Fabrication and characterization of a novel TiO2 nanoparticle self-assembly membrane with improved fouling resistance

A novel TiO2 nanoparticle self-assembly membrane was prepared based on ultrahigh molecular weight poly(styrene-alt-maleic anhydride)/poly(vinylidene fluoride) (SMA/PVDF) blend membrane. TiO2 nanoparticle solution was beforehand prepared via the controlled hydrolysis of titanium tetraisopropoxide. The diameter (10 nm or less) and anatase crystal structure were analyzed using transmission electron microscopy (TEM) and X-ray diffraction (XRD). The SMA/PVDF blend membranes prepared by the phase inversion method were immersed into the TiO2 nanoparticle solution for a week to produce TiO2 self-assembly membranes. The chemical compositions in membrane surface were analyzed by X-ray photoelectron spectroscopy (XPS). The membrane morphologies were measured by scanning electron microscopy (SEM). Finally, the membrane hydrophilicity, protein anti-fouling property and the molecular weight cutoff (MWCO) were characterized by water contact angle measurement, static protein absorption and filtration experiments, respectively. It is demonstrated that, in comparison to PVDF/SMA blend membrane, the permeability and anti-fouling ability of TiO2 self-assembly membranes were significantly improved.