Antifouling properties of Cu(tpa)@GO/PES composite membranes and selective dye rejection

Two nanocomposite types of Cu(tpa) MOFs supported on graphene oxide (Cu(tpa)@GO) were prepared by varying the ratio of MOF to GO. These composites were used to produce a series of Cu(tpa)@GO polyethersulfone (PES) composite membranes through a phase inversion method. The nanocomposites and the membranes were all characterized using a variety of physicochemical techniques such as contact angle, SEM, TEM, etc. The composite membranes exhibited high hydrophilicity and increased pure water flux relative to pristine PES and GO/PES membranes. Furthermore, the Cu(tpa)@GO/PES composite membranes presented high antifouling properties with almost 98% of flux recovery ratio compared to 43% and 78% obtained for pristine PES and GO/PES membrane respectively. Finally, these Cu(tpa)@GO/PES membranes exhibited selective anionic dye rejection of > 80% and > 50% for Congo Red and Methyl Orange respectively as compared to that observed for the cationic dye Methylene Blue at < 20%. This facile, cost-effective modification strategy offers additional criteria to design ultrafiltration membranes with selective rejection, improved fouling properties as well as increased flux for water treatment applications.