Selective swelling polysulfone-block-poly(ethylene glycol)/polysulfone homopolymers blend hollow-fiber membranes for antifouling virus/protein separation

Asymmetric hollow-fiber membranes based on polysulfone-block-polyethylene glycol (PSF- b -PEG) were developed for efficient virus/protein separation. To overcome the poor spinnability and mechanical fragility of pure block copolymer fibers, PSF homopolymer was blended as a reinforcing component, enabling continuous fabrication of hollow fibers with a dense outer skin and porous substructure. Subsequent selective swelling in acetone/n-propanol transformed the skin into a nanoporous separation layer with tunable pore sizes, while simultaneously enriching PEG segments at the membrane surface. The optimized membrane exhibited a pure water permeance of ∼410 L m −2 h −1 bar −1 , a bovine serum albumin recovery >98.7%, complete retention (log reduction value, LRV = 6.7) of Phi6 bacteriophage (size = ∼86 nm), and a LRV of 3.4 for MS2 bacteriophage (size = ∼25 nm). The PEG-enriched surface imparted sustained antifouling performance over 50 h of continuous filtration and repeated fouling–cleaning cycles. This work offers a proof-of-concept scalable strategy for engineering block copolymer hollow-fiber membranes with tailored nanoporous architectures for size-dependent virus/protein separation.