Helical Wrapping and Insertion of Graphene Nanoribbon to Single-Walled Carbon Nanotube

Molecular dynamics simulations are performed to demonstrate that the graphene nanoribbon (GNR) could helically wrap onto and insert into the single-walled carbon nanotube (SWNT) to form helical configurations,. which are quite close to the helices found in nature. The steady decline of the potential energy suggests that the helical wrapping and insertion are spontaneous. The van der Waals interaction, pi-pi stacking interaction between the GNR and the SWNT, and dangling a-orbitals on carbon atoms at open edges of GNR are all responsible for these unique phenomena. Two GNRs would form a DNA-like double-helix with the same handedness. The dependence of the diameter and chirality of SWNT and the width of GNR in the helix-forming process are investigated. The gaps on the tube walls are not good at the helical wrapping and insertion. In addition, we explore the possibility of using the spontaneous wrapping and insertion of GNRs to deliver substances. These unique properties are expected to provide novel strategies to design nanoscale vehicles and substantial functional devices.