Topochemical processes of intercalation of aluminum hydroxyl polycations into V₂O₅ xerogel films and particles

Intercalation of aluminum hydroxyl polycations from an aqueous solution into V₂O₅ xerogel in the forms of films and particles was studied in order to elucidate topochemical and kinetic processes. Topochemically very inhomogeneous intercalation was observed in the film with a gradual change in interlayer spacing at the reaction front. In contrast, the interlayer spacing of V₂O₅ xerogel particles was increased continuously with increasing reaction time. The apparent rate of intercalation was larger for the finer particles. Distributions of the concentration of Al inward the interfoliar layer were observed for the fine particles. It is concluded that the effective surface area for initiation, and the path length for migration are the main geometrical factors affecting the apparent rate of intercalation, while the mechanism remains invariant.