Etude du gonflement des vermiculites-ornithine en solution saline par analyse de la diffusion des rayons X aux petits angles. Méthode d'interprétation et recherche des paramètres d'ordre

A method of interpretation is presented for the small-angle scattering patterns of vermiculite-ornithine gels. The method has been applied to the results obtained from a vermiculite from Malawi. The distribution of spacings between parallel first-neighbour silicate layers can be described by three order parameters, whose values are found by analysing the experimental modulation functions. The variation of these order parameters with the salt concentration of the suspension should allow one to specify the swelling process as well as the relationship between the crystal chemical properties of the silicate and its behaviour as a colloid.