Dynamically Responsive Multifunctional Asymmetric Triblock Terpolymer Membranes with Intrinsic Binding Sites for Covalent Molecule Attachment

Asymmetric ultrafiltration membranes derived from block copolymer self-assembly have seen growing attention as a result of their ordered pore structures and scalable fabrication process. One route to extend their utility is to provide, through the molecular architecture of the block copolymer, covalent binding sites for facile attachment of foreign functional molecules. Here, we report the synthesis of triblock terpolymer poly(styrene)-block-poly(4-vinylpyridine)-block-poly(propylene sulfide) (SVPS) and its fabrication into isoporous ultrafiltration membranes. Final SVPS membrane top surfaces exhibit narrowly dispersed mesopores with 6-fold symmetry. Membranes show a switchable response to pH changes demonstrating the potential as a chemical gate. Membrane pore surfaces are decorated with thiol groups providing active covalent binding sites via versatile thiol-ene click chemistry. The work may open pathways to produce high-performance multifunctional membranes for chem- and bio-sensing and for separation and as membrane reactors.