Documents disponibles écrits par cet auteur

Analysis of the princen and kiss equation to model the storage modulus of highly concentrated emulsions / Emilio Paruta-Tuarez in Industrial & engineering chemistry research, Vol. 50 N° 17 (Septembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 10359-10365 Titre : Analysis of the princen and kiss equation to model the storage modulus of highly concentrated emulsions Type de document : texte imprimé Auteurs : Emilio Paruta-Tuarez, Auteur ; Philippe Marchal, Auteur ; Veronique Sadtler, Auteur Année de publication : 2011 Article en page(s) : pp. 10359-10365 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Emulsion  Storage  Modeling Résumé : The universality of the model proposed by Princen and Kiss is analyzed in the case of highly concentrated water-in-oil emulsions containing dispersed-phase volume fractions (φ) ranging from 0.89 to 0.97. Although Princen and Kiss equation has been rigorously established for a two-dimensional system and involves no adjustable parameter, the model for a tridimensional system, which is an extrapolation of the 2D model, requires the introduction of a phenomenological linear function E(φ) to account for experimental deviations. As mentioned by Princen and Kiss themselves, there is no satisfactory theoretical derivation of E(φ). Indeed, in this paper we point out that the linear dependence in φ of E(φ) is a consequence of the particular set of experimental data exploited by Princen and Kiss. Another choice of experimental data could have led to propose other mathematical functions since at very high volume fraction, some experimental data found in the literature show a more rapid increase of the storage modulus G′ with φ than predicted by Princen and Kiss equation, which tends to underestimate the values of G′. Finally, for the studied highly concentrated emulsions, the dispersed-phase volume fraction dependence of storage modulus is discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483682 [article] Analysis of the princen and kiss equation to model the storage modulus of highly concentrated emulsions [texte imprimé] / Emilio Paruta-Tuarez, Auteur ; Philippe Marchal, Auteur ; Veronique Sadtler, Auteur . - 2011 . - pp. 10359-10365. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 10359-10365 Mots-clés : Emulsion  Storage  Modeling Résumé : The universality of the model proposed by Princen and Kiss is analyzed in the case of highly concentrated water-in-oil emulsions containing dispersed-phase volume fractions (φ) ranging from 0.89 to 0.97. Although Princen and Kiss equation has been rigorously established for a two-dimensional system and involves no adjustable parameter, the model for a tridimensional system, which is an extrapolation of the 2D model, requires the introduction of a phenomenological linear function E(φ) to account for experimental deviations. As mentioned by Princen and Kiss themselves, there is no satisfactory theoretical derivation of E(φ). Indeed, in this paper we point out that the linear dependence in φ of E(φ) is a consequence of the particular set of experimental data exploited by Princen and Kiss. Another choice of experimental data could have led to propose other mathematical functions since at very high volume fraction, some experimental data found in the literature show a more rapid increase of the storage modulus G′ with φ than predicted by Princen and Kiss equation, which tends to underestimate the values of G′. Finally, for the studied highly concentrated emulsions, the dispersed-phase volume fraction dependence of storage modulus is discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483682

Emulsion catastrophic inversion from abnormal to normal morphology. 8. Effect of formulation on the inversion produced by continuous stirring / Marianna Rondón-González in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 2913–2919 Titre : Emulsion catastrophic inversion from abnormal to normal morphology. 8. Effect of formulation on the inversion produced by continuous stirring Type de document : texte imprimé Auteurs : Marianna Rondón-González, Auteur ; Luis F. Madariaga, Auteur ; Veronique Sadtler, Auteur Année de publication : 2009 Article en page(s) : pp. 2913–2919 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Water-oil-surfactant  system  Hydrophilic-lipophilic  difference  Continuous  stirring Résumé : This paper deals with the influence of the global formulation of a water−oil−surfactant system, expressed by the hydrophilic−lipophilic difference (HLD), on the emulsion inversion produced just by the continuous stirring of an abnormal system, without any internal phase addition or any composition change. Evidence confirms that, under stirring, a w/O/W multiple emulsion is formed by the continuous inclusion of the external water phase inside the dispersed drops, which results in an increase of the effective dispersed phase volume until a critical value at which the inversion is triggered. Results suggest that the stability of the most internal emulsion determines the kinetics of inclusion and the stirring time required to induce inversion. However, it is the stability of both internal (w/O) and external (O/W) emulsions which determines the dispersed phase fraction at which the inversion is triggered. When different water fractions are used, the change of the critical dispersed phase fraction reveals that this process is affected by the partitioning of the surfactant mixture species between phases and results confirm that the critical dispersed phase fraction is a property related to the interfacial formulation of the system. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801225h [article] Emulsion catastrophic inversion from abnormal to normal morphology. 8. Effect of formulation on the inversion produced by continuous stirring [texte imprimé] / Marianna Rondón-González, Auteur ; Luis F. Madariaga, Auteur ; Veronique Sadtler, Auteur . - 2009 . - pp. 2913–2919. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 2913–2919 Mots-clés : Water-oil-surfactant  system  Hydrophilic-lipophilic  difference  Continuous  stirring Résumé : This paper deals with the influence of the global formulation of a water−oil−surfactant system, expressed by the hydrophilic−lipophilic difference (HLD), on the emulsion inversion produced just by the continuous stirring of an abnormal system, without any internal phase addition or any composition change. Evidence confirms that, under stirring, a w/O/W multiple emulsion is formed by the continuous inclusion of the external water phase inside the dispersed drops, which results in an increase of the effective dispersed phase volume until a critical value at which the inversion is triggered. Results suggest that the stability of the most internal emulsion determines the kinetics of inclusion and the stirring time required to induce inversion. However, it is the stability of both internal (w/O) and external (O/W) emulsions which determines the dispersed phase fraction at which the inversion is triggered. When different water fractions are used, the change of the critical dispersed phase fraction reveals that this process is affected by the partitioning of the surfactant mixture species between phases and results confirm that the critical dispersed phase fraction is a property related to the interfacial formulation of the system. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801225h

Heteroflocculation of a cationic oil - in - water emulsion resulting from fontainebleau’s sandstone powder addition as a model for asphalt emulsion breakup / Ronald A. Mercado in Industrial & engineering chemistry research, Vol. 51 N° 36 (Septembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11688-11694 Titre : Heteroflocculation of a cationic oil - in - water emulsion resulting from fontainebleau’s sandstone powder addition as a model for asphalt emulsion breakup Type de document : texte imprimé Auteurs : Ronald A. Mercado, Auteur ; Veronique Sadtler, Auteur ; Philippe Marchal, Auteur Année de publication : 2012 Article en page(s) : pp. 11688-11694 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Modeling  Powder  Emulsion Résumé : The use of asphalt emulsions for road fabrication is rapidly gaining in importance mainly due to energy savings, less environmental impact, and better properties of the final product. However, the formulation of these emulsions still requires a better understanding, particularly concerning their breaking phenomena. When a cationic model emulsion is contacted with a solid having a negative-charged surface, physicochemical driving forces result in the emulsion destabilization. As a consequence, a viscosity reduction of the remaining emulsion is observed, as well as the emulsion breakup through a heteroflocculation mechanism provided the solid surface is large enough. Emulsion systems at equilibrium, containing cetylpyridinium chloride (CPC), paraffin oil, and Fontainebleau's sandstone powder and having different droplet sizes, are studied. The results show that the dispersed oil fraction decreases after each addition of sandstone aliquots, and this depends on the concentration of CPC in the continuous phase of the emulsion. As the droplet size and distribution remain constant during the process, it is assumed that the emulsion heteroflocculation is the result of direct oil droplets adhesion on the sand surface, followed by their coalescence around the sand particles. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26350336 [article] Heteroflocculation of a cationic oil - in - water emulsion resulting from fontainebleau’s sandstone powder addition as a model for asphalt emulsion breakup [texte imprimé] / Ronald A. Mercado, Auteur ; Veronique Sadtler, Auteur ; Philippe Marchal, Auteur . - 2012 . - pp. 11688-11694. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11688-11694 Mots-clés : Modeling  Powder  Emulsion Résumé : The use of asphalt emulsions for road fabrication is rapidly gaining in importance mainly due to energy savings, less environmental impact, and better properties of the final product. However, the formulation of these emulsions still requires a better understanding, particularly concerning their breaking phenomena. When a cationic model emulsion is contacted with a solid having a negative-charged surface, physicochemical driving forces result in the emulsion destabilization. As a consequence, a viscosity reduction of the remaining emulsion is observed, as well as the emulsion breakup through a heteroflocculation mechanism provided the solid surface is large enough. Emulsion systems at equilibrium, containing cetylpyridinium chloride (CPC), paraffin oil, and Fontainebleau's sandstone powder and having different droplet sizes, are studied. The results show that the dispersed oil fraction decreases after each addition of sandstone aliquots, and this depends on the concentration of CPC in the continuous phase of the emulsion. As the droplet size and distribution remain constant during the process, it is assumed that the emulsion heteroflocculation is the result of direct oil droplets adhesion on the sand surface, followed by their coalescence around the sand particles. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26350336

Influence of semibatch emulsification process conditions on the physical characteristics of highly concentrated water - in - oil emulsions / Oscar A. Alvarez in Industrial & engineering chemistry research, Vol. 49 N° 13 (Juillet 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 13 (Juillet 2010) . - pp. 6042–6046 Titre : Influence of semibatch emulsification process conditions on the physical characteristics of highly concentrated water - in - oil emulsions Type de document : texte imprimé Auteurs : Oscar A. Alvarez, Auteur ; Lionel Choplin, Auteur ; Veronique Sadtler, Auteur Année de publication : 2010 Article en page(s) : pp. 6042–6046 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oil  Emulsions Résumé : We studied the energy consumption per unit volume during preparation of highly concentrated water-in-oil emulsions in a two-step semibatch process. In particular, we studied the effect of two process variables, the water addition flow rate (Qw) and the agitation speed (N). The oil used for emulsion preparation was n-dodecane, the surfactant was sorbitan monooleate (Span 80) and deionized water was used for the dispersed phase. The results obtained showed that two steps were required to get complete incorporation of the dispersed phase and a homogeneous and stable gel-emulsion. With the help of independent physical characteristics measurement performed at the end of the preparation process, we established two functional relationships, relating storage modulus (G′) with energy consumption (Ev), (G′ Ev0.6), and average liquid cell size (Rm) of the dispersed phase with energy consumption (Ev), (Rm EV−0.3). A structural scaling law can be deduced that relates the elastic modulus to the reciprocal of the square of the average liquid’s cell size of the gel-emulsion, corroborated by independent measurements and predicted by recent published models. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020073 [article] Influence of semibatch emulsification process conditions on the physical characteristics of highly concentrated water - in - oil emulsions [texte imprimé] / Oscar A. Alvarez, Auteur ; Lionel Choplin, Auteur ; Veronique Sadtler, Auteur . - 2010 . - pp. 6042–6046. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 13 (Juillet 2010) . - pp. 6042–6046 Mots-clés : Oil  Emulsions Résumé : We studied the energy consumption per unit volume during preparation of highly concentrated water-in-oil emulsions in a two-step semibatch process. In particular, we studied the effect of two process variables, the water addition flow rate (Qw) and the agitation speed (N). The oil used for emulsion preparation was n-dodecane, the surfactant was sorbitan monooleate (Span 80) and deionized water was used for the dispersed phase. The results obtained showed that two steps were required to get complete incorporation of the dispersed phase and a homogeneous and stable gel-emulsion. With the help of independent physical characteristics measurement performed at the end of the preparation process, we established two functional relationships, relating storage modulus (G′) with energy consumption (Ev), (G′ Ev0.6), and average liquid cell size (Rm) of the dispersed phase with energy consumption (Ev), (Rm EV−0.3). A structural scaling law can be deduced that relates the elastic modulus to the reciprocal of the square of the average liquid’s cell size of the gel-emulsion, corroborated by independent measurements and predicted by recent published models. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020073

Viscous oil emulsification by catastrophic phase inversion / Johanna Galindo-Alvarez in Industrial & engineering chemistry research, Vol. 50 N° 9 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5575-5583 Titre : Viscous oil emulsification by catastrophic phase inversion : influence of oil viscosity and process conditions Type de document : texte imprimé Auteurs : Johanna Galindo-Alvarez, Auteur ; Veronique Sadtler, Auteur ; Lionel Choplin, Auteur Année de publication : 2011 Article en page(s) : pp. 5575-5583 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Viscosity  Phase  reversal  Emulsification Résumé : This study deals with the description of the influence of oil viscosity and process conditions on catastrophic phase inversion, through the analysis of the effects of formulation and process variables on the dispersed phase fraction at which the inversion is triggered. The in situ simultaneous follow-up of viscosity and conductivity measurements allowed, from a process point of view, to emphasize the effect of the aqueous phase addition rate on the catastrophic phase inversion point (PIP) and multiple w/ O/W emulsion formation. Thus if the aqueous phase is added by very small fractions, formulation dominates and the inversion phenomenon can be accelerated, as a consequence of multiple emulsion formation, that greatly increases the volume of effective dispersed phase. An increase in oil viscosity greatly increased the tendency of the oily phase to become the dispersed phase and promoted the formation of highly concentrated emulsions (about 80 to 95% in volume) after inversion. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128680 [article] Viscous oil emulsification by catastrophic phase inversion : influence of oil viscosity and process conditions [texte imprimé] / Johanna Galindo-Alvarez, Auteur ; Veronique Sadtler, Auteur ; Lionel Choplin, Auteur . - 2011 . - pp. 5575-5583. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 9 (Mai 2011) . - pp. 5575-5583 Mots-clés : Viscosity  Phase  reversal  Emulsification Résumé : This study deals with the description of the influence of oil viscosity and process conditions on catastrophic phase inversion, through the analysis of the effects of formulation and process variables on the dispersed phase fraction at which the inversion is triggered. The in situ simultaneous follow-up of viscosity and conductivity measurements allowed, from a process point of view, to emphasize the effect of the aqueous phase addition rate on the catastrophic phase inversion point (PIP) and multiple w/ O/W emulsion formation. Thus if the aqueous phase is added by very small fractions, formulation dominates and the inversion phenomenon can be accelerated, as a consequence of multiple emulsion formation, that greatly increases the volume of effective dispersed phase. An increase in oil viscosity greatly increased the tendency of the oily phase to become the dispersed phase and promoted the formation of highly concentrated emulsions (about 80 to 95% in volume) after inversion. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24128680