Ion Distribution in a 3 nm in Diameter Nanopore

The influence of surface charge density and applied bias on the ion distribution of a 3 nm in diameter nanofluidic pore was investigated using molecular dynamics simulations. Our simulation results indicate that the radial ion distribution profile with different surface charge density under applied bias is similar to that without applied bias except that the first peak of the ion distribution appears to become small and far away from the solid wall under applied bias. This unusual observation is attributed to the principle that with a higher applied bias, ions have more kinetic energy and relocate to an area farther away from the wall. Considering that ion mobility along a radius is asymmetric, it is can be concluded, that by changing the ion radial distribution, the applied bias will cause a change in ion selectivity in a nanopore.