EFFECTS OF MICROGEOMETRY ON THE PERMITTIVITY OF IMPREGNATED POROUS-MEDIA

We propose a new approximative relation for the low-frequency dielectr ic permittivity of liquid-filled porous materials. In this formulation , effects of microgeometry are included through the so-called Lambda p arameter. Our measurements on salt-water-impregnated artificial sandst ones support the new relation. We also show that the high permittiviti es at low frequencies reported earlier for brine-impregnated sintered glass spheres (Nost et al 1992 Phys. Scr. T 44 67) may be due to effec ts at the solid-liquid interface in the 'bulk' porous material. The la tter results are also in agreement with our proposed relation.