Monte Carlo simulation of the double layer at an electrode including the effect of a dielectric boundary

Abstract

Monte Carlo values of the density profiles and related properties of the double layer formed by an electrolyte near a charged electrode are reported for the cases where the electrode has a dielectric coefficient greater, equal, and smaller than that of the electrolyte that causes a surface polarization that can be represented by electrostatic images. As expected, compared to the case where there is no dielectric boundary the ions near the electrode are attracted or repelled by the electrode if the dielectric coefficient is greater or smaller, respectively, than that of the electrolyte. This effect is most pronounced near the electrode and is stronger for 2:2 electrolytes than for 1:1 electrolytes. For both monovalent and divalent ions the effect of the dielectric boundary is stronger at low concentrations.

Keywords:

• Monte Carlo simulation
• Dielectric boundary
• Density profiles
• Electrolyte
• Double layer

Acknowledgements

The authors are grateful for the advice of David Busath and Dezso Boda and to Dezso Boda for kindly providing us with his Monte Carlo code. MA is grateful for the financial support of a Roland K. Robbins Graduate Research Fellowship. A generous allotment of computer time by the Ira and Marylou Fulton Supercomputing Center at BYU is acknowledged with thanks.