Analysis of the small-angle intensity scattered by a porous and granular medium

Using X-ray scattering over a large range of scattering vectors, it is shown how to measure both the pore volume fraction and pore specific surface of an assembly of porous grains forming a powder. Depending on the presence or not of solvent in the inner pores and in the intergranular media, the scattered signal per unit volume of solid or per unit volume of grain are introduced, which allow a complete analysis even when the thickness of the layer and its compactness are unknown. The method is applied to three different systems presenting a well defined Porod regime at large scattering vector.