Enhanced antifouling ability of a poly(vinylidene fluoride) membrane functionalized with a zwitterionic serine-based layer

Abstract

In this work, an antifouling poly(vinylidene fluoride) (PVDF) membrane was fabricated through covalent surface immobilization of a zwitterionic serine-based layer via facile free radical cross-linking polymerization of serine methacrylate (SerMA) on the membrane surface. The unique network structure along with the zwitterionic nature of serine was expected to endow the prepared membranes with excellent wetting and antifouling abilities. Upon modification, wettability of the membranes was improved significantly with the water contact angle decreased to as low as 32°. Protein adsorption on the membrane surface was suppressed remarkably to as low as 4.8 μg cm⁻². Filtration experiments further demonstrated that the modified membranes showed higher flux (both water and BSA solution), higher BSA rejection ratio and much better antifouling properties. These results suggest that the zwitterionic serine-based layer on the membrane surface provided an ideal barrier between the membrane substrate and the pollutants.