Comparative study of the textural and structural properties of the aerogel and xerogel sulphated zirconia
Autor: | Abdelhamid Ghorbel, M. K. Younes, Imène Mejri |
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Rok vydání: | 2006 |
Předmět: |
Materials science
Mineralogy Aerogel General Chemistry Condensed Matter Physics Electronic Optical and Magnetic Materials Amorphous solid law.invention Biomaterials Tetragonal crystal system Chemical engineering law Phase (matter) Materials Chemistry Ceramics and Composites Cubic zirconia Atomic ratio Calcination Monoclinic crystal system |
Zdroj: | Journal of Sol-Gel Science and Technology. 40:3-8 |
ISSN: | 1573-4846 0928-0707 |
Popis: | Aerogel and xerogel sulphated zirconia with defined atomic ratio S/Zr = 0.5 and molar hydrolysis ratio h = nH2O/nZrO2 = 3 show different textural and structural properties after calcination at high temperatures. The aerogel obtained just after solvent evacuation develops only the tetragonal phase, whereas the xerogel dried in an oven is amorphous. Heating to a temperature above 833 K, leads to transition of the tetragonal phase to the monoclinic one for the two solids, due to sulphur loss but the tetragonal phase remains stable for the aerogel . Raman, Infrared and XPS spectroscopies show that the loss of the sulphur at high temperatures seems to be easier for the xerogel than for the aerogel. |
Databáze: | OpenAIRE |
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