English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/62628
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:


Evolution of phases and Al-Si distribution during Na-4-mica synthesis

AuthorsAlba, María D. ; Castro Arroyo, Miguel Ángel ; Naranjo, Moisés; Orta, M. Mar ; Pavón, Esperanza ; Pazos, M. Carolina
Issue Date2011
PublisherAmerican Chemical Society
CitationJournal of Physical Chemistry C 115: 20084- 20090 (2011)
AbstractNa-4-mica, a highly charged fluorophlogopite, has recently attracted much attention because of its unique combination of high charge (four charges per unit cell) and its swelling and cation-exchange properties. The ability to improve the properties of this mica depends on gaining knowledge about its phase evolution during the calcination process. For the synthesis, the stoichiometric powder mixture (4SiO2/2Al2O3/6MgF 2/8NaCl) was heated to 900 °C for 0-600 h. The obtained solids were characterized by X-ray fluorescence (XRF); X-ray diffraction (XRD); scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) analysis; 29Si, 27Al, and 23Na magic-angle-spinning MAS NMR spectroscopy; and thermogravimetric/differential thermal analysis (TG/DTA). The results showed that the precursors are rapidly (t < 3 h) transformed into sodalite, Al6Na8(SiO4)6Cl 2, and a 2:1 phyllosilicate. For t = 7.5 h, the amount of 2:1 phyllosilicate increased as a result of the decomposition of sodalite, with a progressive incorporation of aluminum in the 2:1 phyllosilicate being observed. For t = 7.5 h, synthesis of Na-4-mica was considered to be complete, as the material remained essentially unaltered for the next 15 h. For t = 30 h, the mica started to decompose, and for very long reaction times (t ≥ 300 h), only forsterite and a carnegierite phase were present. © 2011 American Chemical Society.
Identifiersdoi: 10.1021/jp207408h
issn: 1932-7447
Appears in Collections:(ICMS) Artículos
Files in This Item:
File Description SizeFormat 
accesoRestringido.pdf15,38 kBAdobe PDFThumbnail
Show full item record
Review this work

Related articles:

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.