Preparation and properties of rGO@Al2O3 filled thermal conductive silicon gel

The high thermal conductivity of graphene shows great potential in the thermal management of electronic systems. Spherical Al2O3 was modified by polydiallyl dimethyl ammonium chloride （PDDA） to make the surface of Al2O3 positively charged， and then combined with negatively charged graphene oxide through electrostatic assembly. After high temperature thermal reduction， rGO@Al2O3 hybrid filler was obtained， and the hybrid filler was filled into the two-component silicone rubber. The thermal silicon gel enhanced by rGO@Al2O3 was further prepared. Then， the morphology and structure of the material during the preparation process were characterized by AFM， SEM， Raman， XRD， etc.， and the thermal conductivity and mechanical properties of thermal silicon gel were tested and analyzed. The thermal conductivity of thermal silicon gel which filled with rGO@Al2O3 prepared by 2% （mass fraction）GO is 0.817 W/（m·K）. Compared with the thermal conductive silicon gel filled with pure Al2O3， the thermal conductivity of rGO@Al2O3 silicon gel has been greatly improved.