To prevent overheating in devices ranging from regular smartphones to electric motors, heat sinks are usually used, distributing heat and accelerating its dissipation into the environment. These heat sinks are made of copper or lighter and stronger composites consisting of copper and graphene nanoparticles.
Metal-graphene particles are obtained through plasma-chemical synthesis, during which the initial components of the composite interact while moving in a plasma jet, resulting in the formation of nanoparticles with a metal core and a graphene sheet shell. These composites combine the lightness and strength of graphene with the high thermal and electrical conductivity of metals.
This method has been tested by the scientists from the Institute for Metals Superplasticity Problems RAS and the Joint Institute for High Temperatures RAS. To obtain plasma, the authors used a plasmatron with an electric arc torch made of pure copper. Plasma flow generation resulted in the separation of copper nanoparticles (ranging in size from 1 to 100 nanometers). A plasma jet was formed in a mixture of two gases, propane and butane, thanks to which single-layer graphene flakes were synthesized. Copper-graphene composite structures were formed when copper nanoparticles collided with single-layer graphene sheets.
In order to analyze the structure of the new composite, the scientists conducted a molecular dynamics simulation. The authors set various directions and speeds of movement for copper nanoparticles in the model (from 0.5 to 9 km per second). At relatively low speeds of nanoparticles (less than 1 km per second), copper collides with a graphene flake and attaches to it; at medium speeds (1–5 km per second), it gets enveloped in graphene like in a candy wrapper; at high speeds (more than 7 km per second), it tears the graphene sheet apart by flying through it. Later on, these results could facilitate the production of copper-graphene composites with the most perfect morphology.
“In the future, we plan to study the physical and mechanical properties of such unique copper-graphene composites. As early as today, we have managed to predict the high strength properties of these materials through atomistic modeling, and this will undoubtedly expand the scope of application of new copper-graphene composites synthesized in a plasma jet,” Karina Krylova, candidate of physical and mathematical sciences, is quoted as saying by the Institute for Metals Superplasticity Problems RAS.
