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Crystallization of anatase nanoparticles from amorphous precipitate by a continuous hydrothermal process / Kinga A. Malinger in Chemical engineering journal, Vol. 174 N° 1 (Octobre 2011) 

Public ISBD [article]  in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.445–451 Titre : Crystallization of anatase nanoparticles from amorphous precipitate by a continuous hydrothermal process Type de document : texte imprimé Auteurs : Kinga A. Malinger, Auteur ; Aude Maguer, Auteur ; Alain Thorel, Auteur Année de publication : 2012 Article en page(s) : pp.445–451 Note générale : Génie chimique Langues : Anglais (eng) Mots-clés : Continuous  hydrothermal  crystallization  Anatase  nanoparticles  Fast  synthesis  Continuous  synthes Résumé : Anatase nanoparticles with controlled size in the range 7–13 nm were synthesized by a continuous hydrothermal crystallization of amorphous TiO2 precipitate in a tubular reactor. The amorphous precursor was obtained from a double jet precipitation of TiCl4 with NaOH at pH 3. Hydrothermal crystallization was performed in a tubular reactor. Two main parameters were studied: the mean residence time of the slurry ranged from 10 to 30 min and transformation temperature from 120 to 220 °C. All samples have been characterized by Transmission Electron Microscopy, X-ray diffraction, and specific surface area measurement by N2 adsorption/desorption measurements. Well-crystallized anatase particles were obtained within few minutes at temperatures as low as 120 °C with a low polydispersity. Relationship between particle size and process parameters as temperature and residence time was determined. Due to the very slight variations in particle size vs process parameters, it is necessary to add up several techniques to give a reliable description of the samples as far as average aspect ratio, characteristic size and polydispersity are concerned. We propose to rely on TEM to get the average aspect ratio, then to rely on specific surface area to get the average particle size, and finally to check the consistency of these results with TEM and XRD peaks broadening. This self-consistent approach of particle characterization provides a correct and accurate description of the samples, and helps to optimize process parameters for photocatalytic applications, for instance. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711010230 [article] Crystallization of anatase nanoparticles from amorphous precipitate by a continuous hydrothermal process [texte imprimé] / Kinga A. Malinger, Auteur ; Aude Maguer, Auteur ; Alain Thorel, Auteur . - 2012 . - pp.445–451. Génie chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.445–451 Mots-clés : Continuous  hydrothermal  crystallization  Anatase  nanoparticles  Fast  synthesis  Continuous  synthes Résumé : Anatase nanoparticles with controlled size in the range 7–13 nm were synthesized by a continuous hydrothermal crystallization of amorphous TiO2 precipitate in a tubular reactor. The amorphous precursor was obtained from a double jet precipitation of TiCl4 with NaOH at pH 3. Hydrothermal crystallization was performed in a tubular reactor. Two main parameters were studied: the mean residence time of the slurry ranged from 10 to 30 min and transformation temperature from 120 to 220 °C. All samples have been characterized by Transmission Electron Microscopy, X-ray diffraction, and specific surface area measurement by N2 adsorption/desorption measurements. Well-crystallized anatase particles were obtained within few minutes at temperatures as low as 120 °C with a low polydispersity. Relationship between particle size and process parameters as temperature and residence time was determined. Due to the very slight variations in particle size vs process parameters, it is necessary to add up several techniques to give a reliable description of the samples as far as average aspect ratio, characteristic size and polydispersity are concerned. We propose to rely on TEM to get the average aspect ratio, then to rely on specific surface area to get the average particle size, and finally to check the consistency of these results with TEM and XRD peaks broadening. This self-consistent approach of particle characterization provides a correct and accurate description of the samples, and helps to optimize process parameters for photocatalytic applications, for instance. ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science/article/pii/S1385894711010230