In situ polymerization of PVDF-HEMA polymers: electrospun membranes with improved flux and antifouling properties for water filtration

Abstract

In situ polymerization of poly (vinylidene fluoride) (PVDF) with hydroxyethylmethacrylate (HEMA) followed by electrospinning was employed to prepare electrospun nanofibrous membranes (ENMs), referred to as PVDF-PHEMA-ENMs. Enhanced hydrophilicity of the ENMs was observed after polymerization. A decrease in the fiber thickness resulted in a decrease in the pore size and 60% improvement in the flux. The fiber mat exhibited excellent microfiltration behavior after being coated with a surface-charged chitosan (CS) polymer, compared with its non-coated counterparts. Porosity, flux and protein adsorption studies were performed for these ENMs. A comparatively less reduced flux and better recovery ratio were observed for the PVDF-PHEMA-ENMs and CS-coated PVDF-PHEMA-ENMs due to hydrophilic pendant hydroxyl groups (from PHEMA) and/or CS groups, which can prohibit irreversible protein adsorption, on the ENM surfaces. One step method for the fabrication of electospun nanofibrous membranes (ENMs) with hydrophilic surfaces and improved flux via in situ polymerization technique is described. The developed membranes also possess enhanced antifouling properties when compared with the virgin PVDF polymer.