▎ 摘　　要

NOVELTY - A water separation membrane is created by depositing a set of graphene oxide (GO) nanosheets via a layer-by-layer assembly and bonding the set of GO nanosheets with each other and with a support substrate. USE - Creating a water separation membrane for water purification, areas, on-site treatment of hydrofracking flowback water, renewable energy production, and drug delivery and artificial organ development. ADVANTAGE - Water permeability of the GO membrane is one order of magnitude higher than that of a commercial forward osmosis (FO) membrane, corresponding to water flowing in the GO channel at a speed of two orders of magnitude higher than that predicted by the Poiseuille equation. The dominant path for water and solute transport is most likely formed by the clear space ( approximately 1 nm) between layered GO nanosheets. Although the GO membrane may hydrate in solutions of high ionic strength, the GO membrane retains a tight structure and exhibits high rejection and slow diffusion of solutes in solutions of low ionic strength. The GO membrane uses graphite as an inexpensive raw material, significantly lowering membrane fabrication cost. The synthesis procedure for both GO nanosheets and GO membrane is simple and scalable, providing technical readiness for scaling up the membrane production. The synthesized GO membrane has very high rejection of an organic dye with a molecular weight of approximately 500 Daltons. Water flux of the GO membrane is 4-10 times higher than that of most currently commercially available nanofiltration membranes. The facile synthesis of the GO membrane exploiting the ideal properties of inexpensive GO materials offers a myriad of opportunities to modify its physicochemical properties, potentially making the GO membrane a next-generation, cost-effective, and sustainable alternative to the long-existing thin-film composite polyamide membranes for water separation applications. DESCRIPTION OF DRAWING(S) - The drawing shows a chemical structure of the graphene oxide (GO).