Molecular dynamics simulation of zigzag single-walled carbon nanotube closing mechanisms

Abstract

Molecular dynamics (MD) simulation was used to investigate the closing mechanism of zigzag single-walled carbon nanotubes (SWCNT) at an experimental arc-discharge temperature of 3000 K. The closing mechanism was studied with a variation in the diameter and length of the SWCNT. The (10,0) SWCNT with a diameter of 0.78 nm and a length of 2.13 nm showed a saddle-shaped cap that was caused by a heptagon-octagon pair and a nonagon. When its length was increased three times in, the closing process was observed faster and the closed structure maintained a similar saddle shape, while this resulted from double heptagon-octagon pairs. In the case. of (18,0) SWCNT with a diameter of 1.404 nm, a zipper-like closing mechanism was found and a flat cap was attained. It was also revealed that the longer the length of the (18,0) SWCNT, the slower is the closing process, contrary to the case of (10,0) SWCNT.