The Influence of Liquid Structure on Interfacial Ion Distributions
Prof. Mark SCHLOSSMAN
Department of Chemical Engineering, University of Illinois Chicago
Jeudi 21/06/2007, 11:00
NIMBE Bât 125, p.157, CEA-Saclay
Mean field theories of ion distributions, such as the Gouy-Chapman theory
that describes the distribution near a charged planar surface, ignore the
molecular-scale structure in the liquid solution. The predictions of the
Gouy-Chapman theory vary substantially from our x-ray reflectivity
measurements of the interface between two electrolyte solutions. These
structural measurements are described well by ion distributions predicted
by a version of the Poisson-Boltzmann equation that explicitly includes a
free energy profile for ion transfer across the interface when this
profile is described by a simple analytic form or by a potential of mean
force calculated from molecular dynamics simulations. These x-ray
measurements from the liquid-liquid interface provide evidence for the
importance of interfacial liquid structure in determining interfacial ion
distributions.