPSf membranes with an ultrathin selective layer (below 50 nm) and surface areas of >100 cm². The MMPs are readily fabricated into defect-free thin selective-layered membranes with high CO₂ permeance (3,000 GPU) and stable CO₂/N₂ selectivity (78) under both humid and dry gas feed conditions, demonstrating promising CO₂ membrane separation performance. This synthetic methodology could be extended to other polymers, potentially enabling facile synthesis of membrane materials.