Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Smectite in bentonite: Near infrared systematics and estimation of layer charge
Δημιουργός/Συγγραφέας:	Tsiantos C. [EL] Γκιώνης, Βασίλης[EN] Gionis, Vassilis [EL] Χρυσικός, Γεώργιος Δ.[EN] Chryssikos, Georgios D.
Επιμελητής έκδοσης:	Bergaya F. López Galindo A.
Εκδότης:	Elsevier Ltd
Ημερομηνία:	2018
Γλώσσα:	Αγγλικά
ISSN:	0169-1317
DOI:	10.1016/j.clay.2018.01.022
Περίληψη:	The facile and accurate measurement of the layer charge of dioctahedral smectite has been demonstrated recently by means of the O-D method, an infrared-based technique capable of recording the exact position of a dangling O-D (O–H) bond stretch of interlayer water. The present work attempts to transfer this know-how to the near-infrared (NIR) spectra of natural bentonites in anticipation of even higher throughput capabilities. For this reason, the NIR systematics of ~ 70 bentonites in both natural and Na-exchanged form have been analyzed against the mid-infrared-derived layer charges of the same samples. The as determined layer charges were not biased by the nature of the interlayer cations (Ca2 +, Mg2 +, Na+). A linear correlation between the (ν + δ) combination modes of H2O and Al2OH at ~ 5250 and 4525 cm− 1, respectively, was established, confirmed on a broader collection of bentonite samples, and discussed in terms of interlayer and layer chemistry. The (ν + δ) H2O wavenumber was found to correlate linearly with layer charge, but the slope was dependent on interlayer cation due to the cation-dependence of the bending δ Η2Ο fundamental mode. Additionally, PLS chemometric modeling of the NIR spectra was employed successfully to provide layer charge predictive algorithms, desensitized from the effect of interlayer cation (Ca2 +, Mg2 +, Na+).
Τίτλος πηγής δημοσίευσης:	Applied Clay Science
Τόμος/Κεφάλαιο:	160
Σελίδες:	81-87
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry [EL] Φασματοσκοπία[EN] Spectroscopy
Λέξεις-Κλειδιά:	Bentonite Dioctahedral smectite Layer-charge NIR spectroscopy PLS chemometrics
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© 2018 Elsevier B.V.
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο