Formation of aqueous colloidal dispersions of exfoliated gamma-zirconium phosphate by intercalation of short alkylamines

A good exfoliation of layered gamma-zirconium phosphate in aqueous medium a t room temperature has been obtained by intercalation of short alkylamines such as methyl-, dimethyl- and ethyl-amine. No appreciable exfoliation was observed when butylamine or longer alkylamines were intercalated, while int ermediate behavior was obtained with the intercalation of propylamine. Sinc e a good exfoliation of this layered compound is an essential step for its functionalization by topochemical reactions with phosphonic or phosphinic a cids, the amine intercalation compounds and the various steps of the interc alation processes were investigated in order to obtain information on the m echanism of the exfoliation and a model of this mechanism is proposed. The use of the colloidal dispersion of exfoliated lamellae for the preparation of auto-consistent and flexible membranes as well as thin supported films o f gamma-zirconium phosphate is described.