Nanostructured aluminium oxide powders obtained by aspartic acid-nitrate gel-combustion routes
In this work, two new gel-combustion routes for the synthesis of Al2O3 nanopowders with aspartic acid as fuel are presented. The first route is a conventional stoichiometric process, while the second one is a non-stoichiometric, pH-controlled process. These routes were compared with similar synthesi...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2010 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/77473 |
| Acceso en línea: | http://hdl.handle.net/11336/77473 |
| Access Level: | acceso abierto |
| Palabra clave: | Nanostructured Materials Oxide Materials X-Ray Diffraction https://purl.org/becyt/ford/2.10 https://purl.org/becyt/ford/2 |
| Sumario: | In this work, two new gel-combustion routes for the synthesis of Al2O3 nanopowders with aspartic acid as fuel are presented. The first route is a conventional stoichiometric process, while the second one is a non-stoichiometric, pH-controlled process. These routes were compared with similar synthesis procedures using glycine as fuel, which are well-known in the literature. The samples were calcined in air at different temperatures, in a range of 600-1200 °C. They were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and BET specific surface area. Different phases were obtained depending on the calcination temperature: amorphous, γ (metastable) or α (stable). The amorphous-to-γ transition was found for calcination temperatures in the range of 700-900 °C, while the γ-to-α one was observed for calcination temperatures of 1100-1200 °C. The retention of the metastable γ phase is probably due to a crystallite size effect. It transforms to the α phase after the crystallite size increases over a critical size during the calcination process at 1200 °C. The highest BET specific surface areas were obtained for both nitrate-aspartic acid routes proposed in this work, reaching values of about 50 m2/g. © 2009 Elsevier B.V. All rights reserved. |
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