Elastic properties of SWCNTs with curved morphology: Density functional tight binding based treatment

The self-consistent charge density functional based tight-binding method is used to calculate the effect of curvature on the structure, average energy of atoms and Young's modulus of armchair single-wall carbon nanotubes (SWCNTs) under axial strains. We found that as the amount of curvature increases, the average energy of atoms and the Young's modulus decrease and the equilibrium CC distance increases for (7,7) SWCNTs. However, we also found that the average energy of atoms and Young's modulus of (5,5) SWCNTs are weakly affected by increasing the amount of curvature. Our results also show that the average energy of atoms and Young's modulus of smaller diameter armchair nanotubes are smaller than that of the larger diameter ones.

► A TEM image of the morphology and geometry of as-grown SWCNTs is obtained.
► Theoretical calculations on the structural and mechanical properties of armchair SWCNTs with curved morphology are considered.
► State of the art density functional theory calculations are performed.
► The effects of the curvatures on the moduli of nanotubes with different diameters are considered.
► The Young′s moduli of smaller diameter nanotubes are smaller than that of the larger diameter ones.