High impact resistance in graphyne

2013

Molecular dynamics simulations are used to study the mechanical properties of graphynes. To study the effect of atomic structure and graphyne size on the Young’s and bulk modulus, armchair and zigzag nanosheets with different side lengths and aspect ratios are considered. It is shown than the fracture of armchair graphynes occurs at larger strains. Comparing Young’s modulus of armchair and zigzag nanosheets with a constant aspect ratio, it is observed that the value of side length have not significant effect on the Young’s modulus of graphynes. Besides, the schematic of graphynes axial and biaxial loading at different strains is represented.it is shown that fracture propagates in a linear pattern

Journal of Applied Physics, 2013

Physical Chemistry Chemical Physics, 2012

We investigated the mechanical properties of graphyne monolayers using first-principles calculations based on the Density Functional Theory. Graphyne has a relatively low in-plane Young's modulus (162 N m À1 ) and a large Poisson ratio (0.429) compared to graphene. It can sustain large nonlinear elastic deformations up to an ultimate strain of 0.2 followed by strain softening until failure. The single bond is more vulnerable to rupture than the triple bond and aromatic bond, although it has a shorter bond length (0.19 Å shorter) than the aromatic bond. A rigorous continuum description of the elastic response is formulated by expanding the elastic strain energy density in a Taylor series in strain truncated after the fifth-order term. We obtained a total of fourteen nonzero independent elastic constants which are components of tensors up to the tenth order. Pressure effects on the second-order elastic constants, in-plane Young's modulus, and Poisson ratio are predicted. This study implies that graphyne-based surface acoustic wave sensors and waveguides may be synthesized by introducing precisely controlled local strains on graphyne monolayers.

arXiv (Cornell University), 2023

Graphyne is a two-dimensional carbon allotrope of graphene. Its structure is composed of aromatic rings and/or carbon-carbon bonds connected by one or more acetylene chains. As some graphynes present the most of the excellent properties of graphene and non-null bandgap, they have been extensively studied. Recently, Kanegae and Fonseca reported calculations of four elastic properties of 70 graphynes, ten members of the seven families of graphynes [Carbon Trends 7, 100152 (2022)]. They showed that the acetylene chain length dependence of these properties can be simply modelled by a serial association of springs. Here, based on those results, we present the density dependence of these properties and show that the elastic moduli, E, of graphyne are less dependent on density, ρ, than porous cellular materials with an exponent of E ~ ρ n , smaller than 2. We discuss the results in terms of the shape of the pores of the graphyne structures.

2012

We investigated the mechanical properties of graphyne monolayer using first-principles calculations based on the Density Functional Theory. Graphyne has a relatively low in-plane Young's modulus (162 N/m) and a large Poisson ratio (0.429) compared to graphene. It can sustain large nonlinear elastic deformations up to an ultimate strain of 0.2 followed by a strain softening until failure.

Crystals, 2018

Graphyne is a two-dimensional carbon allotrope with superior one-dimensional electronic properties to the "wonder material" graphene. In this study, via molecular dynamics simulations, we investigated the mechanical properties of α-, β-, δ-, and γ-graphynes with various type of point defects and cracks with regard to their promising applications in carbon-based electronic devices. The Young's modulus and the tensile strength of the four kinds of graphyne were remarkably high, though still lower than graphene. Their Young's moduli were insensitive to various types of point defects, in contrast to the tensile strength. When a crack slit was present, both the Young's modulus and tensile strength dropped significantly. Furthermore, the Young's modulus was hardly affected by the strain rate, indicating potential applications in some contexts where the strain rate is unstable, such as the installation of membranes.

Carbon, 2018

Graphdiyne possesses not only high strength but also excellent ductility, making it possible to be used in future high-performance protective structures. In this paper, the mechanical properties of graphdiyne were firstly measured by AFM experiments, and the failure behavior during low velocity perforation was also investigated by molecular dynamics (MD) simulations. Firstly, the elastic modulus was measured to be about 218.5 GPa by AFM experiments, which is about half of its ideal value due to various defects and the layer numbers of the synthesized graphdiyne film. Then, the nanoindentation processes of graphdiyne films were investigated by MD simulations, and the elastic modulus and strength were simulated to be about 489.04 GPa and 33.95 GPa, respectively. The failure behavior of the graphdiyne film was also studied in atomic level. Sequential broken of C^C, C]C and CeC bonds and recombination of the broken bonds were observed to form a unique lathy crack. Furthermore, the effects of loading speed and indenter radius on the mechanical response of graphdiyne were investigated. A revised formula was developed for analyzing the mechanical properties of films in AFM experiments under various loading conditions.

The Journal of Physical Chemistry Letters, 2014

Graphynes are novel two-dimensional carbon-based materials that -due to their nanoweblike structure-have been proposed as molecular filters, especially for water purification technologies. In this work we carry out first principles electronic structure calculations at the MP2C level of theory to assess the interaction between water and graphyne, graphdiyne and graphtriyne pores. The computed penetration barriers suggest that water transport is unfeasible through graphyne while being unimpeded for graphtriyne. Nevertheless, for graphdiyne, which presents a pore size almost matching that of water, a low barrier is found which in turn disappears if an active hydrogen bond with an additional water molecule on the opposite side of the opening is taken into account. These results support the possibility of using graphtriyne as an efficient membrane for water filtration but, in contrast with previous determinations, they do not exclude graphdiyne. In fact, the related first principles penetration barrier leads to water permeation probabilities which are at least two order of magnitude larger than those estimated by employing commonly used force fields. A new pair potential for the water-carbon noncovalent component of the interaction has been built and it is recommended for molecular dynamics simulation involving graphdiyne and water. Graphynes were first predicted by Baughman et al. 1 and can be considered as a family of new 2D carbon allotropes formed by sp-sp 2 hybridized carbon atoms. They can be thought as deriving from graphene by replacing one-third of its C-C bonds with mono(poly)-acetylenic units. The number N of acetylenic linkages which connect the benzene rings defines the different graphyne-N species and the first four members of the family are known as graphyne, graphdiyne, graphtriyne and graphtetrayne, respectively. 2 Among them graphdiyne is possibly to date the most interesting species since its thin films have been recently synthesized on top of copper substrates. 3 This advance has triggered many studies on related nanostructures. Recent theoretical studies suggest that freestanding graphynes' layers are not only chemically inert and stable under ambient tempera-

MRS Advances, 2017

Graphynes and graphdiynes are carbon 2D allotrope structures presenting both sp2 and sp hybridized atoms. These materials have been theoretically predicted but due to intrinsic difficulties in their synthesis, only recently some of these structures have been experimentally realized. Graphyne nanoscrolls are structures obtained by rolling up graphyne sheets into papyrus-like structures. In this work, we have investigated, through fully atomistic reactive molecular dynamics simulations, the dynamics of nanoscroll formation for a series of graphyne (α, β, and δ types) structures. We have also investigated their thermal stability for a temperature range of 200-1000K. Our results show that stable nanoscrolls can be formed for all structures considered here. Their stability depends on a critical value of the ratio between length and height of the graphyne sheets. Our findings also show that these structures are structurally less stable then graphene-based nanoscrolls. This can be explaine...

Nanomaterials

The development of armour systems with higher ballistic resistance and light weight has gained considerable attention as an increasing number of countries are recognising the need to build up advanced self-defence system to deter potential military conflicts and threats. Graphene is a two dimensional one-atom thick nanomaterial which possesses excellent tensile strength (130 GPa) and specific penetration energy (10 times higher than steel). It is also lightweight, tough and stiff and is expected to replace the current aramid fibre-based polymer composites. Currently, insights derived from the study of the nacre (natural armour system) are finding applications on the development of artificial nacre structures using graphene-based materials that can achieve high toughness and energy dissipation. The aim of this review is to discuss the potential of graphene-based nanomaterials with regard to the penetration energy, toughness and ballistic limit for personal body armour applications. T...