scholarly journals An Empirical Relation for the Evaluation of the Dielectric Relaxation Time of Certain Polar Liquids Using a Single Microwave Frequency

1974 ◽  
Vol 27 (1) ◽  
pp. 87 ◽  
Author(s):  
BS Sarma ◽  
V Venkateswara Rao
Keyword(s):  
Experimental Data ◽  
Relaxation Time ◽  
Dielectric Relaxation ◽  
Concentration Factor ◽  
Empirical Relation ◽  
Microwave Frequency ◽  
Dielectric Constants ◽  
Dielectric Relaxation Time ◽  
Polar Liquids

An empirical relation is proposed for the determination of the dielectric relaxation time .. of polar liquids with nearly spherical molecules from measurements of the dielectric constants at a single microwave frequency. The relation is obtained by introducing a concentration factor as a parameter in the expression for .. derived by Eyring et al. (1941). Its validity for suitable polar liquids is demonstrated by comparison of results with previously reported values. Thermodynamic parameters for a number of liquids at various concentrations have also been evaluated from experimental data using the relation.

Correlation between the electron solvation time and the solvent dielectric relaxation times τ2 and τL1 in liquid alcohols and water: towards a universal concept of electron solvation?

1997 ◽  
Vol 75 (10) ◽  
pp. 1310-1314 ◽  
Author(s):  
Jean-Paul Jay-Gerin
Keyword(s):  
Relaxation Time ◽  
Simple Model ◽  
Dielectric Relaxation ◽  
Hybrid Model ◽  
Relaxation Times ◽  
Close Similarity ◽  
Dielectric Relaxation Time ◽  
Polar Liquids ◽  
Electron Solvation ◽  
Linear Alcohols

A simple model of electron solvation in polar liquids is presented, in which we attempt to link the electron solvation time τs to τ2, the time for reorientation of monomeric molecules, and to τL1, the longitudinal dielectric relaxation time of the solvent. It is shown that this model, which is suggested by the so-called hybrid model of electron solvation previously described for methanol, can satisfactorily account for electron solvation in all polar liquids, including linear alcohols (methanol to decanol), 1,2-ethanediol, H2O, and D2O, for which data are available from the literature. A close similarity is indeed obtained between our calculated values of τs and those measured experimentally. The observation of such a correlation supports a universal concept of electron solvation. Keywords: polar liquids, electron solvation time, solvent dielectric relaxation times, universal concept of electron solvation.

Dielectric relaxation, viscosity and freezing

1957 ◽  
Vol 240 (1220) ◽  
pp. 101-107 ◽  
Keyword(s):  
Dielectric Constant ◽  
Relaxation Time ◽  
Solid State ◽  
Dielectric Relaxation ◽  
Simple Relation ◽  
Experimental Results ◽  
Organic Liquids ◽  
Dielectric Relaxation Time ◽  
Polar Liquids ◽  
Molecular Radius

It is shown that polar liquids may be divided into two classes according to whether or not the rotation of the dipoles is prevented by solidification. For liquids belonging to the first class, and having rigid molecules, an equation similar to Debye’s can be used to relate the dielectric relaxation time and the viscosity. This equation does not involve the ‘molecular radius’ which has always made the interpretation of Debye’s equation uncertain, and it can, in consequence, be used to determine from the experimental results how the ratio of the microscopic to the macroscopic relaxation time ( ז/ז ') depends on the static dielectric con­stant. The theory has been applied to a number of organic liquids of rigid molecular struc­ture, and indicates that the dependence of ז/ז ' on the dielectric constant is best expressed by Powles’s equation ז/ז ' = (2∊ 0 + ∊ ∞ )/3∊ 0 . For liquids belonging to the second class no simple relation between dielectric relaxation time and viscosity can be expected, but it may be possible to relate the relaxation time in some way to the transition which occurs in the solid state, in which the freedom of dipole rotation is lost.

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