Carbon nanotubes collapse phase diagram with arbitrary number of walls. Collapse modes and macroscopic analog

TL;DR

This paper develops a predictive model for the collapse of carbon nanotubes considering diameter, wall number, and pressure, supported by simulations and experiments, and explores the multiscale analogy with macroscopic tubes.

Contribution

It introduces a simple, general model for nanotube collapse predicting stability limits across various configurations, validated by atomistic simulations and experiments.

Findings

Maximum supported pressure of 18 GPa for a multiwall nanotube.

Collapse phase diagrams as a function of diameter, walls, and pressure.

Identification of a diameter domain where nanotube stability parallels macroscopic tubes.

Abstract

Carbon nanotubes tend to collapse when their diameters exceed a certain threshold, or when a sufficiently large external pressure is applied on their walls. Their radial stability of tubes has been studied in each of these cases, however a general theory able to predict collapse is still lacking. Here, we propose a simple model predicting stability limits as a function of the tube diameter, the number of walls and the pressure. The model is supported by atomistic simulations, experiments, and is used to plot collapse phase diagrams. We have identified the most stable carbon nanotube, which can support a maximum pressure of 18 GPa before collapsing. The latter was identified as a multiwall tube with an internal tube diameter of 12nm and 30 walls. This maximum pressure is lowered depending on the internal tube diameter and the number of walls. We then identify a tube diameter domain in which the radial mechanical stability can be treated as equivalent to macroscopic tubes, known to be described by the canonical L\'evy-Carrier law. This multiscale behavior is shown to be in good agreement with experiments based on O-ring gaskets collapse, proposed as a simple macroscopic parallel to nanotubes in this domain.