D. Boda et al., MONTE-CARLO SIMULATION OF AN ION-DIPOLE MIXTURE AS A MODEL OF AN ELECTRICAL DOUBLE-LAYER, The Journal of chemical physics, 109(17), 1998, pp. 7362-7371
Canonical Monte Carlo simulations were performed for a nonprimitive mo
del of an electrical double layer. The ions and the solvent molecules
are modeled as charged and dipolar hard spheres, respectively, while t
he electrode as a hard, impenetrable wall carrying uniform surface cha
rge. We found that the ion-dipole model gives a reasonable description
of the double layer for partially charged ions with small to moderate
dipole moments, or equivalently for an ''effective'' dielectric const
ant. Density, polarization and mean electrostatic potential profiles a
re reported. Strong layering structure, and at higher charges, charge
inversion in the second layer were found. With appropriate choices of
charge and solvent parameters, states corresponding to the primitive o
r the solvent primitive model can be produced, and the results agreed
well with literature data. At higher effective charges and dipole mome
nts, the dipolar solvent has difficulties in preventing the ions from
clustering. More realistic models of water and other solvents are nece
ssary to study the double layer. (C) 1998 American Institute of Physic
s. [S0021-9606(98)51341-4].