Multistability of carbon nanotube packings on flat substrate

TL;DR

This study uses molecular dynamics to demonstrate that multilayer packings of single-walled carbon nanotubes on flat substrates exhibit multistability, with multiple stable states influenced by nanotube collapse, affecting the package's thickness.

Contribution

It reveals the multistability of nanotube packings and characterizes how collapse influences the stable states and thickness variations, a novel insight into nanotube assembly behavior.

Findings

Multiple stable states exist for nanotube packings.

Collapse of nanotubes reduces the package thickness.

All stationary states are thermally stable at 300K.

Abstract

It is shown by the method of molecular dynamics using a chain model that a multilayer packaging of identical single-walled carbon nanotubes with a diameter of D>2.5 nm located on a flat substrate is a multistable system. The system has many stationary states, which are characterized by the portion of collapsed nanotubes. The thickness of the package monotonically decreases with an increase in the portion of such nanotubes. For nanotubes with a chirality index (60,0), depending on the portion of collapsed nanotubes, the thickness of the 11-layer package can vary from 12 to 36 nm. All stationary states of the package are stable to thermal fluctuations at T=300K. The transverse compression of the package is not elastic; due to the collapse of a part of the nanotubes, it only transfers the package from one stationary state to another with a smaller thickness.