| Autor: |
Carlos Alberto Ríos Reyes, Craig Williams, Oscar Mauricio Castellanos Alarcón |
| Jazyk: |
angličtina |
| Rok vydání: |
2013 |
| Předmět: |
|
| Zdroj: |
Materials Research, Vol 16, Iss 2, Pp 424-438 (2013) |
| Druh dokumentu: |
article |
| ISSN: |
1516-1439 |
| Popis: |
The synthesis of low-silica zeotypes by hydrothermal transformation of kaolinite-rich clay and the nucleation and growth processes of sodalite and cancrinite in the system Na2O-Al2O3-SiO2-H2O at 100 °C were investigated. The synthesis products were characterized by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), 29Si and 27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR) and thermogravimetric analysis (TGA). Our data show that the sequence of the transformation of phases is: Poorly crystalline aluminosilicate → zeolite LTA → sodalite → sodalite + cancrinite → cancrinite. Synthesized materials appeared stable thermodynamically under the experimental conditions, with zeolite LTA (a metastable phase) occurring as a minor phase, compared with the presence of sodalite and cancrinite. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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