Fabrication of novel anti-fouling poly(m-phenylene isophthalamide) ultrafiltration membrane modified with Pluronic F127 via coupling phase inversion and surface segregation

The novel poly(m-phenylene isophthalamide) (PMIA) ultrafiltration membrane with enhanced anti-fouling performance was successfully designed using amphiphilic block copolymer Pluronic F127 via non-solvent induced phase separation (NIPS) technique combined with induced segregation. The influences of Pluronic F127 on PMIA membrane's microstructure and properties were systematically conducted by employing a series of characterized methods. Meanwhile, the density functional theory (DFT) calculation was employed to study the intermolecular force among the bulk PMIA, Pluronic F127 additive, solvent, and inorganic agent. Results demonstrated that Pluronic F127, functioning as both a porogen and an induced-segregation additive, could effectively affect membrane structure and property. Specifically, the resultant membrane morphologies of the sublayer gradually altered from the finger-like pore to cavity-like shape, and the pore diameter and porosity displayed a stepwise upward trend via increasing the concentration of Pluronic F127, which further induced the loss of the membrane's mechanical strength. The filtration experiments demonstrated that the water permeation was enhanced, along with the slightly reduced rejection to bovine serum albumin (BSA) with the increasing concentration of Pluronic F127. Furthermore, the fouling resistance and stability were improved remarkably, which benefited from the enhanced hydrophilicity caused by the migration of polyethylene glycol (PEO) segment of Pluronic F127 toward membrane surface and inner-pore wall. Additionally, DFT calculation confirmed the interaction energy among the dope components, which provided theoretical support on the dope design. In summary, the Pluronic F127/PMIA ultrafiltration membrane demonstrated great potential in the field of water purification and wastewater reclamation.