Development of low-fouling PVDF membranes blended with poly(2-methoxyethyl acrylate) via NIPS process

Abstract

PVDF-based membranes with low-fouling and high permeability properties were developed by blending poly(vinylidene fluoride) (PVDF) with poly(2-methoxyethyl acrylate) (PMEA), a low-fouling polymer, via non-solvent induced phase separation (NIPS). Since PMEA suppresses protein adsorption and is insoluble in water, the PMEA homopolymer was used as an additive. Consequently, transparent dope solutions containing 15 wt% PVDF and 0–7 wt% PMEA were prepared using N-methyl-2-pyrrolidone as the solvent. The macrovoids in the blended membranes were larger than those in the pristine PVDF membrane and were probably attributed to the PMEA-promoted solvent exchange during the NIPS process. As a result, the pure water permeabilities of the blended membranes were 5–10 times higher than those of the pristine PVDF membrane. The ATR FT-IR characterization revealed that the PMEA composition of the membrane surfaces increased as the PMEA blend ratio in the dope solution increased. This resulted in the improvement of their low-fouling properties when used in 1000 ppm of bovine serum albumin (BSA) and lysozyme aqueous solutions. Additionally, the PMEA-blended PVDF membrane with the highest PMEA ratio showed the best low-fouling properties.