Surface anti-biofouling control of PEGylated poly(vinylidene fluoride) membranes via vapor-induced phase separation processing

This work reports the preparation of PEGylated poly(vinylidene fluoride) (PVDF) membranes by vapor-induced phase separation (VIPS). After blending PVDF with poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (Pluronic F108) triblock copolymers, solutions were exposed to water vapors in controlled conditions of relative humidity, temperature and exposure time to vapors. Chemical analysis revealed that the additive was successfully retained onto the surfaces of PVDF membranes. Compared to virgin membranes, PEGylated PVDF membranes presented improved hydrophilic properties, from a 3 wt% additive content, both at their surface (low water contact angle) and within their pores (high hydration capability). Bovine-serum-albumin, lysozyme and fibrinogen adsorption tests evidenced that non-specific protein adsorption was associated with the physicochemical nature of the membrane and the chemical nature of the protein. A 35% to 95% decrease of protein adsorption was found and best results were obtained for low molecular weight proteins, presenting less hydrophobic domains, and Pluronic content greater than 3 wt%. PEGylated brushes were efficient to prevent attachment of Staphylococcus epidermidis and Escherichia coli, from a 3 wt% additive content. Results presented highlighted that PEGylated PVDF membranes obtained by VIPS processing are potentially effective low-biofouling membranes able to resist protein adsorption, bacterial attachment and biofilm formation. (c) 2012 Elsevier B.V. All rights reserved.