Dielectric Properties of Liquid-Impregnated Porous Solids

摘要: Dielectric spectroscopy is a versatile tool that can often be used as non-destructive, indirect way of measuring other important properties (such content crude oil or degree curing resin). The dielectric materials are thus interest in several circumstances and not only for electrical purposes insulation). In this work, the have been studied porous solids, impregnated with liquid. This an encountered system seldom detail due to two intrinsic difficulties: (a) geometry pores complex (b) there may effects interaction between solid fluid at interface. studies both theoretical experimental. I mostly different kinds idealised systems. first type consists sand beads, glued small amounts epoxy. second polypropylene sintered form material. These salty water insulation liquid (a mixture mono- dibenzyl toluenes) which ions added. Although dispersion constituent neglected frequency range used, measurements show relaxations arise "bulk" heterogeneous At high frequencies, so-called Maxwell-Wagner relaxation arises. low another has found. attributed diffusion electrochemical double-layer. For frequencies above low-frequency relaxation, interface conductivity was obtained, increases strength relaxation. dependence on temperature pore studied. Models examined further extended order more general. Grain Consolidation Model found especially versatile. Even if models give simplified picture reality, their predictions fair agreement experimental results. An extension Differential Effective-Medium theory yield good data relaxation. related microgeometry through parameter, L, estimated from permeability.