Hierarchical deformation of super carbon nanotube under tensile load

Super carbon nanotube (SCNT) is a tubular nano-structure constructed through hierarchically assembling carbon nanotubes (Fig.1), so the performance of SCNT is determined by both the self-structure and structure of armtube CNTs. In this paper, tensile deformation mechanism of SCNT is investigated based on molecular dynamic (MD) simulation. Detailed analyses about structure evolution in different levels of structure are carried out. The results show that major deformation of SCNT transferred from rotation along junctions to elongation of CNTs and finally becomes the local deformation of junctions, which is a top-down transmit procedure from SCNT level to CNT level. These deformations play distinct roles in tensile process due to different stiffness. Rotation results in 50% tensile strain and CNT stretching leads to 70% tensile stress growth. Such hierarchical deformation enables SCNT to possess both considerable strength and super flexibility, which provides a novel guideline for the design of high-performance material.