To date, polymer membranes still encounter several challenges including the trade-off effect between permeability and selectivity, low resis-tance to fouling and chemical stability. Organic-inorganic hybrid membranes can make use of the advantages of organic materials and inorganic materials. In recent years, the rapid development of nanomaterials plays an important role in promoting the development of new composite membranes. Especially, the application of two-dimensional graphene nanomaterials has attracted more and more attentions. However, graphene has high chemical stability, inert surface, weak interaction with other media, and strong van der Waals force between graphene nanosheets, which is easy to aggregate and difficult to disperse in water and solvents, seriously hindering its application in polymer membrane materials. Graphene oxide (GO) introduces a large number of oxygen-containing polar groups on its surface or edge, which alleviates the strong interaction between nanosheets. Therefore, GO demonstrates good dispersibility in water and polar solvents. A large number of oxygen-containing groups also provide rich reaction sites for preparing modified graphene. In addition, GO has the advantages of large-scale production and low cost, making GO widely used in polymer membrane materials. Popular polymer membrane materials such as polyvinylidene fluoride, polysulfone and polyethersulfone were individually blended with GO, modified GO, or composite nanomaterials to prepare mixed matrix membranes via immersion precipitation phase inversion. Because the hydrophilicity, pore structure and surface roughness were improved effectively, the mixed matrix membranes showed the enhanced permeability and antifouling property, and even presented new functions such as antibacterial. An appropriate amount of GO or modified GO was introduced into the ultrathin active layer or porous sublayer of polyamide thin-film composite membranes. The permeaselectivity, antifouling and chlorine resistance of the nanocomposite membranes were improved due to the enhanced hydrophilicity and charge property of active layer and the optimal structure of active layer. In addition, high-flux GO laminated membranes can be fabricated by layer-by-layer assembly using non-covalent bond interactions such as electrostatic, hydrogen bonding, van der Waals force, or covalent bonding between GO active sites and crosslinking agent. This review offers the research progress with respect to the application of two-dimensional graphene nanomaterials to improve the structure and properties of polymer membranes based on the methods of physical blending, interfacial polymerization and layer-by-layer assembly. In addition, the challenges and prospects of industrial applications of two-dimensional graphene-based nanomaterials in polymer membranes are prospected. © 2019, Materials Review Magazine. All right reserved.
