Abstract
Abstract The influence of sorbed cations and hydration on the a and b dimensions of montmorillonite, has been established by the selected area diffraction technique (S.A.D.) and by X-ray diffraction analysis. Concepts on the bonds and interaction mechanism of aluminosilicate layers with sorbed cations and water molecules (which form hydrate-ionic layers) are discussed. These concepts also indicate the basic stages of the sorption process and the formation of the montmorillonite structure. Assuming that aluminosilicate and hydrate-ionic layers represent a single crystal-chemical structure, the change of configuration of the aluminosilicate layers and dimensions of the montmorillonite lattice are explained.