Characterization of the flow properties in Vycor by combining dynamic and scattering techniques

Complete text of publication follows. Vycor 7930 porous glass was studied by small-angle scattering of neutrons and relative permeability methods. The internal surface of Vycor is fractally rough with a fractal dimension, D 2.5 [1]. Surface fractality influences both the adsorption and the permeability processes. By loading Vycor porous glass with two widely different adsorbates, H2O and CH2Br2, the defractalization process was examined by adsorption in conjunction with small-angle scattering. It was found that the defractalization process is faster with water than with dibromomethane, and that the relative permeability curve is markedly different for a H2O/He system than for CH2Br2/He one. In particular, the presence of water enhances the permeability process resulting in a strong maximum at a p/p0 similar to that of defractalization point [2,3]. It was concluded that the transport properties of a fractal system are affected by surface irregularities and the estimation of the diffusion coefficient is feasible. (author)