ISSN:
1573-9171
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Conclusions 1. Partial ionic exchange has been used to prepare a NaMgA zeolite free of delocalized Na+ cations. DTA, TG, and x-ray data have been combined with the ion-exchange isotherm to obtain information concerning the limiting adsorptional volume of the zeolite with respect to H2O, details of the zeolite structure, the presence of contaminating MgO and carbonates, and residual delocalized Na+ cations. Ion exchange leads to stress redistribution in the eight-membered and six-membered oxygen windows, with a 7–10% increase in the limiting adsorption volume. 2. Analysis of the data on the differential heat of adsorption indicates that the propane molecules preferentially localized at the eight-membered oxygen windows where they weakly interact, one with the other, to form loose chain-like structures. 3. Values of the limiting adsorption obtained from the differential heats of adsorption and the isothermal equation of the theory of exchange micropore filling indicate that filling proceeds to the extent of three propane molecules per large NaMgA zeolite cavity, with one propane molecule per eight-membered oxygen window.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00921697
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