The Influence of Carbon Nanotube Aspect Ratio on Thermal Conductivity Enhancement in Nanotube–Polymer Composites

Abstract

We report and model a linear increase in the thermal conductivity (κ) of polymer composites incorporated with relatively low length/diameter aspect ratio multiwalled carbon nanotubes (CNTs). There was no evidence of percolation-like behavior in the κ, at/close to the theoretically predicted threshold, which was attributed due to the interfacial resistance between the CNT and the polymer matrix. Concomitantly, the widely postulated high thermal conductivity of CNTs does not contribute to the net thermal conductivity of the composites. Through estimating the interfacial resistance and the thermal conductivity of the constituent CNTs, we conclude that our experimental and modeling approaches can be used to study thermal transport behavior in nanotube–polymer composites.