Snapshots of the Fragmentation for C70@Single-Walled Carbon Nanotube: Tight-Binding Molecular Dynamics Simulations.

Ji Young Lee,Jung Chul Sur,Jong Woan Choi,Eiji Osawa,Kee Hag Lee,Changhoon Lee

doi:10.3390/ijms22083929

Abstract

In previously reported experimental studies, a yield of double-walled carbon nanotubes (DWCNTs) at C70@Single-walled carbon nanotubes (SWCNTs) is higher than C60@SWCNTs due to the higher sensitivity to photolysis of the former. From the perspective of pyrolysis dynamics, we would like to understand whether C70@SWCNT is more sensitive to thermal decomposition than C60@SWCNT, and the starting point of DWCNT formation, which can be obtained through the decomposition fragmentation of the nanopeapods, which appears in the early stages. We have studied the fragmentation of C70@SWCNT nanopeapods, using molecular dynamics simulations together with the empirical tight-binding total energy calculation method. We got the snapshots of the fragmentation structure of carbon nano-peapods (CNPs) composed of SWCNT and C70 fullerene molecules and the geometric spatial positioning structure of C70 within the SWCNT as a function of dynamics time (for 2 picoseconds) at the temperatures of 4000 K, 5000 K, and 6000 K. In conclusion, the scenario in which C70@SWCNT transforms to a DWCNT would be followed by the fragmentation of C70, after C70, and the SWCNT have been chemically bonding in the early stages. The relative stability of fullerenes in CNPs could be reversed, compared to the ranking of the relative stability of the encapsulated molecules themselves.

Highlights

The formation of a closed C fullerene by creating curvature through the fusion of 12 pentagon rings of carbon has been the special topic of several studies [1]
Using the internal space of the SWCNT as a nanometer-scale reaction chamber, double-walled carbon nanotubes (DWCNTs) forming secondary tubes inside the SWCNT were observed, which confirmed that the temperature excitation can be used to overcome the activation barrier for the inner tube formation [9]
It was claimed that the conversion of C70@SWCNT into double-walled carbon nanotubes was more efficient than the corresponding conversion of C60@SWCNT [7] and (C60)@SWCNT due to the higher sensitivity to photolysis of the former [12]

Summary

Introduction

The formation of a closed C fullerene by creating curvature through the fusion of 12 pentagon rings of carbon has been the special topic of several studies [1]. One of the most prominent features of nanocarbons (e.g., fullerenes, carbon nanotubes, and graphene) is their ability to encapsulate atoms, ions, molecules, molecular ions, nanowires, or nanoribbons in empty spaces within their structures [4]. Using the internal space of the SWCNT as a nanometer-scale reaction chamber, double-walled carbon nanotubes (DWCNTs) forming secondary tubes inside the SWCNT were observed, which confirmed that the temperature excitation can be used to overcome the activation barrier for the inner tube formation [9].

Results

Conclusion