Ιδρυματικό Αποθετήριο
Πολυτεχνείο Κρήτης
Πολυτεχνείο Κρήτης
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| URI | http://purl.tuc.gr/dl/dias/5E2C5A62-88B8-4046-AB03-269B333C6C7D | - |
| Αναγνωριστικό | https://doi.org/10.1127/0935-1221/2008/0020-1802 | - |
| Γλώσσα | en | - |
| Μέγεθος | 18 pages | en |
| Τίτλος | Ion exchange equilibrium and structural changes in clinoptilolite irradiated with β- and γ-radiation. Part II: Divalent cations | en |
| Δημιουργός | Daniel Moraetis | en |
| Δημιουργός | Christidis Georgios | en |
| Δημιουργός | Χρηστιδης Γεωργιος | el |
| Δημιουργός | Vasilios Perdikatsis | en |
| Εκδότης | E Schweizerbart Science Publishers | en |
| Περίληψη | Thermodynamic calculations of ion exchange for divalent cations were made for clinoptilolite in natural state and after irradiation with three different doses of β-radiation (1012, 1015 and 3 × 1016 e/cm2) and γ-radiation (70 Mrad). The samples were equilibrated with binary systems of divalent cations, namely Sr2+ ↔ 2Na+, Ca2+ ↔ 2Na+ and Mg2+ ↔ 2Na+ at 25 ◦C and total solution normality of 0.025 N. The selectivity order Sr2+ > Ca2+ > Mg2+ was observed in non-irradiated clinoptilolite. After irradiation with γ-radiation the affinity of clinoptilolite for Sr2+ increased and that for Mg2+ decreased, whereas the affinity for Ca2+ remained unchanged. Irradiation with β-radiation influences selectivity order and clinoptilolite affinity decreases for Sr2+, whereas it increases for Ca2+. For the sample irradiated with maximum dose of β-radiation the selectivity was almost identical for Ca2+ and Sr2+. The crystallographic parameters and exchangeable cation site coordinates were refined for all samples with the Rietveld method. The structure refinement of Sr2+-saturated samples yielded changes both in exchangeable sites and site occupancy in channels A and B after irradiation with β-and γ-radiation. The cation sites Sr1 and Sr3 exhibit major changes both in site coordinates and site occupancy after irradiation with β-radiation. In addition, irradiation with γ-radiation yielded major changes in Sr1 occupancy, whereas coordinates changed only slightly. These structural modifications control the observed changes in thermodynamic parameters after irradiation. | en |
| Τύπος | Peer-Reviewed Journal Publication | en |
| Τύπος | Δημοσίευση σε Περιοδικό με Κριτές | el |
| Άδεια Χρήσης | http://creativecommons.org/licenses/by/4.0/ | en |
| Ημερομηνία | 2015-10-01 | - |
| Ημερομηνία Δημοσίευσης | 2008 | - |
| Βιβλιογραφική Αναφορά | D. Moraetis,G.E. Christidis , V.Perdikatsis , "Ion exchange equilibrium and structural changes in clinoptilolite irradiated with β- and γ-radiation. Part II: Divalent cations ",Eur. J. Mineral ,vol.20, no.4.,pp.603-620 ,2008. doi :10.1127/0935-1221/2008/0020-1802 | en |
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