Enhancing thermal transport efficiency in carbon composites using nanospacers

Abstract

Improved thermal transport efficiency of carbon-based composites has been achieved by inserting metallic spacers within the temperature range of 50–150 °C. Al₂O₃, Ni, and SnO nano-particles are used as nanospacers in the graphite-like thin films, forming well-developed carbon framework. The composites show 42.5–57.7% increase in thermal conductivity (k), as compared with the pristine carbon. Among all the samples Al-inserted carbon composites exhibited the highest k value of 1128 W m⁻¹ K⁻¹ at 50 °C. The metallic nanopowders serve not only as filler but also as connective points for creating additional path for the heat conduction, leading to highly-efficient thermal diffusion. The apparent k value is found to be an increasing function of electrical conductivity, revealing that the conduction of free electrons is analogous to the thermal transport. The present work provided useful information concerning the thermal conduction and heat dissipation efficiencies of carbon-based composites, benefiting the design of thermal devices, e.g., heat sink and heat exchanger.