Crosslinked polyethersulfone membranes for organic solvent nanofiltration in polar aprotic and halogenated solvents

Organic solvent nanofiltration is a promising and more sustainable alternative to classic separation processes in multiple industries; however, proposed materials for polymeric membranes with high solvent stability mostly utilize unique or expensive polymers, or are fabricated by complex methods. Herein, a facile method is presented to fabricate crosslinked polyethersulfone membranes with remarkable stability in halogenated and polar aprotic solvents. After preparing the membranes by the conventional non-solvent-induced phase inversion process, a multidentate aromatic amine embedded in the polysulfone underwent diazotization/dediazonization to effectively crosslink the polymer matrix. Membrane performance was easily adjusted from ultra-to nanofiltration via the polymer fraction. The performance of the crosslinked polyethersulfone nanofiltration is similar to the state-of-the-art solvent stable membranes. A weeklong filtration experiment in dimethylformamide and chloroform underlines the membranes' excellent stability. Overall, the range of solvent stability and state-of-the-art performance, combined with high accessibility and scalability, make the presented membranes an ideal platform material.