Mechanical properties of pristine and nanoporous graphene

Anthea Agius Anastasi, Konstantinos Ritos, Glenn Cassar, Matthew K. Borg

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

We present molecular dynamics simulations of monolayer graphene under uniaxial tensile loading. The Morse, bending angle, torsion and Lennard-Jones potential functions are adopted within the mdFOAM library in the OpenFOAM software, to describe the molecular interactions in graphene. A well-validated graphene model using these set of potentials is not yet available. In this work, we investigate the accuracy of the mechanical properties of graphene when derived using these simpler potentials, compared to the more commonly used complex potentials such as the Tersoff-Brenner and AIREBO potentials. The computational speed-up of our approach, which scales O(1.5N), where N is the number of carbon atoms, enabled us to vary a larger number of system parameters, including graphene sheet orientation, size, temperature and concentration of nanopores. The resultant effect on the elastic modulus, fracture stress and fracture strain is investigated. Our simulations show that graphene is anisotropic, and its mechanical properties are dependant on the sheet size. An increase in system temperature results in a significant reduction in the fracture stress and strain. Simulations of nanoporous graphene were created by distributing vacancy defects, both randomly and uniformly, across the lattice. We find that the frac- ture stress decreases substantially with increasing defect density. The elastic modulus was found to be constant up to around 5% vacancy defects, and decreases for higher defect densities.
LanguageEnglish
Pages1-10
Number of pages10
JournalMolecular Simulation
DOIs
Publication statusPublished - 14 Sep 2016

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Graphite
Graphene
Mechanical Properties
graphene
mechanical properties
Mechanical properties
Defects
Defect density
Vacancy
defects
Elastic Modulus
Vacancies
modulus of elasticity
Elastic moduli
Lennard-Jones potential
Nanopore
Lennard-Jones Potential
Decrease
Complex Potential
Nanopores

Keywords

  • graphene
  • molecular dynamics
  • fracture
  • elastic modulus
  • vacancy defects

Cite this

Agius Anastasi, Anthea ; Ritos, Konstantinos ; Cassar, Glenn ; Borg, Matthew K. / Mechanical properties of pristine and nanoporous graphene. In: Molecular Simulation. 2016 ; pp. 1-10.
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Mechanical properties of pristine and nanoporous graphene. / Agius Anastasi, Anthea; Ritos, Konstantinos; Cassar, Glenn; Borg, Matthew K.

In: Molecular Simulation, 14.09.2016, p. 1-10.

Research output: Contribution to journalArticle

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