Polarizable Poisson-Boltzmann equation: The study of polarizability effects on the structure of a double layer

We incorporate ion polarizabilities into the Poisson-Boltzmann equation by modifying the effective dielectric constant and the Boltzmann distribution of ions. The extent of the polarizability effects is controlled by two parameters, gamma(1) and gamma(2); gamma(1) determines the polarization effects in a dilute system and gamma(2) regulates the dependence of the polarizability effects on the concentration of ions. For a polarizable ion in an aqueous solution gamma(1) approximate to 0.01 and the polarizability effects are negligible. The conditions where gamma(1) and/or gamma(2) are large and the polarizability is relevant involve the low dielectric constant media, high surface charge, and/or large ionic concentrations. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3598476]