Theoretical Study of Electrolyte Diffusion through Polarizable Nanopores

Abstract

The diffusion of binary aqueous electrolytes through nanopores with dielectric as well as conductive surface is investigated theoretically on the basis of Space–Charge model. The latter is extended to the case of polarizable nanopore wall. It is shown that the diffusion of ions with different mobilities generates the electric field, which induces non–uniform surface charge in a polarizable nanopore. It results in charge separation inside the pore and leads to a dramatic enhancement of membrane potential in comparison with a non–polarizable nanopore. The calculations are performed for three aqueous electrolytes based on KCl, NaCl, and LiOH. The influence of electrolyte type and concentration difference applied across the pore on the ion transport and membrane potential is discussed and analyzed.