Graphene and diamond are excellent materials for thermal conductivity.Adding graphene and diamond to the matrix material can improve the thermal conductivity of the matrix material.This paper first explored a simple and environmentally friendly process for preparing graphene through electrochemical stripping,which reduced the cost of the experiment,and then explored the arrangement of graphene and diamond-coated graphene(graphene/diamond)under electric field.Finally,by adding graphene,graphene/diamond to epoxy resin,and apply an electric field across the epoxy during the epoxy solidification,the effect of electric field on the thermal conductivity of epoxy-based graphene/diamond composites was investigated.(1)The graphite paper was peeled with different concentrations of sodium hydroxide solution and sulfuric acid solution,and the exfoliated material was ultrasonically stripped in three different dispersions of deionized water,absolute ethanol,and sodium dodecylbenzene sulfonate(SDBS).Graphene was finally prepared.By comparing the stripping rate and effect of graphite paper,it is shown that the sulfuric acid solution has higher electrochemical stripping efficiency when the concentration is same.and the effects of sulfuric acid concentration,dispersion type on the graphene phase,defect density,microstructure,and surface functional groups were investigated.When the concentration of sulfuric acid is less than 0.5 mol/L,the peeling speed is slower;when the concentration of sulfuric acid is greater than 0.5 mol/L,the peeling degree of graphite paper will decrease,the defect density will increase,and the number of layers will increase significantly;When the concentration of sulfuric acid is 0.5 mol/L and ultrasonic is used,the prepared graphene has the lowest defect density and the number of layers is about 5 layers.When sulfuric acid is used as the electrolyte,the samples contain carboxyl,carbonyl,functional groups such as hydroxyl groups,sulfuric acid concentration,and the type of solution in the ultrasonic stripping process do not affect the type of functional group.(2)Explore the deposition of graphene and graphene/diamond under an electric field.First,aluminum nitrate and sodium dodecylbenzenesulfonate were used to modify graphene in different ways.The modified graphene and unmodified graphene were dispersed in different solutions,The effects of modification methods,type of dispersion,and ultrasonic time on the stability of the graphene solution were investigated.The stability of the graphene/diamond solution was also explored.(3)An electric field was applied to the graphene/graphene/diamond stabilizing solution for electrodeposition,and the electrodeposition of graphene and graphene/diamond in different dispersions was investigated.The effect of graphene orientation was observed by field emission scanning electron microscope.The dispersion of nanodiamond on the surface of graphene was analyzed by transmission electron microscopy.A stable electric field was applied during the solidification of the epoxy resin to align the graphene and graphene/diamond in the epoxy resin.The effect of the electric field on the thermal conductivity of the epoxy resin was investigated.Studies have shown that after applying an electric field to an epoxy resin,the epoxy resin contains graphene.The application of an electric field can significantly increase the thermal conductivity of the epoxy resin.For graphene/diamond-containing epoxy resins,the thermal conductivity is significantly increased by the application of an electric field during the epoxy solidification process.In this experiment,the thermal conductivity of the epoxy resin can be increased by up to 150%. |