Preparation of a novel polyvinylidene fluoride (PVDF) ultrafiltration membrane modified with reduced graphene oxide/titanium dioxide (TiO₂) nanocomposite with enhanced hydrophilicity and antifouling properties

A novel polyvinylidene fluoride (PVDF) mixed matrix ultrafiltration membrane containing reduced graphene oxide/titanium dioxide (rGO/TiO ₂) nanocomposite was prepared by phase inversion method. The synthesized rGO/TiO₂ was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy (SEM) techniques. The prepared rGO/TiO₂ blended PVDF membranes were characterized by atomic force microscopy, SEM, water contact angle, porosity, permeation measurements, and rejection tests. Due to the high hydrophilicity of the rGO/TiO₂ nanocomposite, the rGO/TiO₂/PVDF membranes were more hydrophilic and had higher pure water flux and flux recovery ratio than the bare PVDF. The blended membranes showed remarkably good properties and performance when the rGO/TiO₂ content of 0.05 wt % was added to the casting solution. The pure water flux of the 0.05 wt % rGO/TiO₂ blended membrane was increased by 54.9% compared with the bare PVDF membrane. The antifouling study of the membranes revealed that a 0.05 wt % rGO/TiO ₂ membrane had the best fouling resistance.