Rotational dynamics and friction in double-walled carbon nanotubes

TL;DR

This study investigates the rotational behavior and frictional forces in double-walled carbon nanotubes through molecular dynamics simulations and analytical modeling, revealing linear relationships and temperature-dependent relaxation times.

Contribution

It introduces a combined molecular dynamics and analytical approach to understand rotational friction and relaxation times in double-walled nanotubes, highlighting key dependencies.

Findings

Friction force is linear with angular velocity.

Relaxation time depends only on interlayer spacing and temperature.

Friction increases linearly with contact area.

Abstract

We report a study of the rotational dynamics in double-walled nanotubes using molecular dynamics simulations and a simple analytical model reproducing very well the observations. We show that the dynamic friction is linear in the angular velocity for a wide range of values. The molecular dynamics simulations show that for large enough systems the relaxation time takes a constant value depending only on the interlayer spacing and temperature. Moreover, the friction force increases linearly with contact area, and the relaxation time decreases with the temperature with a power law of exponent $-1.53 \pm 0.04$.