Giant Axial Dielectric Response in Water-Fille Nanotubes an Effective Electrostatic Ion-Ion Interactions from a Tensorial Dielectric Moel

Molecular ynamics simulations in conjunction with effective meium theory are use to investigate ielectric effects in water-fille nanotubes. The resulting effective axial ielectric constant shows a ivergent increase for small nanotube raii that epens on the nanotube length, while the effective raial ielectric constant ecreases significantly for thin nanotubes. By solving Poisson's equation for an anisotropic ielectric meium in cylinrical geometry, we show that the axial ion-ion interaction epens for small separations primarily on the raial ielectric constant, not on the axial one. This means that electrostatic ion-ion interactions in thin water-fille nanotubes are on the linear ielectric level significantly enhance ue to water confinement effects at small separations, while at large separations the outsie meium ominates. If the outsie meium is metallic, then the ion-ion interaction ecays exponentially for large ion separation.