A Molecular Dynamics Study on the Absorption of Ions Into Carbon Nanotubes

The ability of ions to be selectively absorbed into nano-pores is important for a wide range of industrial and biological processes. To make practical use of such ionic selectivity, a molecular-level understanding of the dynamics is required, so that conditions can be tailored and optimised as required. This is especially the case when the ions being separated are very similar. We have therefore conducted molecular dynamics simulations in order to study the selective absorption of sodium and potassium ions into a nano-scale pore. We show how ion hydration and the presence of a negative ion lead to alternative selectivity depending on the size of the pore.