Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Measuring the layer charge of dioctahedral smectite by O-D vibrational spectroscopy
Δημιουργός/Συγγραφέας:	Kuligiewicz A. Derkowski A. Emmerich K. Christidis G.E. Tsiantos C. [EL] Γκιώνης, Βασίλης[EN] Gionis, Vassilis [EL] Χρυσικός, Γεώργιος Δ.[EN] Chryssikos, Georgios D.
Εκδότης:	Clay Minerals Society
Ημερομηνία:	2015
Γλώσσα:	Αγγλικά
ISSN:	0009-8604
DOI:	10.1346/CCMN.2015.0630603
Περίληψη:	Layer charge (LC) is a fundamental property of smectite but its measurement remains challenging and tedious to apply on a high-throughput basis. The present study demonstrates that the position of a sharp, high-energy O-D stretching band of adsorbed D2O (nO-D, at ~2686_2700 cm_1), determined by infrared spectroscopy, correlates with LC and provides a simple method for its measurement. Twenty nine natural dioctahedral smectites and 14 reduced-charge montmorillonites with LC determined previously by different methodologies were saturated with D2O and examined by attenuated total reflectance infrared spectroscopy (ATR-IR). The samples included smectites in Mg, Ca, Na, Li, K, and Cs forms and covered the full range of the smectite LC (0.2 to 0.6 e per formula unit). Statistically significant correlations were found between nO-D and LC values determined with each of the two main methods of LC determination: the structural formula method (R2 = 0.96, s = 0.02, ~0.2 < LC < 0.6) and the alkylammonium method (R2 = 0.92, s = 0.01, 0.27 < LC < 0.37). These correlations were based on Li- and Na-saturated smectites, respectively, but other cationic forms can be employed provided that the exchangeable cations are of sufficiently high hydration enthalpy (e.g. Mg2+ or Ca2+, but not K+ or Cs+). The new method is fast, low-cost, implemented easily in laboratories equipped with ATR-FTIR, and applicable to samples as small as ~5 mg.
Τίτλος πηγής δημοσίευσης:	Clays and Clay Minerals
Τόμος/Κεφάλαιο:	63
Τεύχος:	6
Σελίδες:	443-456
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry [EL] Φασματοσκοπία[EN] Spectroscopy
Λέξεις-Κλειδιά:	ATR D2O Infrared spectroscopy Layer charge Smectite
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© 2015, Clays and Clay Minerals. All rights reserved.
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο