Maximum thermal conductivity of aligned single wall carbon nanotubes

TL;DR

This paper estimates the maximum thermal conductivity of perfectly aligned single wall carbon nanotube bundles, considering segment length and phonon scattering, predicting values consistent with experimental data.

Contribution

It introduces a model for maximum thermal conductivity of aligned nanotubes based on segment length and phonon scattering effects.

Findings

Maximum thermal conductivity ~300 W/m·K for 1 micron tubes.

Effective phonon mean free path ~ L/7.

Model aligns with experimental results assuming segment length ~1 micron.

Abstract

I estimate maximum thermal conductivity $\kappa$ of a perfectly aligned bundle of single wall carbon nanotubes. Each row of aligned nanotubes has a discrete structure. It consists of segments of nanotubes with length $L$. The spacing between the segments block the phonon path through the row. Only the scattering due to the finite length of the segments is taken into account. The result is that the 'effective'' mean free path is of the order of $L/7$. For 1 micron tubes (10,10) we get maximum value of $\kappa\approx 300$W/m K at room temperature. This result is in a reasonable agreement with the experiment by Hone {\it et al.} assuming that in their samples $L\approx 1\mu{\rm m}$