Fouling control through the hydrophilic surface modification of poly(vinylidene fluoride) membranes

Abstract

A hydrophilic fouling-resistant poly(vinyl alcohol) (PVA) based polymer was synthesized by the etherification of PVA with monochloroacetic acid under alkaline conditions, and the polymer, PVA-OCH2COONa, was subsequently applied to modify a poly(vinylidene fluoride) (PVDF) membrane to both enhance the hydrophilicity and provide fouling resistance. The successful etherification was confirmed by 13C-NMR and attenuated total reflectance-Fourier transform infrared spectroscopy, whereas the synthesized polymer was shown by differential scanning calorimetry analysis to have an improved thermal stability over PVA. The physicochemical properties of the surfaces of the modified PVDF membranes were investigated with various analytical tools, including field emission scanning electron microscopy, atomic force microscopy, and contact angle analysis. Fouling tests with bovine serum albumin showed the PVA-OCH2COONa modified PVDF membrane to have both a higher pure water flux and a retarded decline in flux over the filtration period compared with the PVA-coated PVDF membrane. This study demonstrated that the modification of PVDF membranes with PVA-OCH2COONa could be an efficient method for enhancing their fouling resistance. © 2014 Wiley Periodicals, Inc