ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

 Mechanism of the H₂O(g) release during a dehydroxylation of montmorillonite

I. Horváth and Ľ. Gáliková

Institute of Inorganic Chemistry, Slovak Academy of Sciences, 809 34 Bratislava

Abstract: The mechanism of H₂O release during the dehydroxylation of a std. sample of montmorillonite, transformed into Li, Na, K, Cs, Ca, Mg, and Ba monoionic forms, was investigated by an isothermal thermogravimetric method. The dehydroxylation of montmorillonite can be influenced by the kind of the exchangeable ion. The monoionic forms with monovalent exchangeable cations, excepting the Na form, released H₂O according to the mechanism of the 1st-order kinetics. The diffusion of H₂O mols. from phase boundaries was the rate-controlling process for divalent cations and Na⁺ in the interlayer region. It can be assumed that the H₂O transport through the interlayer region into the environment is decisively influenced by the strength of the electrostatic forces between the cation and the neg. charged O atoms of the structure.

Full paper in Portable Document Format: 335a604.pdf

Chemical Papers 33 (5) 604–611 (1979)