Molecular dynamics simulations of ion transport through carbon nanotubes. I. Influence of geometry, ion specificity, and many-body interactions.

Extensive molecular dynamics simulations of the flow of aqueous NaCl and NaI solutions through carbon nanotubes are presented, evidencing the dependence of diverse transport features on the solute specificity, the nanotube geometry, and the various atomic models employed, including polarizability. The simulated properties are in agreement with published results, indicating that ion translocation sets in only for nanotubes with chiralities higher than (7,7), and extend the explanation of the mechanisms governing ion transport to larger chiralities. The interpretation of the various dynamic quantities is developed in close connection with the structural details of the solution and the energy barriers the solute components have to overcome. Also, the role and relevance of water and ion polarizabilities are discussed in detail.