pH-sensitive membranes prepared with poly(methyl methacrylate) grafted poly(vinylidene fluoride) via ultraviolet irradiation-induced atom transfer radical polymerization

Abstract

Ultraviolet (UV) irradiation induced atom transfer radical polymerization (ATRP) was performed to graft poly(methyl methacrylate) (PMMA) onto poly(vinylidene fluoride) (PVDF) and obtain copolymer (PVDF-g-PMMA). Under UV irradiation, the polymerization not only occurred at room temperature, but also achieved a 24% conversion rate after only 120 min exposure. The result of gel permeation chromatography (GPC) indicated that the molecular weight range of the copolymer was narrow, and the UV-induced ATRP was controlled. The PVDF-g-PMMA copolymer was as an additive blended with PVDF to produce a series of novel pH-sensitive microfiltration membranes. With an increase of the copolymer ratio in the membranes, the hydrophilicity of the MF membranes increased and exhibited excellent water flux. The water flux of the pure PVDF-g-PMMA MF membrane was about ten times that of a pure PVDF membrane at pH 7. The blend membranes showed an excellent sensitivity with pH.