▎ 摘　　要

NOVELTY - Preparation of ultrafiltration membrane involves adding graphene oxide to pure water to obtain oxidized graphite suspension, adding nickel chloride and urea to water to obtain solution (A), slowly adding solution (A) to graphite oxide suspension, stirring, ultrasonically processing, heating, cooling, adding hydrazine solution to mixture, refluxing, filtering, washing with deionized water, vacuum drying to obtain nickel hydroxide-graphene oxide composite material, adding nickel hydroxide-graphene oxide composite material and polyvinylpyrrolidone to organic solvent, ultrasonically dispersing, slowly adding polyethersulfone, stirring to obtain homogeneous casting film solution, and leaving still for defoaming, adjusting height of the blade to make the thickness of film coating between 30-40 microns, supporting with non-woven fabric, pouring homogeneous casting film liquid to scrape the film, curing in pure water tank, taking out film and drying to test performance. USE - Preparation of ultrafiltration membrane. ADVANTAGE - The method produces ultrafiltration membrane with reduced contact angle, and improved hydrophilicity, and flux recovery rate. The ultrafiltration membrane is environmentally-friendly and has excellent synergetic effect, high flux and high retention rate. DETAILED DESCRIPTION - Preparation of ultrafiltration membrane involves adding 2 g graphite powder in 98%, preferably 96 mL concentrated sulfuric acid in an ice bath, quickly stirring, slowly dripping 6 g of 99.5% potassium permanganate solution, maintaining the temperature of mixture to below 20 degrees C, stirring at 35 degrees C under water bath for 18 hours to obtain brown paste, slowly adding 150 ml water to brown paste, stirring, adding 240 ml water to diluting and stirring, adding 5 ml of 30% hydrogen peroxide to become bright yellow color solution, stirring for 2 hours, filtering, washing with 250 ml of 10% hydrochloric acid, removing other ions with deionized water and absolute ethanol, drying to obtain graphene oxide, adding 1 g graphene oxide to pure water and making up to 500 mL to obtain 2 mg/L oxidized graphite suspension, adding 0.65 g nickel chloride and 9 g urea to 50 ml water to obtain solution (A), slowly adding solution (A) to 50 mL graphite oxide suspension, stirring, ultrasonically processing for 30 minutes, heating to 90 degrees C for 1.5 hours, cooling to room temperature, adding 0.5 mL hydrazine solution to mixture, stirring, refluxing in oil bath for 24 hours until color of the mixture changed from dark brown to black, filtering the black mixture, washing with deionized water to remove excess ammonia and other ions, vacuum drying at 80 degrees C for 8 hours to obtain nickel hydroxide-graphene oxide composite material, adding 5 g of 0-2 %mass nickel hydroxide-graphene oxide composite material and 50 g of 3-5% polyvinylpyrrolidone to 74-78% organic solvent, ultrasonically dispersing for 2 hours, slowly adding 16-19% polyethersulfone, mechanically stirring at 80 degrees C to obtain homogeneous casting film solution, and leaving still for defoaming, adjusting height of the blade to make the thickness of film coating between 30-40 microns, supporting with non-woven fabric having thickness of 100 microns, pouring homogeneous casting film liquid when running speed reaches 5 m/minute to scrape the film, curing in pure water tank at 18 degrees C, 35 degrees C, 50 degrees C and 55 degrees C in sequence, taking out the film and drying to test performance.