"Graphene is a one-atom thick material that can move electrons and heat. And it is able to cling to copper. Apparently by sandwiching copper between layers of graphene, the heat created by the metal is decreased by 25 percent. When attached to copper, the graphene actually changes its structure in such a way that allows the heat to move more freely through the metal, instead of being trapped in it."
Read: Thermal Properties of Graphene–Copper–Graphene Heterogeneous FilmsFrom the paper: "We demonstrated experimentally that graphene–Cu–graphene heterogeneous films reveal strongly enhanced thermal conductivity as compared to the reference Cu and annealed Cu films. Chemical vapor deposition of a single atomic plane of graphene on both sides of 9 µm thick Cu films increases their thermal conductivity by up to 24% near room temperature. Interestingly, the observed improvement of thermal properties of graphene–Cu–graphene heterofilms results primarily from the changes in Cu morphology during graphene deposition rather than from graphene’s action as an additional heat conducting channel. Enhancement of thermal properties of graphene-capped Cu films is important for thermal management of advanced electronic chips and proposed applications of graphene in the hybrid graphene–Cu interconnect hierarchies."