Two-phase tension of a carbon nanotube

Abstract

Heterostructures consisting of new two-dimensional nanomaterials may possess non-trivial physical and mechanical properties, promising for many applications. It is interesting that in some cases it is possible to create heterostructures simultaneously consisting of weakly and strongly stretched domains having the same chemical composition, as have been witnessed earlier for some polymer chains, DNA, and intermetallic nanofibres that demonstrate the effect of two-phase stretching. These materials with relatively large tensile forces tend to split into domains with less and greater tensile deformation. Within the two-phase region of deformation, the average deformation of the sample increases with a constant tensile force, with the growth of a domain with a higher strain due to a domain with a lower strain. In this paper, the two-phase stretching of carbon nanotubes has been studied by means of molecular dynamics simulation. It has been established that the load-deflection curves during axial tension exhibit hysteresis-like behavior due to energy dissipation during nucleation and motion of domain walls. It is shown that in the two-phase tension regime, a carbon nanotube is a special case of a heterostructure, the properties of which can be controlled by changing the size of the domains of each phase by applying elastic deformation.