Documents disponibles écrits par cet auteur

Emulsion stability in the presence of nonionic surfactant micelles / Youngsun Kong in Industrial & engineering chemistry research, Vol. 49 N° 11 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5299–5303 Titre : Emulsion stability in the presence of nonionic surfactant micelles : role of micellar ordering and ostwald ripening Type de document : texte imprimé Auteurs : Youngsun Kong, Auteur ; Alex Nikolov, Auteur ; Darsh Wasan, Auteur Année de publication : 2010 Article en page(s) : pp. 5299–5303 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Emulsion  Micellar  Ordering Résumé : The phenomenon of surfactant micelle ordering (i.e., stratification) in emulsion films was investigated using the reflected-light microinterferometric technique. In thinning films formed from a nonionic micellar solution of ethoxylated alcohol (1 wt %), it was found that the small droplets (i.e., less than 5 µm) are separated by thick (>0.1 µm) stable films containing surfactant micelles in multilayers that prevent droplet flocculation and coalescence. The Ostwald ripening process governs emulsion stability over a long-term. The direct microscopic observations of the evolution of the drop size distribution over time of hexadecane drops (25 vol %) dispersed in an aqueous micellar solution (≈ 120 times critical micellar concentration) was compared with that calculated from the Ostwald ripening model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901825c [article] Emulsion stability in the presence of nonionic surfactant micelles : role of micellar ordering and ostwald ripening [texte imprimé] / Youngsun Kong, Auteur ; Alex Nikolov, Auteur ; Darsh Wasan, Auteur . - 2010 . - pp. 5299–5303. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5299–5303 Mots-clés : Emulsion  Micellar  Ordering Résumé : The phenomenon of surfactant micelle ordering (i.e., stratification) in emulsion films was investigated using the reflected-light microinterferometric technique. In thinning films formed from a nonionic micellar solution of ethoxylated alcohol (1 wt %), it was found that the small droplets (i.e., less than 5 µm) are separated by thick (>0.1 µm) stable films containing surfactant micelles in multilayers that prevent droplet flocculation and coalescence. The Ostwald ripening process governs emulsion stability over a long-term. The direct microscopic observations of the evolution of the drop size distribution over time of hexadecane drops (25 vol %) dispersed in an aqueous micellar solution (≈ 120 times critical micellar concentration) was compared with that calculated from the Ostwald ripening model. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901825c

Emulsion texture and stability / Youngsun Kong in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9108–9114 Titre : Emulsion texture and stability : role of surfactant micellar interactions in the presence of proteins Type de document : texte imprimé Auteurs : Youngsun Kong, Auteur ; Alex Nikolov, Auteur ; Darsh Wasan, Auteur Année de publication : 2009 Article en page(s) : p. 9108–9114 Note générale : Chemistry engineering Langues : Anglais (eng) Mots-clés : Texture  and  Stability  Role  of  Surfactant  Micellar  Presence  of  Proteins Résumé : This article presents the results of our recent research on the texture and stability of oil-in-water emulsions containing sucrose ester and proteins. We used both the direct microscopic imaging and nondestructive back-light scattering (Kossel diffraction) techniques to evaluate the emulsion texture and the energy barrier between droplets for two different emulsifier compositions with and without the proteins present. The microinterferometric method employing our capillary force balance was used to study the stability of the confined thin film (containing surfactant micelles and proteins) between two droplets. In addition to the film stability, we also measured the second virial coefficient of the micellar solutions with and without protein and assessed the intermicellar interaction and related it to the stabilities of the emulsions prepared using two different emulsifier compositions. The effect of protein on the oil-in-water emulsion stability was also assessed and was found to lead to the depletion attraction between droplets, resulting in a less stable emulsion. The results offer new insight into the understanding of how the micellar interactions in the presence of proteins affect emulsion texture and stability. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001815 [article] Emulsion texture and stability : role of surfactant micellar interactions in the presence of proteins [texte imprimé] / Youngsun Kong, Auteur ; Alex Nikolov, Auteur ; Darsh Wasan, Auteur . - 2009 . - p. 9108–9114. Chemistry engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 9108–9114 Mots-clés : Texture  and  Stability  Role  of  Surfactant  Micellar  Presence  of  Proteins Résumé : This article presents the results of our recent research on the texture and stability of oil-in-water emulsions containing sucrose ester and proteins. We used both the direct microscopic imaging and nondestructive back-light scattering (Kossel diffraction) techniques to evaluate the emulsion texture and the energy barrier between droplets for two different emulsifier compositions with and without the proteins present. The microinterferometric method employing our capillary force balance was used to study the stability of the confined thin film (containing surfactant micelles and proteins) between two droplets. In addition to the film stability, we also measured the second virial coefficient of the micellar solutions with and without protein and assessed the intermicellar interaction and related it to the stabilities of the emulsions prepared using two different emulsifier compositions. The effect of protein on the oil-in-water emulsion stability was also assessed and was found to lead to the depletion attraction between droplets, resulting in a less stable emulsion. The results offer new insight into the understanding of how the micellar interactions in the presence of proteins affect emulsion texture and stability. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8001815