▎ 摘　　要

NOVELTY - High dielectric constant low conductivity nanocomposite, is claimed. The nanocomposite mainly utilizes small size graphene to adsorb small organic molecules, and then is added to a polymer to prepare a nanocomposite with high dielectric constant and very low conductivity. The preparation of nanocomposite comprises taking 12000 mesh expanded graphite, adopting modified ultrasonic assisted Hummer's method to prepare small-sized, preferably pre-oxidizing and ultrasonically dispersing expanded graphite, oxidizing pre-oxidized graphene under ultrasound, washing and concentrating the pre-oxidized graphene; and dissolving concentrated graphene oxide with dihydroxydiphenyl ether, diaminodiphenyl sulfide, p-aminophenol, m-aminophenol or diaminonaphthalene in dimethylformamide (DMF), conjugating benzene ring-containing organic small molecule and the graphene oxide by stirring, washing the product repeatedly with DMF solvent to remove small organic molecules that were not adsorbed with graphene. USE - Used as high dielectric constant low conductivity nanocomposite. ADVANTAGE - The nanocomposite utilizes a combination of small-sized graphene and aromatic organic small molecules, and is filled in a polymer, which has a high dielectric constant of 104 orders of magnitude and a low electrical conductivity of the order of 108 . The material is simple in shape, superior in performance and advantageous for industrial production. DETAILED DESCRIPTION - High dielectric constant low conductivity nanocomposite, is claimed. The nanocomposite mainly utilizes small size graphene to adsorb small organic molecules, and then is added to a polymer to prepare a nanocomposite with high dielectric constant and very low conductivity. The preparation of nanocomposite comprises (i) taking 12000 mesh expanded graphite, adopting modified ultrasonic assisted Hummer's method to prepare small-sized, preferably pre-oxidizing and ultrasonically dispersing expanded graphite, oxidizing pre-oxidized graphene under ultrasound, washing and concentrating the pre-oxidized graphene; (ii) dissolving concentrated graphene oxide with dihydroxydiphenyl ether, diaminodiphenyl sulfide, p-aminophenol, m-aminophenol or diaminonaphthalene in dimethylformamide (DMF), conjugating the benzene ring-containing organic small molecule and the graphene oxide by stirring for 24 hours, washing the product repeatedly with DMF solvent to remove small organic molecules that were not adsorbed with graphene; (iii) mixing the obtained product with polyvinylidene fluoride (PVDF) dissolved in DMF, mechanically stirring for 2 hours, ultrasonically dispersing for 30 minutes, placing in a vacuum oven for 2 hours to discharge the dissolved gas in the solution, casting the solution in a mold of a polytetrafluoroethylene coated with a release agent, drying in an oven, and peeling the film; (iv) placing the film in a face-to-face manner and then hot pressing into a film under a hot press, removing the film while hot, and trimming the corners; and (v) assembling the film into a flat type capacitor.