A model for the pore size distribution in random and isotropic mixtures of cylindrical fibres and circular disks

A model for the distribution of pore sizes in systems of randomly distributed cylindrical fibers and circular disks is developed that derives from simple excluded-volume considerations. The dimensions of the particles with finite hard cores are mapped onto those of a hypothetical system of fully penetrable objects in a manner that preserves the overall core-occupied volume fraction and specific surface area. This mapping enables us to obtain estimates for the pore size distribution, and for the first and second moments of the pore sizes, as functions of the particle volume fraction and mixture composition in terms of closed-form, analytical expressions. (paper)