Twisting of graphene nanoribbons partially located on flat substrates

The molecular dynamics simulation of longitudinal twisting of graphene nanoribbons hanging from the edge of a flat substrate formed by the surface of a hexagonal boron nitride crystal has been performed. It has been shown that rotation of the free end of a nanoribbon causes twisting of the suspended region accompanied by monotonous sliding of the nanoribbon over the substrate. At the beginning, a regular screw-like shape is formed in the suspended section, next a super-twisted section emerges inside it, further growth of which occurs due to pulling of the nanoribbon from the substrate. After separation from the substrate, the twisted nanoribbon folds into a roll, so that further twisting results only in free rotation of the roll. Copyright (C) 2020 EPLA