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Effect of mixing and other operating parameters in sol-gel processes / Daniele L. Marchisio in Industrial & engineering chemistry research, Vol. 47 N°19 (Octobre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°19 (Octobre 2008) . - p. 7202–7210 Titre : Effect of mixing and other operating parameters in sol-gel processes Type de document : texte imprimé Auteurs : Daniele L. Marchisio, Auteur ; Federica Omegna, Auteur ; Antonello A. Barresi, Auteur Année de publication : 2008 Article en page(s) : p. 7202–7210 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Sol-gel  process  Titanium  dioxide  synthesis  Thermal  treatments Résumé : In this work the effect of mixing on a sol−gel process is quantitatively investigated. Titanium dioxide synthesis from titanium tetra-isopropoxide is used as a test reaction. Solutions of titanium alkoxide in isopropyl alcohol and water in isopropyl alcohol are mixed in a special mixing device (i.e., vortex reactor) at different mixing rates, and the effect of mixing is quantified and compared with the effect of the other relevant operating parameters, namely the water to alkoxide, acid to alkoxide ratios, and alkoxide initial concentration. Dynamic light scattering, specific surface area measurement through nitrogen adsorption, X-ray diffraction, and field emission scanning electron microscopy are employed to determine particle size distribution, morphology, and crystallite size of the different particulate products (i.e., sols, gels, powders) obtained before and after thermal treatments under different synthesis conditions. A factorial design is used to plan the experimental campaign and results show that the role of mixing cannot be neglected. Moreover results show that mixing can be actively used to control the final product characteristics and must be taken into account when a process is transferred from the laboratory to the industrial scale. Eventually a scale-up criterion based on our previous work will be discussed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800217b [article] Effect of mixing and other operating parameters in sol-gel processes [texte imprimé] / Daniele L. Marchisio, Auteur ; Federica Omegna, Auteur ; Antonello A. Barresi, Auteur . - 2008 . - p. 7202–7210. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°19 (Octobre 2008) . - p. 7202–7210 Mots-clés : Sol-gel  process  Titanium  dioxide  synthesis  Thermal  treatments Résumé : In this work the effect of mixing on a sol−gel process is quantitatively investigated. Titanium dioxide synthesis from titanium tetra-isopropoxide is used as a test reaction. Solutions of titanium alkoxide in isopropyl alcohol and water in isopropyl alcohol are mixed in a special mixing device (i.e., vortex reactor) at different mixing rates, and the effect of mixing is quantified and compared with the effect of the other relevant operating parameters, namely the water to alkoxide, acid to alkoxide ratios, and alkoxide initial concentration. Dynamic light scattering, specific surface area measurement through nitrogen adsorption, X-ray diffraction, and field emission scanning electron microscopy are employed to determine particle size distribution, morphology, and crystallite size of the different particulate products (i.e., sols, gels, powders) obtained before and after thermal treatments under different synthesis conditions. A factorial design is used to plan the experimental campaign and results show that the role of mixing cannot be neglected. Moreover results show that mixing can be actively used to control the final product characteristics and must be taken into account when a process is transferred from the laboratory to the industrial scale. Eventually a scale-up criterion based on our previous work will be discussed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800217b