Conductivity and permittivity of dispersed systems with penetrable particle-host interphase

Abstract

A model for the study of the effective quasistatic conductivity and permittivity of dispersed systems with particlehost interphase, within which many-particle polarization and correlation contributions are effectively incorporated, is presented. The structure of the system's components, including the interphase, is taken into account through modelling their low-frequency complex permittivity profiles. The model describes, among other things, a percolation-type behavior of the effective conductivity, accompanied by a considerable increase in the real part of the effective complex permittivity. The percolation threshold location is determined mainly by the thickness of the interphase. The "double" percolation effect is predicted. The results are contrasted with experiment.

On applicability of differential mixing rules for statistically homogeneous and isotropic dispersions

“…is obtained. Actually, this is the differential form of (5). It is convenient to use (17) to derive new low-and highconcentration modifications of the ABM rules.…”

“…A big variety of analytical methods and approaches have been developed to study electrophysical characteristics of disperse systems and mixtures [1][2][3][4][5]. However, it is often unclear which one is applicable to a given system [1,[6][7][8].…”

“…The working model is based on the compact groups approach (CGA) [5,[28][29][30]. The 'compact groups' are macroscopic regions in a system with typical linear sizes L that are much smaller than the wavelength of probing field λ in the system: L = λ.…”

“…The validity of the approach was demonstrated in [34] by contrasting its results with existing rigorous analytic results and computer simulations for dispersions of hard dielectric spheres with power-law permittivity profiles, and by processing experimental data on the effective dielectric response of nonconducting polymer-ceramic composites. Earlier, the CGA was efficiently applied to dispersions of particles with complex permittivities to describe electric percolation phenomena in composites of core-shell particles [5], two-step electrical percolation in nematic liquid crystals filled with multiwalled carbon nanotubes [35], and effective parameters of suspensions of nanosized insulating particles [36]. Finally, the idea of compact groups was also used by Sushko to evaluate the effects of multiple short-range reemissions between particles on the mean free path and the transport mean free path of photons in concentrated suspensions [37] and to discover the 1.5 molecular light scattering in fluids near the critical point [38,39]; the results were supported by extensive experimental data.…”

Effect of inhomogeneity of the interphase layer on the conductivity percolation behavior of insulator/conductor dispersions

“…В роботі [9] побудовано багаточастинкову теорію квазістатичного електричного відгуку невпорядкованих систем з електрично однорідним проникним міжфазним шаром для систем типу ізолятор-провідник (слабко провідна матриця, високопровідні частинки, оболонки з проміжною провідністю) та показана її ефективність для опису провідності та діелектричної проникності таких систем поблизу порогу перколяції. Зокрема, було показано, що поріг перколяції c с залежить тільки від геометричних розмірів оболонки, а критичні індекси s та t можуть мати широкий спектр значень, які залежать від значень провідностей компонентів системи та концентраційних проміжків, на яких вони визначаються.…”