A comprehensive study on the mechanical properties and failure mechanisms of graphyne nanotubes (GNTs) in different phases

The mechanical properties, failure mechanisms of one-dimensional carbon allotropes including α, β, γ graphyne nanotubes (GNTs) and also conventional carbon nanotubes (CNTs) were calculated by using classical molecular dynamics simulations. The GNTs was showed unique properties due to the presence of single, double and triple bonds in their crystal lattice compared to CNTs. It was found that the α-GNT phase has had an ability for typical plastic behavior due to the presence of the acetylenic linkages and the atoms reconstruction processes. The effects of acetylenic linkages on the mechanical properties of different phases of GNTs including fracture behavior, Young's modulus, and Poisson's ratio were also investigated under uniaxial tension. Among GNTs, α-GNTs exhibited the lowest fractures stresses and Young's modulus, while γ-GNTs showed the highest fractures stress and Young's modulus. Moreover, GNTs had a higher Poisson's ratio due to possessing a higher variety of pore sizes compared to CNTs. These features made the GNTs suitable for many different applications and open up a novel view for the study of plastic carbon-based nanomaterials. As well as, based on the visualization of the nanotubes fractures, the failure mechanism of the nanotubes was analyzed and discussed. © 2020 Elsevier B.V.