Energetics and stability of C60 molecules encapsulated in carbon nanotubes

Abstract

An energetic analysis was performed to study the interactions of C60 molecules encapsulated in carbon nanotubes. Both direct interaction between C60 molecules through van der Waals forces and indirect interaction between encapsulated C60 molecules through the elastic deformation of their host carbon nanotubes were considered. For C60s encapsulated in a (9, 9) nanotube, the indirect interaction dominates and a relatively large energy barrier exists for the formation of a uniform, stable, one-dimensional (1-D) C60 array. For a (10, 10) nanotube, the indirect interaction leads to a small energy barrier to form a 1-D C60 array, while for a (11, 11) nanotube the influence of the indirect interaction is negligible. Molecular dynamics simulations were performed to confirm the present energetic analysis, suggesting that the indirect interaction between encapsulated molecules/particles through the elastic deformation of their host nanotubes may affect the stability of nanotube-based structures. © 2008 Elsevier Ltd. All rights reserved.