Vadym Mochalin1 Vadym Borysiuk2 Yury Gogotsi3

1, Missouri University of Science and Technology, Rolla, Missouri, United States
2, Sumy State University, Sumy, , Ukraine
3, Drexel University, Philadelphia, Pennsylvania, United States

Two-dimensional (2D) materials beyond graphene are attracting much attention due to their unique properties. 2D carbides and nitrides of transition metals (MXenes) have shown very attractive electrical and electrochemical properties, but their mechanical behavior has been poorly characterized. There are no experimental measurements of intrinsic mechanical properties of MXenes reported in the literature and only a handful of theoretical data on strength, fracture modes, Young’s modulus, and bending rigidity for single-layer MXenes.
The mechanical properties of two-dimensional titanium carbides (Ti2C, Ti3C2, and Ti4C3) were investigated in this study by performing in silico experiments using large scale classical molecular dynamics. Young’s modulus was calculated from the linear part of strain–stress curves obtained under tensile deformation of the samples. Strain-rate effects were observed for all Tin+1Cn samples. Dynamical behavior of the samples under external bending load was simulated via classical molecular dynamics. The central deflection and bending rigidity of the MXene nanoribbons were calculated as functions of applied force. Calculated bending rigidity of the Ti2C nanoribbon is 5.21 eV at small deflections and nonlinearly increases at larger deflections, reaching the maximum magnitude of 12.79 eV before the onset of disintegration. We discuss these properties in comparison to mechanical properties of other 2D materials and emphasize the importance of the advanced mechanical properties of MXenes in applications.