Poly(vinylidene fluoride) grafted polystyrene (PVDF-g-PS) membrane based on in situ polymerization for solvent resistant nanofiltration

Abstract

A poly(vinylidene fluoride) grafted polystyrene (PVDF-g-PS) solvent resistant nanofiltration membrane (SRNF) was designed and prepared. A PVDF porous membrane was firstly prepared by phase inversion in a non-solvent bath. PS was grafted onto the PVDF porous membrane to form a PVDF-g-PS nanofiltration membrane. The influence of grafting degree and concentration of the casting solution on the morphology of the membranes was investigated by Scanning Electron Microscopy (SEM). Separation performance was evaluated by filtering three different dyes: Rose Bengal (RB), Acid Fuchsin (AF) and Bromothymol Blue (BTB) using water, ethanol and IPA as solvents. The RB retentions of the PVDF-g-PS20 membrane in water, ethanol and IPA could reach 92.3%, 91.2% and 90% respectively. The RB retentions in water, ethanol and IPA of the PVDF-g-PS20 membrane were all higher than 90%, both in aqueous and organic solvent systems. All the results showed that the graft porous membrane was very promising for SRNF.