Surface modification of polyethersulfone ultrafiltration membranes by corona plasma-assisted coating TiO2 nanoparticles

In this work, the surface of polyethersulfone (PES) ultrafiltration membranes was modified by corona air plasma and coating TiO2 nanoparticles in order to improve the separation and antifouling properties. For this purpose, the TiO2 nanoparticles which were synthesized in a rutile phase by a microwave hydrothermal method, were coated on the surface of the corona plasma treated PES membranes which were prepared via the non-solvent-induced phase inversion method. The effects of corona treatment conditions on the morphology, surface properties and separation performance of the modified membranes were studied. The fabricated membranes were characterized by FTIR-ATR, SEM, AFM and contact angle analysis. The fouling resistance and separation performance of the membranes were also evaluated by the UF permeation tests of pure water and oil in water emulsions. The experimental results showed that the corona treatment and coating TiO2 nanoparticles led to a significant enhancement of the surface hydrophilicity, improvement of the antifouling properties and permeation fluxes for all modified membranes without significant changes in cross sectional morphology of the membranes. The modified membranes had a lower fouling tendency and long term flux stability in comparison to the untreated PES membranes. Furthermore, an increase in the corona input power and treatment time resulted in higher hydrophilicity of the membrane surface as well as much more deposition of TiO2 nanoparticles on the membrane.