Massive enhancement in the thermal conductivity of polymer composites by trapping graphene at the interface of a polymer blend

Trapping graphene at the interface of a poly(ε-caprolactone) (PCL)/poly(lactic acid) (PLA) blend is achieved through the adsorption-desorption of polymer chains on the graphene surface. The resulting composite exhibits remarkably high thermal conductivity due to the graphene sheets being controlled at the interface of the polymer blend. At 0.53 vol%, when a good co-continuous structure is formed, the thermal conductivity of the graphene composite is nearly 4 times higher than that of the pure PCL/PLA blend with co-continuous structure. Moreover, the blend achieves an extremely low thermal percolation threshold (0.11 vol%), the lowest to date, because most of the graphene sheets are selectively located at the interface of the blend with co-continuous structure.