Coupled thermo-mechanics of single-wall carbon nanotubes

TL;DR

This study investigates how the mechanical properties of single-wall carbon nanotubes change with temperature, revealing decreases in stiffness and increases in Poisson's ratio, with predictions aligning with molecular dynamics results.

Contribution

It provides a temperature-dependent mechanical model for nanotubes using molecular mechanics, highlighting the variation of properties with chirality and temperature.

Findings

Stiffness decreases as temperature increases.

Poisson's ratio increases with temperature.

Model agrees with Molecular Dynamics simulations.

Abstract

The temperature-dependent transverse mechanical properties of single-walled nanotubes are studied using a molecular mechanics approach. The stretching and bond angle force constants describing the mechanical behaviour of the sp^{2} bonds are resolved in the temperature range between 0 K and 1600 K, allowing to identify a temperature dependence of the nanotubes wall thickness. We observe a decrease of the stiffness properties (axial and shear Young's modulus) with increasing temperatures, and an augmentation of the transverse Poisson's ratio, with magnitudes depending on the chirality of the nanotube. Our closed-form predictions compare well with existing Molecular Dynamics simulations.