Triangular graphene nanosheets, structures with extraordinary bending behavior.

Abstract

Sometimes, manipulating the geometry or creating a defect can help the engineering of the nanostructured properties, such as increasing the frequency sensitivity of graphene nanosheets as a mass sensor by changing the geometry of the structure in a triangular shape and also by creating a vacancy or making nanodiodes in a triangular shape, which restricts the flow of heat in one direction and expands it in another direction. Then, the mechanical properties of the triangular geometry of graphene nanosheets have an excellent value for future devices. The results of the molecular dynamics study can illustrate the mechanical properties of graphene sheets well, which is particularly important. In this study, using molecular dynamics (MD) simulation, the bending stiffness of triangular graphene sheets was investigated to present a broader view of engineering applications of graphene sheets. Analyzing stress-displacement results of triangular graphene sheets in both zigzag and armchair directions under bending load reveals the effect of the directions of sheets on their bending stiffness. Also, comparing the bending stiffness of pristine and defective sheets showed that bending stiffness was decreased when an atom was removed from the middle of a sheet and made a single vacancy defected sheet. Obtained results suggest that triangular graphene nanosheets with higher bending stiffness, compared to rectangular sheets with the same number of atoms, are better for applications requiring higher bending properties, such as nanoelectromechanical devices. The reported results of this work provide an overall viewpoint concerning the geometry and defect effects on the graphene nanosheets' mechanical properties. The bending stiffness of triangular sheets was 20 and 10 times that of intrinsic and defective rectangular sheets, respectively.