Polarization charge: Theory and applications to aqueous interfaces

Bobo Shi; Mithila V Agnihotri; Si-Han Chen; Richie Black; Sherwin J Singer

doi:10.1063/1.4945760

Polarization charge: Theory and applications to aqueous interfaces

J Chem Phys. 2016 Apr 28;144(16):164702. doi: 10.1063/1.4945760.

Authors

Bobo Shi¹, Mithila V Agnihotri¹, Si-Han Chen², Richie Black², Sherwin J Singer¹

Affiliations

¹ Biophysics Program, Ohio State University, Columbus, Ohio 43210, USA.
² Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio 43210, USA.

PMID: 27131558
DOI: 10.1063/1.4945760

Abstract

When an electric field is applied across an interface, a dielectric will acquire a polarization charge layer, assumed infinitely thin in the theory of macroscopic dielectrics and also in most treatments of electrokinetic phenomena in nanoscale structures. In this work we explore the polarization charge layer in molecular detail. Various formal relations and a linear response theory for the polarization charge are presented. Properties of the polarization charge layer are studied for three aqueous interfaces: air-water, a crystalline silica surface with water, and an amorphous silica surface with water. The polarization charge is calculated from equilibrium simulations via linear response theory and from non-equilibrium simulations, and the results are within statistical error. The polarization charge is found to be distributed within a region whose width is on the order of a nanometer.