Fabrication of free-standing membranes with tunable pore structures based on the combination of electrospinning and self-assembly of block copolymers

Abstract

In this study, free-standing composite membranes with tunable pore structures are fabricated by combining electrospinning and block copolymer (BCP) self-assembly and a facile biomimetic surface modification method is employed for improvement of the interfacial interaction in the composite membranes. Firstly, polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) solution is drop-coated onto a electrospun PVA/SiO₂ fiber mat which provides mechanical reinforcement, fabricating symmetric (thickness, 17 ± 2 μm) and asymmetric (thickness, ∼5 μm) composite membranes. The pore structures in the PS-b-P2VP matrix are realized by selectively swelling the P2VP block in hot ethanol and can be tuned by adjusting swelling time and swelling temperature. Moreover, pretreating the electrospun PVA/SiO₂ fibres with adhesive polydopamine (PDA) coating improves the adherence between the BCP layer and the electrospun fibres remarkably. The results of ultrafiltration performance test show the excellent performance of the composite membrane for the immobilization and capture nanoparticles (NPs).