The movement of ions across nanopores, or nanoporous membranes, is the elementary process at the heart of most transport issues in biological membranes, or in separation, desalination or osmotic energy technologies. The problem is a priori simple in terms of ingredients, but electrostatic interaction is of considerable complexity, as it induces a profusion of coupling phenomena associated with varied energies and spatial scales : Bjerrum, Debye, Dukhin, Gouy-Chapmann lengths. Interactions are also considerably modified by confinement, and even by the electronic properties of the confining material. The very entry of ions into pores remains a complex phenomenon involving dielectric, electrostatic (Donnan) and even quantum effects.
We will provide an overview of these mechanisms, which play a key role in ion selectivity processes, as well as diffusive and field transport (electric or otherwise).
