Enhanced performance of polyvinylidene fluoride ultrafiltration membranes by incorporating TiO2/graphene oxide

Abstract

Aiming to enhance the water flux and anti-fouling performance of poly(vinylidene fluoride) (PVDF) ultrafiltration membranes, TiO2–GO/PVDF membranes were first fabricated via blending and immersion precipitation phase inversion. Following that, TiO2–GO nanocomposites grafted with different polyethylene glycol (PEG) were employed as the additives to prepare the novel PVDF hybrid membranes. FTIR spectroscope, SEM, zeta potentiometer, and static contact angle analyzer were employed to characterize the structure and surface properties of the hybrid membranes. Ultrafiltration was used to evaluate the membrane performance. Results showed that the interaction between GO and TiO2 led to the good distribution of TiO2–GO in the polymeric membrane, which increased the polarity and porosity of the hybrid membranes, thus increasing their water flux and anti-fouling performance. The maximum flux of hybrid membranes was four times that of the neat PVDF membrane. The PEG grafted on the TiO2–GO nanocomposites did not only act as a pore-forming additive, but also improved the hydrophilicity and porosity of the hybrid membrane due to the enhancement on the distribution and surface polarity of TiO2–GO. Therefore, both the flux and anti-fouling performance of PVDF membranes containing PEG-modified TiO2–GO were significantly higher than those of membranes including unmodified TiO2–GO.