Enhanced thermal conductivity of epoxy composites by introducing graphene@boron nitride nanosheets hybrid nanoparticles.

Polymer composites with high thermal conductivity have promising applications for the thermal management of modern electronic devices. Here, a novel strategy is proposed to enhance the thermal conductivity of epoxy composites by employing a hybrid graphene and boron nitride nanoparticle (GBN). In the GBN, boron nitride nanosheets (BNNSs) tightly adsorb onto the surface of graphene via π-π interactions, and act as bridges for conveying phonons as well as barriers for electrons transporting between adjacent graphene particles. The thermal conductivity and dielectric properties of composites containing GBN are then systematically investigated. The thermal conductivity is significantly enhanced (~140%) in GBN/epoxy composites containing only 5 wt% of GBN. High electrical resistivity (3.05 × 1012 Ω·cm) and low dielectric loss (tan δ < 0.08) are also observed. This study provides important insights into the design and fabrication of highly thermally conductive and electrically insulating composites. Unlabelled Image • Hybrid nanoparticles consisting of graphene and boron nitride nanosheets are prepared by combination of sonication and hydrothermal treatment. • Boron nitride nanosheets act as bridges for phonons conveying as well as barriers for electrons transporting between adjacent graphene particles. • Significant thermal conductivity enhancement is achieved at a low hybrid filler loading. [ABSTRACT FROM AUTHOR]