Immobilization of TiO2 nanoparticles on PES substrate via dopamine and poly (vinyl alcohol) for long-term oil/water purification

In this paper, a facile procedure is presented to prepare a membrane with antifouling properties based on Tio2 and polyvinyl alcohol hydrophilicity and the high adhesion of dopamine. First, vapor-induced phase separation was used to prepare the PES substrate, and then TiO2 nanoparticles were anchored on the membrane surface with the assistance of dopamine and PVA. The nanoparticles were uniformly immobilized on membrane surface, significantly advancing the performance of the PES membrane. Results of contact angle measurements revealed an outstanding improvement in the surface hydrophilicity. The fabricated membranes had higher water permeation during oil/water separation and also greater oil rejection with approximately 50% improvement compared with the pristine membrane. Moreover, a FRR of 81% after fouling with oil droplets, increasing in subsequent cycles to 87%, showing a good regeneration capability during long-term performance was achieved by the modified membrane, which confirms the low fouling tendency. Stability of NPs was investigated through a cross-flow water flux, followed by weight measurements, FE-SEM and EDX analysis prior and after the flux. The results proved the stability of modifiers on the membrane surface.