Preparation of graphene oxide–cellulose acetate nanocomposite membrane for high-flux desalination

Graphene oxide–cellulose acetate (GO–CA) nanocomposite membranes have been successfully prepared via phase inversion method. The GO sheets were firstly well dispersed in formamide, and then the solution was mixed with acetone containing CA so as to confirm the GO sheets well dispersed in the final GO–CA nanocomposite membranes. All the GO–CA nanocomposite membranes are composed of dense skin layer and sponge-like sublayer. With the increase in GO contents (from 0 to 0.01 wt%), the skin layer gradually became thinner and the pore size in the sublayer increased; meanwhile, the contact angle of GO–CA membranes decreased from 70.59° to 53.42° due to better hydrophilicity. All the membranes, except for the nanocomposite membrane containing 0.01 wt% GO, have featured pores at about 0.9 nm. The permeation rate of the membrane containing 0.005 wt% GO was 2.3 times higher than that of the CA membrane (0 wt% GO) with a little decrease (~15%) in salt retention. Compared with CA membrane, the enhanced performance of GO–CA membranes may be attributed to their enhanced structure and hydrophilicity.