Atomistic Computational Modeling of Temperature Effects in Fracture Toughness and Degradation of Penta-graphene Monolayer

Abstract: The novel carbon allotrope with particular and unique 2D arrangement of carbon atoms similar to a Cairo pentagonal tiling, with interplay of $sp^{3}$ and $sp^{2}$ hybridized carbon atoms is called of Penta-graphene (PG). Previous theoretical investigations have shown that PG monolayer is mechanically and thermodynamically stable, possessing also a large band gap of $3.25eV$. This new carbon allotrope with unique carbon atom arrangement in a network (non-coplanar pentagons) is the focus of the theoretical investigations in this work. Using the non-equilibrium molecular dynamics simulations with reactive modern force field ReaxFF, we performed computational modeling of the nanostructural, dynamics e mechanical properties of penta-graphene monolayer under high temperature conditions. We obtained in our results the effect of the temperature in mechanical properties of penta-graphene monolayer up to $2000K$, where our results show that strain rate was strong effect on the mechanical properties with reduction of the $67$\%, reduction in the Ultimate Tensile Streght (UTS) $ 35.88 - 11.83GPa.nm $ and Young's Modulus ($Y_{Mod}$) of the $ 227.15 - 154.76GPa.nm $. In this work we also calculated the reactive degradation of monolayer of penta-graphene at temperatures changes of $10K$ up to $2000K$. Thus, our averages show that penta-graphene monolayer loss atomic configurations with temperature effect up to $600K$, where the monolayer show nanostructural transition with several islands of graphene, large regions of porosity, small 1D carbon chains, and also negative curved layer.