STRUCTURAL MODELS OF DENSE GELS

The structural models of gels typically reported concentrate either on the ''solid space'' or the ''pore space'' of the system. The models d escribed in this paper present a connection between grain and pore spa ces, applicable to dense gels with uniform particulate microstructure. The gel structure is depicted as a hierarchy at several levels by mea ns of models built up using the Monte-Carlo technique, on the basis of random close packing (RCP) premises. The pore volume distributions ar e calculated from the largest sphere radius inscribed within the inter stices. These distributions are compared to the pore volume distributi ons of various RCP classic models and to the pore volume distributions of a series of xerogels measured by means of the Brunauer-Emmett-Tell er method. Data on the pore volumes associated with different hierarch ical levels (e.g., micro-, meso-, or macropores), the local density of the i-th aggregation level and packing of the successive levels are o btained.