The synergistic effect of a hybrid filler based on graphene nanoplates and multiwalled nanotubes for increasing the thermal conductivity of an epoxy composite

A hybrid heat-conducting filler based on graphene nanoplates and multiwalled carbon nanotubes for increasing the thermal conductivity of an epoxy binder has been synthesized, which exhibits a synergistic effect. This effect is achieved as a result of embedding carbon nanotubes between graphene nanoplates and the formation of effective percolation networks in the composite. The dependence of the increase in the thermal conductivity increase of an epoxy composite on the mass ratio of nanotubes and nanoplates in a hybrid filler mixture has been established. It has been found that the concentration of the hybrid filler in the epoxy matrix and the method of mixing nanoplates and nanotubes have an effect on the thermal conductivity of the composite. A synergistic effect between nanoplates and nanotubes has been demonstrated, which leads to a fivefold increase in the thermal conductivity of epoxy composites at a filler concentration of 5 wt%.