Preparation and characterizations of charged PVDF membranes via composite thermally induced phase separation (C-TIPS) method

The charged poly(vinylidene fluoride) (PVDF) membranes were prepared by composite thermally induced phase separation (C-TIPS) method with perfluorosulfonic acid (PFSA) as additive. The results verify that the porosity, surface hydrophilicity and pure water permeation flux ( J W ) increase with the addition of PFSA for the membranes. The highest J W of 507.2   ±   1.2   L/(M 2   H   bar) is obtained for the membrane cast at 90   °C. Much higher casting temperature isn’t advantageous to improve J W value for the PVDF membranes. All membranes exhibit negative apparent zeta potential ( ζ app ). The crystallinity in β phase increases as casting temperature increases for all PVDF membranes.