Mechanical Properties of Pentagraphene-based Nanotubes: A Molecular Dynamics Study

TL;DR

This study investigates the mechanical properties of pentagraphene nanotubes (PGNTs) using molecular dynamics simulations, revealing their high Young's modulus and unique fracture behaviors compared to carbon nanotubes.

Contribution

It introduces a detailed molecular dynamics analysis of PGNTs, highlighting their elastic properties and fracture patterns, which are distinct from traditional carbon nanotubes.

Findings

PGNTs have Young's modulus around 800 GPa.

PGNTs exhibit chirality-dependent fracture patterns.

Structural reconstructions occur during failure.

Abstract

The study of the mechanical properties of nanostructured systems has gained importance in theoretical and experimental research in recent years. Carbon nanotubes (CNTs) are one of the strongest nanomaterials found in nature, with Young's Modulus (YM) in the order 1.25 TPa. One interesting question is about the possibility of generating new nanostructures with 1D symmetry and with similar and/or superior CNT properties. In this work, we present a study on the dynamical, structural, mechanical properties, fracture patterns and YM values for one class of these structures, the so-called pentagraphene nanotubes (PGNTs). These tubes are formed rolling up pentagraphene membranes (which are quasi-bidimensional structures formed by densely compacted pentagons of carbon atoms in sp3 and sp2 hybridized states) in the same form that CNTs are formed from rolling up graphene membranes. We carried out fully atomistic molecular dynamics simulations using the ReaxFF force field. We have considered zigzag-like and armchair-like PGNTs of different diameters. Our results show that PGNTs present YM ~ 800 GPa with distinct elastic behavior in relation to CNTs, mainly associated with mechanical failure, chirality dependent fracture patterns and extensive structural reconstructions.