Self-reconstruction and predictability of bonds disruption in twisted graphene nanoribbons

Graphene nanoribbons are of great interest due to their applications in nanosized circuitry, where the former can undergo several mechanical deformations, as for example strains and twists. Although there are many investigations about twisted graphene nanoribbons, no density functional calculations are presented concerning their structural integrity when these ribbons are twisted by large angles. In order to investigate this, here are reported first principles calculations on twisted graphene nanoribbons. The results show that for most structures, the system undergoes a transition where it self-reconstructs to the original nanoribbon after twisting beyond a specific angle. This twist angle depends linearly on the nanoribbon length and has a non-linear behavior with the width. Also one finds that it is easier to twist an armchair graphene nanoribbon than a zigzag one when both have the same width and length. In addition, it was performed a simple classical model by applying tensile strain where its agreement with the density functional calculations becomes better for wider graphene nanoribbons, indicating that it is possible to estimate the maximum twist angle knowing only geometric data. This information could be used in prevention ruptures due to twists of the graphene nanoribbons present in nanosized circuitry with flexible shape. (C) 2014 AIP Publishing LLC.