title: Dielectric constant of ionic solutions: a field-theory approach.
abstract: We study the variation of the dielectric response of a dielectric liquid (e.g. water) when a salt is added to the solution. Employing field-theoretical methods, we expand the Gibbs free energy to first order in a loop expansion and calculate self-consistently the dielectric constant. We predict analytically the dielectric decrement which depends on the ionic strength in a complex way. Furthermore, a qualitative description of the hydration shell is found and is characterized by a single length scale. Our prediction fits rather well a large range of concentrations for different salts using only one fit parameter related to the size of ions and dipoles.
authors.affiliation: Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel.
authors.forename: Amir
authors.initials: A
authors.lastname: Levy
authors.forename: David
authors.initials: D
authors.lastname: Andelman
authors.forename: Henri
authors.initials: H
authors.lastname: Orland