▎ 摘　　要

NOVELTY - Preparing graphene ultrafiltration membrane comprises (i) adding concentrated sulfuric acid and sodium nitrate in reaction kettle, cooling in ice bath, adding 50-100 pts. wt. crystalline flake graphite in reaction kettle, stirring, inputting hot air in reaction kettle and stirring uniformly, (ii) adding deionized water and hydrogen peroxide and 10-30 pts. wt. hydrogen chloride in reaction kettle, conveying hot gas in the reaction kettle, drying and solidifying mixed product, preparing into graphene oxide solid, (iii) crushing, injecting 20-50 pts. wt. water in kettle to dilute, adding 10-25 pts. wt. auxiliary agent and stirring uniformly, preparing into graphene colloid, (iv) placing prepared graphene colloid in reaction kettle to stir, adding 100-200 pts. wt. polyvinylidene fluoride, mixing and stirring uniformly, obtaining casting solution, and (v) adding casting solution into interior of spraying device uniformly spraying casting solution on surface of electrode plate, and drying. USE - The method is useful for preparing graphene ultrafiltration membrane. ADVANTAGE - The spraying device uniformly sprays the prepared casting liquid on the surface of the electrode plate. The outer wall of the electrode plate absorbs the casting film liquid on the outer wall of the electrode plate by the electric charge. The high-sensitive resistance in the electrode plate quickly heats the casting film liquid. After air drying, the graphene ultra-filtration film is prepared, so as to improve the working efficiency of the casting film liquid drying, and the prepared graphene has uniform thickness and high quality.