Zigzag and spiral configurations for fullerenes in carbon nanotubes

Abstract

The success or otherwise of nanoscale devices hinges on a correct understanding of the physical effects at this scale. Research in nanotechnology is predominantly through either experimentation using electron and atomic force microscopy or through large-scale computation using molecular dynamics simulation. In this paper, we employ elementary mechanical principles and classical modelling procedures to investigate the packing of C60 fullerene chains inside a single-walled carbon nanotube by utilizing the Lennard–Jones potential function and the continuum approximation. Such assemblies are often referred to as nanopeapods. We examine both zigzag and spiral chain configurations inside (10, 10), (16, 16) and (20, 20) carbon nanotubes and we obtain analytical expressions in terms of hypergeometric functions for the potential energy for such configurations. We find that for a (10, 10) tube, the C60 fullerene chain is formed linearly along the tube axis. In the case of both (16, 16) and (20, 20) tubes, both zigzag and spiral configurations are more clearly evident along the tube. In particular, the resulting pattern obtained for the zigzag chain is entirely consistent with a specific angular spacing for the spiral pattern.