Competition between Born solvation, dielectric exclusion, and Coulomb attraction in spherical nanopores

Abstract

The recent measurement of a very low dielectric constant, ϵ, of water confined in nanometric slit pores leads us to reconsider the physical basis of ion partitioning into nanopores. For confined ions in chemical equilibrium with a bulk of dielectric constant ϵb>ϵ, three physical mechanisms, at the origin of ion exclusion in nanopores, are expected to be modified due to this dielectric mismatch: dielectric exclusion at the water-pore interface (with membrane dielectric constant, ϵm