▎ 摘　　要

NOVELTY - Preparing graphene oxide composite nanofiltration membrane by spraying method involves using nano-graphite as raw material, using modified Hummers method to prepare graphene oxide, controlling different oxidation reaction time, preparing graphene oxide nano sheet with different oxidation degree, mixing the graphene oxide nano sheet with different oxidation degree at room temperature according to proportion, ultrasonically dispersing in the benign solvent to obtain the graphene oxide dispersion liquid with concentration of 0.08-0.4 g/l-1, soaking the ultrafiltration membrane in the hydrophilic solvent at room temperature to enhance the hydrophilicity of the ultrafiltration membrane, taking out and placing in the dust-free environment, using the rubber roller to remove the liquid drop on the surface of the film, preparing the dispersion liquid of the graphene oxide modifier with the same concentration as the graphene oxide dispersion liquid. USE - Method for preparing graphene oxide composite nano-filtration membrane by spraying method. ADVANTAGE - The method enables preparing the graphene oxide composite nanofiltration membrane with low operation pressure, high desalting stability, less time consumption and better expandability in a simple and controllable manner. DETAILED DESCRIPTION - Preparing graphene oxide composite nanofiltration membrane by spraying method involves using nano-graphite as raw material, using modified Hummers method to prepare graphene oxide, controlling different oxidation reaction time, preparing graphene oxide nano sheet with different oxidation degree, mixing the graphene oxide nano sheet with different oxidation degree at room temperature according to proportion, ultrasonically dispersing in the benign solvent to obtain the graphene oxide dispersion liquid with concentration of 0.08-0.4 g/l-1, soaking the ultrafiltration membrane in the hydrophilic solvent at room temperature to enhance the hydrophilicity of the ultrafiltration membrane, taking out and placing in the dust-free environment, using the rubber roller to remove the liquid drop on the surface of the film, preparing the dispersion liquid of the graphene oxide modifier with the same concentration as the graphene oxide dispersion liquid, pouring the graphene oxide dispersion liquid and modifier dispersion respectively into two spray gun material liquid tanks, alternately spraying the two kinds of material liquid on the base film after soaking for number of times, each time alternately spraying the film drying, and then spraying for the next time, the spraying amount of the graphene oxide dispersion liquid unit area is 72-90 mg/m-2 to obtain graphene oxide composite nanofiltration membrane.