▎ 摘　　要

NOVELTY - Preparation of magnetic nano-silver-graphene nanocomposite material includes adding graphite powder to sulfuric acid, reacting, incubating, hot filtering, washing filter cake, drying to get graphite oxide powder, taking graphite oxide powder, centrifuging and drying precipitate to get graphene oxide; dissolving graphene oxide in ethylene glycol to get mixture; ultrasound oscillating mixture, centrifuging and drying to get magnetic-graphene oxide composites; and adding F-108 surfactant, ultrasounding, adding magnetic-graphene oxide composite, centrifuging and drying precipitate. USE - Method for preparing magnetic nano-silver-graphene nanocomposite material used for inhibiting Escherichia coli (claimed). ADVANTAGE - The material has good bactericidal effect. DETAILED DESCRIPTION - Preparation of magnetic nano-silver-graphene nanocomposite material comprises maintaining 0-5 degrees C temperature, adding 5 g 800 mesh graphite powder slowly with stirring to 115 ml concentrated sulfuric acid in 1000 ml beaker, adding to mixture of 2.5 g sodium nitrate and 15 g potassium permanganate slowly, reacting under low temperature for 15 minutes, incubating at 35 degrees C water bath for 30 minutes while stirring, adding 230 ml warm water slowly, rising temperature to 98 degrees C for 15 minutes, diluting with warm water to 700 ml, pouring 50 ml 30% hydrogen peroxide, hot filtering, washing filter cake with 5% hydrochloric acid until free of sulfate ions, drying at 60 degrees C in vacuum oven to get graphite oxide powder, taking 25 mg graphite oxide powder, ultrasonic dispersing in 500mL of distilled water for 30 minutes to get 0.05 mg/mL graphene oxide sol, centrifuging and drying precipitate at 60 degrees C in vacuum oven to get graphene oxide; dissolving 1.25 g graphene oxide in 30 ml ethylene glycol, adding to 7.2 g sodium acetate, 2.0 g polyethylene glycol (PEG) and 2.5 g iron (III) chloride hexahydrate to get mixture; ultrasound oscillating mixture for 1 hour, stirring in magnetic stirrer at 50 degrees C for 20 minutes, placing in 80 ml Teflon (RTM: PTFE)-lined autoclave, placing autoclave in oven at 200 degrees C for 6 hours, cooling autoclave to room temperature, centrifuging, washing precipitate with anhydrous ethanol and drying at 60 degrees C in vacuum oven to get magnetic-graphene oxide composites; and adding 30 mL distilled water in round-bottomed flask, adding 0.15 g F-108 surfactant, ultrasounding for 15 minutes, adding 1 mL 0.015 mol/L silver nitrate solution, ultrasounding for 15 minutes adding 30 mL 0.05 mg/mL magnetic-graphene oxide composite, ultrasounding for 30 minutes, adding 30 mL 0.3 mg/mL sodium borohydride solution, ultrasounding for 3 hours, centrifuging and drying precipitate at 60 degrees C in vacuum oven.