Open AccessKinetic polarization deficiency in electrolyte solutions.
Author(s) -
John H. Hubbard,
Lars Onsager,
W M van Beek,
M. Mandel
Publication year - 1977
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.74.2.401
Subject(s) - dielectric , electrolyte , dipole , polarization (electrochemistry) , electric field , chemistry , ion , kinetic energy , permittivity , relaxation (psychology) , solvent , chemical physics , cole–cole equation , thermodynamics , nuclear magnetic resonance , materials science , physics , classical mechanics , organic chemistry , electrode , quantum mechanics , psychology , social psychology , optoelectronics
The prediction and experimental confirmation of a previously unsuspected kinetic effect occurring in electrolyte solutions are presented herein. Kinetic polarization deficiency may be described as a reduction, with respect to the pure solvent, in the static permittivity of the solution; the decrement in epsilon0 is shown to be proportional to the product of the dielectric relaxation time of the solvent and the low frequency conductivity of the solution. The kinetic ion-solvent interaction affects the capacitive admittance in two closely related ways: as an ion migrates, the surrounding volume elements of the liquid tend to rotate according to the laws of hydrodynamics, and although dielectric relaxation tends to restore an equilibrium polarization appropriate to the local electric field, this adjustment is not instantaneous; rather it lags behind by the dielectric relaxation time. Conversely, the force that an external field exerts on an ion does not develop its full strength instantly because the ion is driven partly by the external field and partly by the polarization that develops in response to the applied field, the polarization field evolving with a time constant that is the relaxation time for the orientation of solvent dipoles.