Temperatural conductivity of diluted water solutions graphen and nanostructures of graphen nanoparticles

Abstract

The purpose of this work was to study the specific thermal conductivity of aqueous graphene dispersions and the diluted aqueous solution of nanostructures based on graphene and Au nanoparticles, as well as to determine the temperature and concentration dependences of the specific thermal conductivity of these aqueous dispersions. The objects of study were aqueous dispersions of graphene and nanostructures based on graphene and Au nanoparticles. Graphene has characteristic dimensions of the order of 150 - 200 nm in the plane. The Au nanoparticles also have an average size of about 50 nm and a star-like shape. In dry nanocomposites, graphene is oriented parallel to the substrate plane, and nanostars are evenly distributed on the sample surface. The specific volumetric thermal conductivity values of aqueous graphene dispersions and aqueous solutions of graphene-based nanoparticles and Au nanoparticles were obtained in the temperature range from 30оC to 60оC. A slight increase in the specific thermal conductivity was found with increasing temperature. The absolute values a/v of aqueous graphene dispersions are 1.6 times higher than in three-component systems. The concentration dependences of the thermal conductivity of the two systems studied are linear. It is determined that the values of the specific thermal conductivity of dry graphene nanofillers are 1,62 times higher than the thermal conductivity of a mixture of graphene and Au nanoparticles.