Mechanical Properties of Phagraphene Membranes: A Fully Atomistic Molecular Dynamics Investigation

TL;DR

This study uses atomistic molecular dynamics simulations to analyze the mechanical behavior and fracture patterns of phagraphene membranes, revealing distinct elastic, ripple, and plastic deformation regimes.

Contribution

It provides a comprehensive, atomistic-level analysis of phagraphene's mechanical properties, including fracture behavior, which was previously lacking.

Findings

Young's modulus estimated from stress-strain curves

Identification of three deformation regimes: ripple, elastic, plastic

Mechanical failure occurs after plastic deformation

Abstract

Recently, a new 2D carbon allotrope structure, named phagraphene (PG), was proposed. PG has a densely array of penta-hexa-hepta-graphene carbon rings. PG was shown to present low and anisotropic thermal conductivity and it is believed that this anisotropy should be also reflected in its mechanical properties. Although PG mechanical properties have been investigated, a detailed and comprehensive study is still lacking. In the present work we have carried out fully atomistic reactive molecular dynamics simulations using the ReaxFF force field, to investigate the mechanical properties and fracture patterns of PG membranes. The Young's modulus values of the PG membranes were estimated from the stress-strain curves. Our results show that these curves present three distinct regimes: one regime where ripples dominate the structure and mechanical properties of the PG membranes; an elastic regime where the membranes exhibit fully planar configurations; and finally a plastic regime where permanent deformations happened to the PG membrane up to the mechanical failure or fracture.