Application static permittivities

However, the latter formula is not more applicable, if xlaa is rather long and/ or Cm is rather high, so that the zero-frequency ionic contribution Aefon(0) to permittivity is noticeable in comparison with the static permittivity es of the solution. We note that the Kirkwood correlation factor g is used for calculation of the component p in Eq. (387). Thus, even in our additivity approximation the solvent permittivity )jip is determined in this case by concentrations of both solution components. This complication leads to a new self-consistent calculation scheme. 

Solvent permittivity — is an index of the ability of a solvent to attenuate the transmission of an electrostatic force. This quantity is also called the -> dielectric constant. -> permittivity decreases with field frequency. Static (related to infinite frequency) and optical op (related to optical frequencies) permittivities are used in numerous models evaluating the solvation of ions in polar solvents under both static and dynamic conditions. Usually the refractive index n is used instead of op (n2 = eop), as these quantities are available for the majority of solvents. The theory of permittivity was first proposed by Debye [i]. Systematic description of further development can be found in the monograph of Frohlich [ii]. Various aspects of application to reactions in polar media and solution properties, as well as tabulated values can be found in Fawcetts textbook [iii]. 

The nature of the solvent is represented in the Born equation only by the static dielectric permittivity e, which includes all types of polarization. The Born assumption on the structureless nature of the solvent may be only approximately fulfilled in the case when the ion is cdhsiderably larger than the solvent molecules. The problem of ion size and the applicability of the dielectric model has been discussed by Evans et al. [23]. 

As far as measurements are concerned the perturbation method of Buravov and Shchegolev provides reliable results not only in the quasi-static region but practically at least one order of magnitude above the kb =>f limit. Moreover, for the spheroid of arbitrary complex permittivity we have found the universal perturbation relation valid for arbitrary wavelength inside the sample. This generalized approach not only covers various approximations used until now, but also strictly determines the limits of their applicability. ... 

The static dielectric permittivity is an important parameter that characterises the response of a medium to the application of an electric field. Its value is determined by the distribution of the electric charges in molecules (polar and non-polar compounds) as well as by the intermolecular interactions (for example anisotropy of the medium and intermolecular correlations). In nematics the dielectric permittivity is a tensorial quantity. The value and the sign of the dielectric anisotropy play an important role in the application of nematics in display technologies. 

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