Green synthesis of graphene oxide polysulfone membrane using dimethyl sulfoxide as green solvent

Abstract

Membrane technology has been widely used in various industries such as medical, food, pharmaceutical, and wastewater treatment industries. It is known as a remarkable green technology owing to its low energy consumption, small footprint and easy to be scale up. However, the usage of conventional solvent has been reported to bring undesirable impacts to the environment and public health. In view of these, green solvent namely dimethyl sulfoxide (DMSO) was used along with polysulfone (PSf) polymer and graphene oxide (GO) nanomaterials to a form a new generation mixed matrix membrane (MMM). A series of membranes were fabricated through the immersion precipitation method by varying the GO concentration from 0.0 wt% to 2.0 wt% at fixed polymer and solvent weight ratio. The fabricated membrane was characterized by contact angle, porosity, and average pore size while the performance of the membrane was evaluated through the pure water flux measurement, rejection study, and flux recovery ratio. The presence of the GO in the membrane has substantially enhanced the membrane performance in terms of hydrophilicity and pure water flux associated with the hydrophilic nature of GO. The optimal membrane performance was found at 0.5 wt% of GO nanomaterials whereby it demonstrated approximately three times increment of water flux from 28.95 L/m2·hr to 76.14 L/m2·hr while maintaining a slightly better humic acid rejection which improved by 9.55% from 48.88% to 53.55% and 13.13% enhancement in membrane hydrophilicity. At the same times, it also demonstrated great antifouling properties with a high flux recovery rate up to 96.25%.