The influence of Al(OH)3-coated graphene oxide on improved thermal conductivity and maintained electrical resistivity of Al2O3/epoxy composites

This study investigates the thermal and electrical conductivity of Al2O3/epoxy composites containing graphene oxide and Al(OH)(3)-coated graphene oxide. The functionalized graphene oxide was prepared by sol-gel method with aluminum isopropoxide (AlIP). The aluminumhydroxide layer (50-150 nm) was successfully formed on graphene oxide surface. The introduction of both graphene oxide and Al(OH)(3)-coated graphene oxide in Al2O3/epoxy composites significantly improved the thermal conductivity due to the high thermal conductivity of graphene-based materials and their role as heat conductive bridges among the Al2O3 particles (<10 mu m). The thermal conductivities of 80 wt% Al2O3/epoxy composites-containing 5 wt% graphene oxide and Al(OH)(3)-coated graphene oxide are 3.5 and 3.1 W/mK, respectively. On the other hand, the Al(OH) 3-coated graphene oxide/Al2O3/epoxy composites exhibited the more retained electrical resistivity compared with graphene oxide/Al2O3/epoxy composite. Thus, the Al(OH)(3)-coated graphene oxide composites showed simultaneously improvements in the thermal conductivity and retention of electrical resistivity.