Preparation and characterization of improved hydrophilic polyethersulfone/reduced graphene oxide membrane

Abstract

Polyethersulfone (PES)/reduced graphene oxide (rGO) membrane was prepared by phase inversion method for water treatment. Graphene oxide (GO) was obtained via modified Hummer’s method and reduced to rGO where NaBH4 was chosen as a reducing agent. FTIR was used to investigate functional groups left on rGO after reduction process. The FTIR peak at 1718 cm-1, attributed to the carbonyl (C=O) group, was absent after GO was reduced. Interlayer spacing of GO and rGO were obtained using XRD. It was found that the interlayer spacing of GO was reduced from 7.87 to 3.68 Å after reduction process due to the removal of some of the functional groups from the material. The membrane cross section showed that addition rGO increase the length of finger-like pores as compared to neat PES when it is observed under SEM. It was observed that the membrane hydrophilicity is enhanced as the contact angle of PES reduced from 69.70° to 32.99° when rGO 24 hours was introduced into the polymer matrix. The highest pure water flux obtained was 174.29 L/m2h. The membranes showed significant enhancement when rGO was used in the polymer matrix.