Mechanical properties of bulk carbon nanomaterials

Bulk carbon nanomaterials, which open prospects for the development of a new generation of supercapacitors, are actively investigated for recent years, but their mechanical properties and structure remain poorly understood. In connection with this fact, the influence of the hydrostatic and uniaxial compression on mechanical properties and structure of three bulk nanomaterials consisting of (i) bent graphene flakes, (ii) short carbon nanotubes, and (iii) fullerenes C$_{240}$ are investigated by the molecular dynamics method. It is shown that the strength of the material and its stability to graphitization depend on its constituent structural units. At large degrees of deformation, the material consisting of bent graphene sheets has the highest strength, whereas at the material density lower than 2.5 g/cm$^3$, the highest strength is observed in the nanomaterial consisting of fullerene molecules. The differences in mechanical properties of the materials under consideration are explained by their structural features.