+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: not found

      Graphene oxide membranes: controlling their transport pathways

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          This review presents and discusses the remarkable progress of GO membranes, especially the strategies and mechanisms for controlling their transport pathways in liquid separation.


          Graphene oxide (GO) nanosheets with atomic thickness and tunable physicochemical properties have been considered as promising nanobuilding blocks for fabrication of separation membranes with impressive performance. There are two kinds of molecular transport channels in laminar GO membranes, interlayer nanochannels formed by adjacent nanosheets and intrinsic defects/pores/edges of GO nanosheets. It has been demonstrated that precisely controlling the transport pathways at the angstrom level, through reduction, molecule/cation cross-linking, intercalation, physical confinement, electric field adjustment, pore creation, and defect sealing, can greatly improve the separation performance of GO membranes. Herein, we first briefly review the fabrication strategies of GO membranes and then comprehensively discuss the merits and mechanisms of controlling the transport pathways of GO membranes for liquid separation applications including static diffusion, pressure-driven filtration, and pervaporation.

          Related collections

          Most cited references190

          • Record: found
          • Abstract: found
          • Article: not found

          Measurement of the elastic properties and intrinsic strength of monolayer graphene.

          We measured the elastic properties and intrinsic breaking strength of free-standing monolayer graphene membranes by nanoindentation in an atomic force microscope. The force-displacement behavior is interpreted within a framework of nonlinear elastic stress-strain response, and yields second- and third-order elastic stiffnesses of 340 newtons per meter (N m(-1)) and -690 Nm(-1), respectively. The breaking strength is 42 N m(-1) and represents the intrinsic strength of a defect-free sheet. These quantities correspond to a Young's modulus of E = 1.0 terapascals, third-order elastic stiffness of D = -2.0 terapascals, and intrinsic strength of sigma(int) = 130 gigapascals for bulk graphite. These experiments establish graphene as the strongest material ever measured, and show that atomically perfect nanoscale materials can be mechanically tested to deformations well beyond the linear regime.
            • Record: found
            • Abstract: found
            • Article: not found

            Improved synthesis of graphene oxide.

            An improved method for the preparation of graphene oxide (GO) is described. Currently, Hummers' method (KMnO(4), NaNO(3), H(2)SO(4)) is the most common method used for preparing graphene oxide. We have found that excluding the NaNO(3), increasing the amount of KMnO(4), and performing the reaction in a 9:1 mixture of H(2)SO(4)/H(3)PO(4) improves the efficiency of the oxidation process. This improved method provides a greater amount of hydrophilic oxidized graphene material as compared to Hummers' method or Hummers' method with additional KMnO(4). Moreover, even though the GO produced by our method is more oxidized than that prepared by Hummers' method, when both are reduced in the same chamber with hydrazine, chemically converted graphene (CCG) produced from this new method is equivalent in its electrical conductivity. In contrast to Hummers' method, the new method does not generate toxic gas and the temperature is easily controlled. This improved synthesis of GO may be important for large-scale production of GO as well as the construction of devices composed of the subsequent CCG.
              • Record: found
              • Abstract: not found
              • Article: not found

              The upper bound revisited


                Author and article information

                Journal of Materials Chemistry A
                J. Mater. Chem. A
                Royal Society of Chemistry (RSC)
                August 11 2020
                : 8
                : 31
                : 15319-15340
                [1 ]School of Environment and Guangdong Key Laboratory of Environmental Pollution and Health
                [2 ]Jinan University
                [3 ]Guangzhou 511443
                [4 ]P.R. China
                [5 ]Department of Civil Engineering
                [6 ]The University of Hong Kong
                [7 ]Hong Kong 999077
                [8 ]P. R. China
                © 2020




                Comment on this article