▎ 摘　　要

NOVELTY - Preparation of polyamide membrane with nanostructured coating, involves: (1) preparing dispersion of graphene oxide (GO) in 0.1-2 g/l absolute ethyl alcohol (99.5 wt.% concentration); (2) applying the formed dispersion on reverse osmosis membranes made of a selective polyamide (PA) layer, by spin-coating technique with low rotation stage, followed by high rotation; (3) repeating step (2) 1- 5 times; and (4) immersing the membranes in water, immediately after step (3). USE - Method is used for preparing polyamide membrane used in desalination of water from surface hydric body such as river, spring, bay, lagoon, sea, etc., or in processing water for industrial reuse (claimed). ADVANTAGE - The method enables preparing polyamide membrane with nanostructured coating suitable for use in effluent treatment, to increase the hydraulic permeability, compared to reverse osmosis membranes, and enable operation at low pressures and in the presence of free chlorine, thus minimizing the formation of biofilm, energy expenditure and inorganic fouling, and consequently increasing the performance of the process and the lifetime of the membranes, with reduction in operational expenses. During the method, the interface phenomena provided by a set of materials containing ethyl alcohol in high concentration, and the morphological characteristics and customized surface chemistry of GO, among other conditions, allow a differentiated technology, to obtain effective coating of GO on PA membrane. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for polyamide membrane with nanostructured coating, which comprises graphene oxide on polyamide surface. The membrane has: i) degree of oxidation greater than 35 wt.%; ii) layer distribution up to 10 nanosheets and average lateral dimension greater than 1 μm; iii) membrane permeability greater than 3.5 l/hour.m2.bar; iv) saline rejection greater than 96%; and v) preservation of oxygenates groups and groups related to polyamide after exposure, 1000 ppm/hour chlorine.