Systematic investigation of effective parameters on formation and performance of graphene oxide separation thin film membranes

Recently-developed graphene oxide (GO) thin film membranes have attracted a great deal of attention in water-treatment processes because of their high water flux and low preparation costs. In the present work, the parameters influencing the physicochemical and the separation performance of the GO thin film membranes has been introduced and the prepared membranes were applied to separate Rhodamine-B (RhB) from aqueous solutions. The effects of various parameters including GO oxidation degree, type of polymeric support, the method of membrane preparation, surface modification of the support and the concentration of GO solution on the properties of the resulting membranes were investigated. The best GO membrane, in terms of physical properties and the separation performance, was achieved by pressure-assisted filtration of GO containing higher level of oxygenated groups on the polyethersulfone (PES) support. The physical properties of this membrane was further improved through surface modification of PES by dopamine prior to the deposition of GO thin film membrane. The best GO concentration was found to be about 50 ppm. The membrane prepared in the optimized conditions removed about 94 % of RhB from water, while its pure water flux was about 623 L.M-2.h-1.