Development of graphene oxide-cellulose acetate nanocomposite reverse osmosis membrane for seawater desalination

Abstract

Cellulose acetate (CA)/Graphene oxide (GO) nanocomposite membrane was prepared by phase inversion method. GO nanosheets were added to CA matrix with the aim of improving seawater desalination performance of asymmetric CA reverse osmosis (RO) membrane and enhancing mechanical and thermal stability. GO with grain size of 2.7 nm was synthesized through modified Hummer method and dispersed in CA matrix to prepare GO/CA nanocomposite membranes. The membranes were fabricated by casting of GO/CA onto a polyester fabric. The results showed that the GO concentrations would affect the morphology, hydrophilicity, porosity, roughness, mechanical strength and thermal stability of membranes. Incorporation of GO into the CA matrix changed the porosity structure from finger-like to sponge-like. Hydrophilicity nature, storage modulus and thermal stability of CA membranes were greatly improved with incorporation of 1 wt% GO. In addition, synthetic seawater salt rejection of CA membrane modified with 1 wt% GO at 25 bar was 1.8 times higher than that of pristine CA membrane, while flux of CA membrane exhibited small reduction with the presence of 1 wt% GO.