Mechanism of adsorption of water vapor by muscovite : A model based on adsorption calorimetry
Rakhmatkariev, Gairat (Academy of Sciences of Uzbekistan. Institute of General and Inorganic Chemistry)

Date:	2006
Abstract:	Adsorption isotherms and differential heats of adsorption of water vapor by muscovite were measured at 303 K. The heats of adsorption are stepwise and each step corresponds to the stoichiometric formation of adsorption complexes of HO molecules with K ions, (HO)/K, (n = 1-6), which are located on the basal and lateral (edge) faces. At saturation, the ditrigonal cavities of the basal faces are fully occupied by hexameric clusters. It is suggested that half of the K ions on the basal faces come from neighboring layers by migration under the influence of the adsorbed HO at the initial stage of adsorption. Similar migration of K to the edges was also hypothesized, suggesting that only every second site can be occupied by a cluster. At the final stage of adsorption, HO molecules are believed to form H-bonded bridges between the hexameric water/cation clusters on the basal faces, whereas on the edge faces no such effect is believed to occur. The mean molar integral adsorption entropy of water is ∼-7 J/mol K less than the molar entropy of the bulk liquid. The mobility of HO on muscovite is slightly less than in bulk water. Migration of K cations under the influence of adsorbed HO both on the basal and lateral faces of muscovite is reversible.
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Heats of Adsorption ; Isotherm ; Muscovite ; Potassium Ion ; Water Vapor
Published in:	Clays and Clay Minerals, Vol. 54, Núm. 3 (2006) , p. 402-407, ISSN 1552-8367

DOI: 10.1346/CCMN.2006.0540311

6 p, 488.5 KB  UAB restricted access

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