The frequency-dependent conductivity of a saturated solution of ZnBr2 in water: A molecular dynamics simulation

Abstract

The first part of this paper reviews the theory of the calculation of the frequency-dependent dielectric properties (i.e., conductivity and dielectric constant) of ionic solutions from computer simulations. Based on a 2.2-ns molecular dynamics simulation, the second part presents a detailed analysis of the various contributions to the frequency-dependent conductivity of a saturated solution of ZnBr2 in water. We find evidence for two separate relaxation channels in the frequency-dependent conductivity, and a very low value for the static (i.e., zero frequency) conductivity, which is consistent with the high degree of ion association and the prevalence of electrically neutral ion clusters that we observe in this system.

On the collective network of ionic liquid/water mixtures. II. Decomposition and interpretation of dielectric spectra

“…It has been shown, however, that for perfect Ewald conditions ͑tinfoil boundaries͒ this net Maxwell field E equals the applied external field E 0 . 46 Therefore, both fields may be used synonymously in this particular case. For not too strong electric fields, the dependence of ͗M tot ͘ E on E is linear,…”

Electric Double Layer at the Rutile (110) Surface. 2. Adsorption of Ions from Molecular Dynamics and X-ray Experiments

“…This is achieved by choosing very small potential depth of the refitted potential; the parameter σ is then given by a condition that the product 4 σ 12 equals the coefficient A of the original potential. In accord with the combining rule given in ref 15, we have used the geometric mean for both σ ij and ij when zinc ion was involved.…”

“…For zinc we used the same potential as given in ref 15, i.e., purely repulsive potential, which was given in the form U ij ) A ij /r ij , 12 with combining rule A ij ) A i ′A j ′ and A Zn ′ ) 0.9716 × 10 -4 kJ 1/2 mol -1/2 nm 6 . To be able to combine this potential with LJ potentials of other ions, we have refitted the original zinc potential to a LJ form with a negligible attractive part.…”

Static dielectric constant of aqueous electrolyte solutions: Is there any dynamic contribution?

“…Over the past two decades, several studies showing the presence 2-7 and also absence [8][9][10][11] of the dynamic contribution have been reported and the issue has remained an open question. In this Communication, we show that there can be a finite dynamic contribution to the static dielectric constant of aqueous electrolyte solutions, although the magnitude of such dynamic contribution is negligibly small compared to the corresponding equilibrium contribution.…”