Calculation of Gibbs hydration energy with the ion-dielectric sphere model

Abstract

The Gibbs energy of hydration of gaseous ions of-1 to +4 charge is calculated on the basis of the exact electrostatic solution for the interaction energy of an ion and groups of dielectric spheres. Dispersion energies were added. The average error of the method is 2%. The dielectric constant of the spheres is assumed to be described by Booth's field-dependent version of Kirkwood's theory. The energetic contributions of successive layers of water are obtained by demanding a self-consistent dielectric constant at each shell of water. The results confirm that 78-90% of the hydration energy, depending on the ion, involves water in the inner layer. The accuracy of the Born expression for solvated complex ions, M(H20)"+',~, is in doubt. Inner-layer hydration numbers ranging from 4 to 12 were obtained.

Role of Ion–Phospholipid Interactions in Zwitterionic Phospholipid Bilayer Ion Permeation

“…In this model of translocation, also referred to as the solubility–diffusion model, the ion crosses the hydrophobic core in a desolvated state without causing any membrane distortion . As the desolvation energy of K + is lower than that for Na + , − the former would traverse the hydrophobic core of the membrane more readily, resulting in larger membrane conduction for K + , as reported (Figure .). This model of translocation cannot, however, explain the reduction in membrane conduction reported with Na + at concentrations <5 mM.…”

Facile simulation of carbon with wide pore size distribution for electric double-layer capacitance based on Helmholtz models

“…Previous studies showed that the affinities between the ions and solvent molecules are ranked as aqueous-H 2 SO 4 > aqueous-KOH > TEABF 4 / AN. 61,64,65 The stronger the affinity, the smaller the interfacial distance is for the stabilization of the naked ions in micropores. The strong ion-solvent affinity of the aqueous H 2 SO 4 solution indicates a high concentration of solvent molecules within the interfacial d eff zone, which accounts for the large dielectric constant and therefore the high C/S values for carbons immersed in aqueous H 2 SO 4 .…”

A review of molecular modelling of electric double layer capacitors

“…[TEA] + [BF 4 ] À exhibited much weaker solvation than other inorganic ions in aqueous solutions. 122 Additionally, the AN molecules in the solvation shell of both ions showed weak packing and orientational ordering. The EDL structure at neutral electrodes exhibited strong solvent layering and orientational ordering as well as alternating layers of counter-ions and co-ions, a feature that had not previously been observed.…”