▎ 摘　　要

NOVELTY - Preparing graphene polyionic liquid composite material comprises e.g. preparing graphene oxide, maintaining temperature, under stirring adding graphite powder into beaker containing concentrated sulfuric acid, adding sodium nitrite, potassium permanganate mixture, reacting, maintaining water bath, stirring, incubating, adding warm water, raising temperature, diluting using warm water, pouring, adding hydrogen peroxide, filtering using filtered product and washing using hydrochloric acid until the filtrate is free of sulfate ions and vacuum drying using oven to obtain graphene oxide. USE - The composite material is useful in biosensors and supercapacitors. ADVANTAGE - The material has good performance in adsorption and separation of contaminants. DETAILED DESCRIPTION - Preparing graphene poly ionic liquid composite material comprises (i) preparing graphene oxide: (ia) maintaining the temperature at 0-5 degrees C, under stirring condition, adding 5g 800 mesh graphite powder into 1000 ml beaker containing concentrated 115 ml sulfuric acid into 1000 ml beaker, adding 2.5 g sodium nitrite, 15 g potassium permanganate mixture, reacting for 15 minutes, maintaining water bath at 35 degrees C warm water bath, stirring and incubating for 30 minutes, adding 230 ml warm water, raising temperature to 98 degrees C for 15 minutes, diluting using warm water to 700 ml, pouring 50 ml, adding 30 wt.% hydrogen peroxide, filtering when it is hot, (ib) using filtered product and washing using 5% hydrochloric acid until the filtrate is free of sulfate ions, (ic) using step (ib) product, vacuum drying at 60 degrees C using oven to obtain graphene oxide, (id) using 25 mg dried graphite oxide powder, ultrasonic dispersing for 30 minutes in 500 ml distilled water, to prepare 0.05 mg/ml graphene oxide solution, (ie) using step (id) graphene oxide sol, centrifuging, to obtain precipitate, vacuum drying at 60 degrees C using oven to obtain graphene oxide, (ii) preparing ionic liquids 1-((2methacryloyloxy)-ethyl)imidazole-3-butyl bromide, (iia) using 500 ml three-necked flask, placing in an ice-water bath, passing high-purity nitrogen gas, weighing 39.37 g 2-bromoethanol, 33.39 g methacryloyl chloride and 31.36 g triethylamine, dissolving in 50 ml of dichloromethane, mixing slowly, adding into three-necked flask, (iib) mixing and stirring at room temperature for 18 hours, filtering, washing using deionized water for 4 times, separating using separating funnel, drying organic layer using anhydrous magnesium sulfate, vacuum filtering to obtain pale yellow liquid 2-bromoethyl methacrylate, (iic) using 250 ml single-necked flask, adding 40.46 g 2-alkyl acrylate, ethyl bromoacetate and 26.03 g butyl imidazole, adding 2,6-di-t-butyl-4-methylphenol, stirring at 40 degrees C for 24 hours, to obtain viscous yellow liquid, (iid) dissolving in 30 ml dichloromethane, precipitating with 200 ml tertiary butyl ether for 3 times, to obtain the product, (iii) preparing ionic liquid polyethylene graphene composite material, (iiia) using 0.5 g step (i) product, ultrasonic dispersing of graphene oxide in 130 ml dimethylformamide/water with ratio of 9:1, carrying out ultrasonic dispersion for 30 minutes, adding 0.3 g sodium borohydride, centrifuging at 80 degrees C for 12 hours for 4 times, washing using water, vacuum drying at 60 degrees C, to obtain partially reduced graphene oxide (iiib ) using 0.5 g of partially reduced graphene oxide, dispersing in 130 ml dimethylformamide/water with ratio of 9:1 mixed solution, carrying out ultrasonic dispersion for 1 hour, adding 2 g 1-((2-methacryloyloxy)-ethyl)imidazole-3-butyl bromide (MEBIm-Br) in 2 g azobisisobutyronitrile, reacting at 70 degrees C for 8 hours using nitrogen, washing using water for many times, centrifuging, vacuum drying at 60 degrees C for 24 hours, to obtain a powder, (iiic) using step (iiid) 0.5 g powder, ultrasonic dispersing in 100 ml distilled water, adding 10 ml 80 wt.% hydrazine hydrate, reacting at 100 degrees C for 24 hours, washing for many times using ethanol and water, centrifuging and vacuum drying at 60 degrees C for 24 hours, to obtain graphene poly ionic liquid composite material (RGO-poly-MEBIm-Br), where imidazole based ionic liquid is 1-butyl-3-methylimidazolium bromide. An INDEPENDENT CLAIM is also included for graphene poly ionic liquid composite material is prepared by above method.