Polyzwitterion grafted onto PET microfiltration membrane via surface-initiated ATRP for enhanced antifouling performance

Abstract

To address the challenges of membrane fouling, we present a surface modification strategy that combines the high efficiency of surface-initiated atom transfer radical polymerization (SI-ATRP) with the excellent antifouling properties of zwitterionic polymers. A poly(St- co -VBC) macromolecular initiator was first deposited onto poly(ethylene terephthalate) (PET) microfiltration membranes, followed by the grafting of three distinct zwitterionic polymers, poly(sulfobetaine methacrylate) (PSBMA), poly(phosphorylcholine methacrylate) (PMPC), and poly(1-(3-sulfonic acid propyl)-4-vinyl pyridinium salt) (PSPV). The successful surface modification was confirmed by water contact angles (WCA) and X-ray photoelectron spectroscopy (XPS). The WCA of the three polyzwitterionic coatings were 20 ∼ 25 o , and all decreased to 0° within 5 s, indicating their rapid surface wettability. XPS analysis revealed high sulfur or phosphorus content, suggesting their high grafting densities. The modified membranes maintained stable water flux (3700–4100 L·m −2 ·h −1 ·bar −1 ), with flux recovery rates consistently above 93% and irreversible fouling rates below 6.5%. Compared to the pristine PET membrane, the polyzwitterion modified surfaces showed significantly reduced protein adsorption (≥ 83%) and bacterial adhesion (≤ 2.5%), confirming substantially enhanced antifouling performance. Among the three coatings, the antifouling efficacy followed the order: PSPV > PMPC > PSBMA. This facile and universal surface modification strategy is expected to be widely applicable in various materials and devices.

The authors' abstract, as published at the source. Progress in Organic Coatings, 2026 · DOI ↗