Collapse of Double-Walled Carbon Nanotube Bundles under Hydrostatic Pressure

TL;DR

This study uses molecular dynamics simulations to analyze how single and double-walled carbon nanotube bundles collapse under hydrostatic pressure, revealing scaling laws and mechanical support mechanisms.

Contribution

It introduces a detailed simulation-based analysis of collapse behavior and derives a scaling law for collapse pressure in DWNTs using elastica theory.

Findings

Collapse pressure scales as 1/R^3.

DWNT collapse pressure is approximately the sum of inner and outer tube contributions.

Inner tubes support outer tubes, doubling the effective bending stiffness.

Abstract

We use classical molecular dynamics simulations to study the collapse of single (SWNT) and double-walled (DWNT) carbon nanotube bundles under hydrostatic pressure. The collapse pressure (pc) varies as 1/R^3, where R is the SWNT radius or the DWNT effective radius. The bundles show ~ 30% hysteresis and the hexagonally close packed lattice is completely restored on decompression. The pc of DWNT is found to be close to the sum of its values for the inner and the outer tubes considered separately as SWNT, demonstrating that the inner tube supports the outer tube and that the effective bending stiffness of DWNT, D(DWNT) ~ 2D(SWNT) . We use an elastica formulation to derive the scaling and the collapse behavior of DWNT and multi-walled carbon nanotubes.