Increasing and enhancing the performance and antifouling characteristics of PES membranes using acrylic acid and microwave-modified chitosan

Abstract

The aim of this study was to coat and change the surface properties of the PES membranes to increase the membrane performance. Accordingly, we coated a layer of chitosan on a PES membrane and then modified the created layer by acrylic acid and microwave irradiation for the first time. The fabricated layer was modified by acrylic acid (AA) as a grafting agent using a household microwave apparatus without any initiator. Different concentrations of AA and irradiation power as well as irradiation times were studied for the purpose. The obtained membranes were characterized using SEM, AFM, ATR-FTIR, contact angle, cross flow filtration, and anti-fouling property measurements. SEM images showed both the formation of a chitosan-coated PES membrane under the procedure and the resultant alterations in the surface structure. Based on the results, a moderate concentration of AA could enhance the coated layer properties and the rejection capability as well as the antifouling properties of the obtained membranes. AFM images represented the changes in the nanostructure of the coated layers as well as the surface characteristics. Accordingly, the mean surface pore sizes of the obtained membranes were reduced down to 35 nm after modification calculated by SPM-DME software. The antifouling properties of the modified membranes using bovine serum albumin (BSA) as a protein pattern showed that the flux recovery ratio (FRR) of some membranes increased by three times more than that of the unmodified membrane.