Model for the effective thermal conductivity of carbon nanotube composites

Abstract

We present a novel model of the effective thermal conductivity for carbon nanotubecomposites by incorporating the interface thermal resistance with an average polarizationtheory. The dependence of the effective thermal conductivity on nanotube length, diameter,concentration, and interface thermal resistance has been taken care of simultaneously inour treatment. The model predicts that the large length of the carbon nanotubes embeddedplays a key role in the thermal conductivity enhancement, while the large interface thermalresistance across the nanotube–matrix interface causes a significant degradation.Interestingly, the model predicts that the nanotube diameter has a very smalleffect on the thermal conductivity enhancement of the nanotube composites.In addition, the model predicts that the thermal conductivity enhancement ofnanotube composites increases rapidly with decreasing the thermal conductivity ofthe matrix and increases with increasing the thermal conductivity of the carbonnanotube. Predictions from the novel model are in excellent agreement with theexperimentally observed values of the effective thermal conductivity of carbonnanotube nanofluids which the classical models have not been able to explain.