Twisting Carbon Nanotubes: A Molecular Dynamics Study

TL;DR

This study uses molecular dynamics simulations to analyze how different types and sizes of carbon nanotubes respond to twisting, revealing size-dependent mechanical properties and structural transformations before fracture.

Contribution

It provides new insights into the twisting behavior of various carbon nanotubes, including multi-walled and different chiralities, using atomic-scale simulations.

Findings

Larger nanotubes are harder to twist than smaller ones.

Zigzag multi-walled nanotubes withstand more deformation than armchair types.

Structural defects form prior to nanotube fracture.

Abstract

We simulate the twist of carbon nanotubes using atomic molecular dynamic simulations. The ultimate twist angle per unit length and the deformation energy are calculated for nanotubes of different geometries. It is found that the big tube is harder to be twisted while the small tube exhibits higher ultimate twisting ratio. For multi-walled nanotubes, the zigzag tube is found to be able to stand more deformation than the armchair one. We observed the surface transformation during twisting. Formation of structural defects is observed prior to fracture.