Characterization of membranes prepared from PVDF/PAN blends and their modification with hydrolysis

Abstract

In this study, the melt-spinning and stretching processes were used to prepare polyvinylidene fluoride (PVDF)/polyacrylonitrile (PAN) blend hollow-fiber membranes. These blend membranes have a higher tensile strength than those prepared via the wet phase inversion method. The influence of stretching temperature and draw ratios on the membrane microstructure, pure water flux, and porosity of the membranes was studied. The draw ratio and the stretching temperature can greatly affect the morphology and the permeation performance of the membranes. The Fourier transform infrared spectra demonstrate the differences in the PVDF/PAN blend membranes before and after hydrolysis. The water flux of the hydrolyzed PVDF/PAN blend membranes is sensitive to pH value and salt ionic strength. The effects of different salt ions on the permeability of the hydrolyzed membranes were also investigated.