| Abstract
| - The transport of methane molecules into several open-ended carbon nanotubes is studied with classical,nonequilibrium molecular dynamics simulations. The forces in the simulations are determined using a reactiveempirical bond order potential for short-ranged interactions and a Lennard-Jones potential for long-rangeinteractions. The simulations show that until the carbon nanotubes are filled with methane molecules up toa specific cutoff molecular density, the molecules move forward and backward along the axis of nanotubesin a “bouncing” motion. This bouncing motion is observed for molecules inside both hydrogen-terminatedand non-hydrogen-terminated opened nanotubes and is caused by a conflict between the molecules' attractiveinteractions with the interior of the nanotube and their response to the molecular density gradient down thelength of the tube. At molecular densities above the cutoff value, the molecules flow into, through, and outof the nanotubes in a linear manner. The effects of molecular density, nanotube diameter, and nanotubehelical symmetry on the results are analyzed.
|
