Separation of graphene oxides of different sizes by multi-layer dialysis and anti-friction and lubrication performance

Abstract

Abstract As a 2D carbon material, graphene exhibits a unique structure and outstanding properties and has been widely applied in various fields. Because the properties of graphene are closely related to their structural parameters, graphene with different size distributions is suitable for different applications. However, current methods of fine-scale separation of graphene and its derivatives have certain limitations. In this study, graphene oxide (GO) size separation using multilayer dialysis was proposed. Multiple size separation in one step was achieved by customizing the dialysis size of each layer according to the actual requirements. In this way, GOs of different sizes were separated and large-scale synthesis can be achieved using this method. Meanwhile, the anti-friction and lubrication properties of aqueous dispersion solutions of GOs of different sizes were investigated. The results indicated significant improvements of the anti-friction and lubrication properties of GO samples prepared by the proposed method, as large-scale GOs can act as lubricants by relieving, if not preventing, friction between the two friction surfaces.