Surface area, geometrical and configurational effects on permittivity of porous media

Dielectric permittivity measurements in high surface area porous media are subject to a number of influences, including water binding effects which often lead to erroneous water content estimates. Errors are primarily due to the large disparity between the permittivity of bound (5) and free water (80). Water bound to solid surfaces exhibits a 'thermodielectric' effect involving temperature-dependent volume exchange between these two water phases. Particle shape and phase configuration may also reduce permittivities of porous mixtures in addition to the influence of bound water. Modeled predictions of these effects are presented and discussed and are based on a three-phase dielectric mixing model. (C) 2002 Elsevier Science B.V. All rights reserved.