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Crystal morphology of hydrogenated castor oil in the crystallization of oil - in - water emulsions / Dingzheng Yang in Industrial & engineering chemistry research, Vol. 50 N° 20 (Octobre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 20 (Octobre 2011) . - pp. 11585-11593 Titre : Crystal morphology of hydrogenated castor oil in the crystallization of oil - in - water emulsions : part I. effect of temperature Type de document : texte imprimé Auteurs : Dingzheng Yang, Auteur ; Andrew N. Hrymak, Auteur Année de publication : 2011 Article en page(s) : pp. 11585-11593 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Temperature  effect  Emulsion  Crystallization  Crystal  morphology Résumé : Crystallization of hydrogenated castor oil-in-water emulsions has been studied by polarized light microscopy, scanning electron microscopy, X-ray powder diffraction, and differential scanning calorimetry. Three types of crystal morphologies have been observed: rosettes, fibers, and irregular crystals. The energy barrier to nucleation for fibers is suggested to be higher than that of rosettes. Irregular crystals are thermodynamically less stable and tend to transform into stable polymorphs. Under isothermal crystallization at a temperature of 70 °C, mainly rosettes are observed. With an increase of supercooling, by decreasing the temperature to 55 °C, more fibers form due to a lower energy barrier to nucleation. If the crystallization temperature is set to 45 °C, irregular crystals form first and then transform into rosettes. A nonisothermal crystallization study shows that at a cooling rate of 1 °C/min, more rosettes and fibers are produced compared to a higher cooling rate of 5 °C/min, which produces more irregular crystals. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24612382 [article] Crystal morphology of hydrogenated castor oil in the crystallization of oil - in - water emulsions : part I. effect of temperature [texte imprimé] / Dingzheng Yang, Auteur ; Andrew N. Hrymak, Auteur . - 2011 . - pp. 11585-11593. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 20 (Octobre 2011) . - pp. 11585-11593 Mots-clés : Temperature  effect  Emulsion  Crystallization  Crystal  morphology Résumé : Crystallization of hydrogenated castor oil-in-water emulsions has been studied by polarized light microscopy, scanning electron microscopy, X-ray powder diffraction, and differential scanning calorimetry. Three types of crystal morphologies have been observed: rosettes, fibers, and irregular crystals. The energy barrier to nucleation for fibers is suggested to be higher than that of rosettes. Irregular crystals are thermodynamically less stable and tend to transform into stable polymorphs. Under isothermal crystallization at a temperature of 70 °C, mainly rosettes are observed. With an increase of supercooling, by decreasing the temperature to 55 °C, more fibers form due to a lower energy barrier to nucleation. If the crystallization temperature is set to 45 °C, irregular crystals form first and then transform into rosettes. A nonisothermal crystallization study shows that at a cooling rate of 1 °C/min, more rosettes and fibers are produced compared to a higher cooling rate of 5 °C/min, which produces more irregular crystals. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24612382

Crystal morphology of hydrogenated castor oil in the crystallization of oil - in - water emulsions / Dingzheng Yang in Industrial & engineering chemistry research, Vol. 50 N° 20 (Octobre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 20 (Octobre 2011) . - pp. 11594-11600 Titre : Crystal morphology of hydrogenated castor oil in the crystallization of oil - in - water emulsions : part II. effect of shear Type de document : texte imprimé Auteurs : Dingzheng Yang, Auteur ; Andrew N. Hrymak, Auteur ; Musa R. Kamal, Auteur Année de publication : 2011 Article en page(s) : pp. 11594-11600 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Shear  Emulsion  Crystallization  Crystal  morphology Résumé : Crystallization of hydrogenated castor oil-in-water emulsions has been studied by polarized light microscopy under controlled shear. Shear rates from 0 to 100 s-1 have been applied at cooling rates from 1 to 5 °C/min. Emulsions have been redispersed by shear before crystals formed. The higher the shear rate, the smaller the droplet size. Nucleation has been promoted with the increase of shear rate. Morphology analysis indicates that crystals in the form of fibers favor gentle shear, i.e., 1 s-1, but fibers can be broken up with the increase of shear time. Crystals as rosettes tend to become elongated in the flow direction. At lower cooling rate (<2 °C/min), mean crystal size decreases with shear rate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24612383 [article] Crystal morphology of hydrogenated castor oil in the crystallization of oil - in - water emulsions : part II. effect of shear [texte imprimé] / Dingzheng Yang, Auteur ; Andrew N. Hrymak, Auteur ; Musa R. Kamal, Auteur . - 2011 . - pp. 11594-11600. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 20 (Octobre 2011) . - pp. 11594-11600 Mots-clés : Shear  Emulsion  Crystallization  Crystal  morphology Résumé : Crystallization of hydrogenated castor oil-in-water emulsions has been studied by polarized light microscopy under controlled shear. Shear rates from 0 to 100 s-1 have been applied at cooling rates from 1 to 5 °C/min. Emulsions have been redispersed by shear before crystals formed. The higher the shear rate, the smaller the droplet size. Nucleation has been promoted with the increase of shear rate. Morphology analysis indicates that crystals in the form of fibers favor gentle shear, i.e., 1 s-1, but fibers can be broken up with the increase of shear time. Crystals as rosettes tend to become elongated in the flow direction. At lower cooling rate (<2 °C/min), mean crystal size decreases with shear rate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24612383