Interface heat transfer between crossing carbon nanotubes, and the thermal conductivity of nanotube pellets

TL;DR

This paper models the interface heat transfer between crossing carbon nanotubes and estimates the thermal conductivity of nanotube pellets, revealing they could serve as effective thermal insulators due to their relatively low conductivity.

Contribution

It introduces a theoretical approach to compute interface thermal resistance between crossing nanotubes and applies it to estimate pellet conductivity, highlighting the insulating potential.

Findings

Pellet thermal conductivity is a few W/m-K for 1 μm nanotubes.

Interface thermal resistance significantly affects pellet conductivity.

Nanotube pellets may function as thermal insulators.

Abstract

We theoretically compute the interface thermal resistance between crossing single walled carbon nanotubes of various chiralities, using an atomistic Green's function approach with semi-empirical potentials. The results are then used to model the thermal conductivity of three dimensional nanotube pellets in vacuum. For an average nanotube length of 1 $\mu$m, the model yields an upper bound for the thermal conductivity of densely compacted pellets, of the order of a few W/m-K. This is in striking contrast with the ultra-high thermal conductivity reported on individually suspended nanotubes. The results suggest that nanotube pellets might have an application as thermal insulators.