Synergistic contribution of sulfonated poly(ether sulfone) and iminodiacetic acid functionalized-graphene oxide nanosheets towards enhancing cationic dye wastewater purification using nanocomposite membranes

Abstract

Water purification and wastewater treatment can be achieved using membrane technologies. However, conventional poly(ether sulfone) (PES) membranes suffer from hydrophobicity, fouling issues, and insufficient dye removal. In this study, hydrophilic sulfonated PES (sPES) and iminodiacetic acid-functionalized graphene oxide (IDA-GO) nanosheets were incorporated into the PES membranes to enhance cationic dye removal efficiency. PES/sPES membranes containing 0.05–0.2 wt% IDA-GO nanosheets were fabricated via phase inversion. PES/sPES@IDA-GO membrane and IDA-GO nanosheets were fully characterized using various analytical techniques. With a negative surface charge, the PES/sPES@IDA-GO membrane is a good candidate to remove cationic days. Compared with pristine PES membranes, hydrophilic nanosheets improve membrane porosity, hydrophilicity, and mechanical properties. Further altering the membrane structure by incorporating IDA-GO nanosheets into the PES/sPES-based casting solution increased the porosity and mean pore radius. Using PES/sPES@IDA-GO membrane containing IDA-GO nanosheets as low as 0.1 wt%, values of 99.9 % 19.4 L/m2.h were achieved for dye rejection and pure water flux, respectively. Tuning membrane properties using sPES and IDA-GO nanosheets enabled exceptional cationic dye removal. This offers a facile approach to engineering high-performance PES membranes for effective wastewater purification and environmental remediation applications.