We present the results from an experimental study of the permittivity and the loss tangent of Chasov-Yarsk clay as functions of the moisture content and wavelengths. We describe the installation used to study the changes in capacitance during the course of drying the material.There is considerable interest ininvestigating the electrophysical properties of moistenedChasov-Yarsk clay as a typical colloidal capillary-p0rous material in connection with a study of the mechanisms of dehydration and drying, as well as for the development of electrical methods of determining the moisture content of disperse systems.To calculate the power P of the energy scattered in the material as it is heated in a high-frequency electric field E P = 5.55E~fe ' tg~. 10 ~7 w, we must know the magnitude of the permittivity e' and the loss tangent tan~3 of the material with a specific moisture content w at various frequencies f.This clay was cleansed of mechanical impurities by sedimentation iil distilled v~ater; it was dried, ground in a porcelain mortar, and passed through a sieve with a mesh of d = 0.25 ram. The prepared specimens were dried for 12 h 120~The moisure content of the dried specimen was assUmed to be zero.The water-retention properties of the Chasov-Yarsk clay have been studied rather well by various mutually independent methods [1]. We performed a control check on the water-retention properties of this clay, using such methods as the heats of wetting [2], the Dumanskii indicator [3] involving the use of an ITR-1 interferometer, sorption and desorption isotherms, and thermograms of isothermal drying [4,5]. All of the tests were carried out at 25~The experimental data are given in the table and agree with the literature data of [1,3].The electrophysical properties Chasov-Yarsk clay, in connection with the moisture content, were studied in a wavelength range from 6000 to 3 m with Q-meters, in accordance with an earlier developed method [6]. Figure la shows the experimental data in the form of curves for the functlonseT(w) and tan~(w) for wavelengths of 6000, 400, 40, and 20 m.In the region of moisture contents corresponding to monomoleeular adsorption, we find an approximately linear relationship between the permittivity and the moisture content. For large moisture contents we subsequently note a substantial increase in the permittivity, which is all the more pronounced for the longer waves. The latter circumstance indicates the dispersion of the system's permittivity.With low water contents the magnitude of tan 5 for all wavelengths increases markedly; we then note a linear relationship between tan ~ and w. For h = 6000 m when w ~ 3.5% we find a transition from the linear segment to a steeper slope for the function tan 5(w). This is apparently associated with the fact that for small wavelengths relaxation polarization is characteristic for the molecules of the subsequent adsorption layers of water which are not as strongly bound as the monomolecular layer.Gor'kii Pedagogical Institute, Kiev.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.