Investigation on effect of corona plasma treatment conditions on surface modification of polyethersulfone ultrafiltration membrane

Membrane surface modification is a useful technique to improve the separation performance and reduce the fouling tendency of the polymeric membranes. The main goal of this work is to modify the surface of polyethersulfone (PES) ultrafiltration (UF) membrane by corona air plasma treatment as a cold plasma technique. For this purpose, the PES UF membranes were prepared by the non-solvent-induced phase inversion method using water as non-solvent and then the surface of the prepared membranes were modified by the corona air plasma. The influence of corona input power (180, 270 and 360 W) and corona exposure time (2, 4 and 6 min) on the membrane surface properties was investigated. The modified membranes were characterized by the SEM, AFM and contact angle analysis as well as the pure water UF permeation and swelling tests. The results indicated that the surface porosity of the PES membrane enhanced by the corona surface modification. It was observed that at constant corona treatment time, the surface roughness of the membranes increased when the corona input power varied from 180 to 360 W. Furthermore, an increase in the corona power and exposure time resulted in higher hydrophilicity of the membrane surface. The pure water flux of the unmodified PES membrane and the membrane treated at 360 W for 6 min was 6.78 and 18.8 kg/m2h, respectively.

Keywords:

Surface modification , Polyethersulfone (PES) , Ultrafiltration (UF) , Corona plasma