Influence of polyvinylpyrrolidone on the hydrophilic properties of polyvinylidene fluoride-based membranes

We investigated the influence of additives of high molecular polyvinylpirrolidone (PVP) of the K-90 type in molding solutions of polyvinylidene fluoride (PVDF) in dimethylformamide on the structure and transport properties of membranes. The incorporation of PVP was expectedly proven to reduce the water entrance pressure and slightly alter the contact angle of the films prepared. The subsequent treatment of membranes with sodium hypochlorite solutions led to the effective hydrophilization of the membrane surface and the 10- to 20-fold growth of the hydraulic transparency, which was found to correspond to the partial destruction of the surface layer.