Fullerene-to-MWCNT Structural Evolution Synthesized by Arc Discharge Plasma

Muhammad Roslan,Kashif Chaudary,Jalil Ali,Muhamad Jofri,Azam Mohamad,Misbahul Abd Rahman

doi:10.3390/c4040058

Abstract

The growth of multi-walled carbon nanotubes (MWCNTs) has been extensively studied using electron microscopy. The ex situ structural behavior was examined to investigate the growth of the MWCNTs under different environments and pressures using electron microscopy. The arc discharge plasma technique was applied to synthesize the MWCNTs by evaporating carbon through the arc plasma between two cylindrical graphite rods, with a background pressure of 10−2 to 102 mbar, inside a vacuum chamber under different ambient environments. The results showed that long MWCNT structures were successfully grown. We suggest that the mechanism involves: (i) fullerene formation; (ii) the elongation of fullerenes; and (iii) the growth of MWCNTs. Agglomeration with other structures then forms MWCNT bundles. We note that the pressure and environment in the vacuum chamber can affect the structure of the MWCNTs.

Highlights

Carbon nanomaterials will have numerous applications in future technologies due to their extraordinary electrical, thermal, and mechanical properties, which make carbon nanomaterials one of the most commonly studied materials
It is important to understand the growth mechanism of carbon nanotubes and their structural behavior in order to exploit the full potential of multi-walled carbon nanotubes (MWCNTs) based on the electron microscopy technique, because the large clusters evolve from the building block of the small cluster
The growth of MWCNTs using the arc discharge plasma method is strongly dependent on the ambient environment, as the residual gas significantly contributes to the kinetics of carbon ions

Summary

Introduction

Carbon nanomaterials will have numerous applications in future technologies due to their extraordinary electrical, thermal, and mechanical properties, which make carbon nanomaterials one of the most commonly studied materials. Arc discharge plasma was the first method to synthesis the carbon nanotube [4]. This method applies an electrical breakdown between two graphite electrodes inside a vacuum chamber that is normally filled with hydrocarbon or inert gases. Arc discharge plasma is one of the most effective techniques for growing carbon nanotubes and other materials, including graphene [5,6], as it provides a fast process with a large-scale production of MWCNTs [7]. It is important to understand the growth mechanism of carbon nanotubes and their structural behavior in order to exploit the full potential of MWCNTs based on the electron microscopy technique, because the large clusters evolve from the building block of the small cluster

Formation of Long MWCNT Structures

Growth Mechanism of MWCNT Structures

Materials and Methods

Conclusions