▎ 摘　　要

NOVELTY - Preparing graphene/polydopamine modified mesoporous silicon dioxide nanosheet composite high thermal conductivity film comprises (i) preparing mesoporous silicon dioxide nanosheet by taking hexadecyl trimethyl ammonium bromide and water, heating, adding cyclohexane and aqueous ammonia, dripping tetraethoxysilane and 3-aminopropyltriethoxysilane, and drying product to obtain aminopropyl-functionalized mesoporous silicon dioxide nanosheets, (ii) preparing polydopamine-modified mesoporous silicon dioxide nanosheets by dispersing mesoporous silicon dioxide nanosheet in tris(hydroxymethyl)aminomethane buffer solution, and adding dopamine hydrochloride aqueous solution to silicon dioxide nanosheet dispersion liquid, (iii) preparing graphene nanosheets by adding sulfuric acid, ammonium persulfate and natural graphite, dripping hydrogen peroxide, adding nitrogen-methylpyrrolidone, and treating, and (iv) compounding graphene/polydopamine-modified mesoporous silicon dioxide nanosheets. USE - The method is useful for preparing graphene/polydopamine modified mesoporous silicon dioxide nanosheet composite high thermal conductivity film. ADVANTAGE - The method: utilizes graphene as the main material, polydopamine-modified mesoporous silica nanosheets as auxiliary additives, and chelating effect of polydopamine surface functional groups on graphene surface functional groups during the process of assembling the film; adheres polydopamine-modified mesoporous silicon dioxide nanosheets to the graphene nanosheets; filled the folds, and gaps of the graphene sheets; and makes more uniform and flat distribution of the film, so as to make the film have high thermal conductivity. DETAILED DESCRIPTION - Preparing graphene/polydopamine modified mesoporous silicon dioxide nanosheet composite high thermal conductivity film comprises (i) preparing mesoporous silicon dioxide nanosheet by taking specific amount of hexadecyl trimethyl ammonium bromide, placing in three-neck round-bottomed flask, adding specific amount of water, magnetically heating and stirring at a specific temperature for dissolving, cooling to room temperature, adding specific amount of cyclohexane and aqueous ammonia, continuously and vigorously stirring, dripping specific amount of tetraethoxysilane and 3-aminopropyltriethoxysilane, vigorously stirring and reacting at room temperature, centrifuging and collecting the prepared product, washing for multiple times with ethanol and ethanol/acetic acid mixture respectively, drying the product after centrifugation to obtain aminopropyl-functionalized mesoporous silicon dioxide nanosheets, and storing at room temperature, (ii) preparing polydopamine-modified mesoporous silicon dioxide nanosheets by dispersing specific amount of above-mentioned mesoporous silicon dioxide nanosheet in a specific amount of tris(hydroxymethyl)aminomethane buffer solution, magnetically stirring, adding a specific amount of dopamine hydrochloride aqueous solution into silicon dioxide nanosheet dispersion liquid, stirring at a specific temperature, and centrifuging and washing to obtain polydopamine-modified mesoporous silicon dioxide nanosheets, (iii) preparing graphene nanosheets by adding a specific amount of sulfuric acid, ammonium persulfate and natural graphite in a beaker, dripping specific amount of hydrogen peroxide after stirring, allowing to stand at room temperature to obtain fully expanded graphene aggregates, washing graphene aggregates to neutrality, then adding to a specific amount of nitrogen-methylpyrrolidone, using cell crusher for ultrasonically treating for a specific period of time, centrifuging with a centrifuge, and leaving the upper layer to obtain a stable graphene dispersion liquid, (iv) compounding graphene/polydopamine-modified mesoporous silicon dioxide nanosheets, pouring specific amount of water into flask, adding specific amount of graphene dispersion liquid, then using ultrasonic instrument for uniformly dispersing, dispersing a specific amount of polydopamine-modified mesoporous silicon dioxide nanosheets in a specific amount of water, and then adding polydopamine-modified mesoporous silicon dioxide nanosheet dispersion liquid in graphene dispersion liquid under the condition of rapid stirring, where the obtained product is a composite dispersion liquid of graphene/polydopamine-modified mesoporous silicon dioxide nanosheets, and (v) preparing graphene/polydopamine-modified mesoporous silicon dioxide nanosheet composite film by diluting specific amount of graphene/polydopamine-modified mesoporous silicon dioxide nanosheet composite dispersion liquid into deionized water, then uniformly dispersing with an ultrasonic instrument, using a mixed fiber microporous filter film for vacuum filtration, adding an equal volume of deionized water for washing once before ending, filtering, where a composite film appears on filtering film, using tweezers to lightly remove composite film from the surface of filtering film, and drying in an oven to obtain the finished product. An INDEPENDENT CLAIM is also included for a graphene/polydopamine modified mesoporous silicon dioxide nanosheet composite high thermal conductivity film prepared by the above-mentioned method.