Preparation and characterization of poly (vinylidene fluoride)/TiO2 hybrid membranes

Poly(vinylidene fluoride) (PVDF)/titanium dioxide (TiO₂) hybrid membranes were prepared using nano-TiO₂ as the modifier, and characterized by Transmission Electron Microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The characterization results demonstrated that nano-sized TiO₂ particles dispersed homogeneously within the PVDF matrix, contributing to more hydroxyls and smoother surfaces. Moreover, permeate flux, retention factor, porosity, contact angle and anti-fouling tests were carried out to evaluate the effect of TiO₂ concentration on the performance of PVDF membranes. Among all the prepared membranes, PVDF/TiO₂ membrane containing 10 vol.% TiO₂ exhibited the best hydrophilicity with an average pure water flux up to 237 L·m^?2·h^?1, higher than that of unmodified PVDF membranes (155 L·m^?2·h^?1). Besides, the bovine serum albumin rejection of the hybrid membrane was improved evidently from 52.3% to 70.6%, and the contact angle was significantly lowered from 83° to 60°, while the average pore size and its distribution became smaller and narrower.