Molecular dynamics predictions for chemical modification of "nanopeapods" via ion beam deposition

Simulations and experiments have found that at incident energies of 10-80 eV/ion, ion deposition on carbon nanotube bundles leads to covalent bond formation between nanotubes or adjacent tube walls. In this study, classical molecular dynamics simulations are used to study the polyatomic-ion beam deposition on C₆₀-filled carbon nanotubes (nanopeapods). The ion beam consists of 10 CF₃⁺ ions and the incident energy considered is 80 eV/ion. The system consists of a bundle of (10,10) single-walled carbon nanotubes filled with C₆₀ molecules. The forces in the simulation are calculated with the short-ranged many-body, reactive empirical bond-order potential for hydrocarbons and fluorocarbons and long-range Lennard-Jones potentials. The simulations confirm the effectiveness of ion beam deposition in producing covalent cross-links between the carbon nanotubes and the C₆₀ molecules. They also predict the dependence of such modifications on the location of the nanotube within the bundle relative to the ion beam from an atomic-scale point of view. The findings could have important implications for the production of carbon nanotube-based nanocomposites materials and electronic devices.