Abstract
The aim of this work is to study the addition of oligosaccharides and glycolipids in lamellar phases of the cationic surfactant DDAB (di-dodecyl-dimethyl-ammonium bromide). Two steps have been followed: the determination of phases prisms and the thermodynamic interpretation in terms of molecular interactions. In order to characterize these systems, two new experimental small angle scattering methods have been perfected: 1) a neutron scattering contrast variation method which allows to study the adsorption of aqueous solution in bilayers and 2) a capillary concentration gradient method to establish directly and quantitatively the phases diagrams of ternary systems by X rays scattering. It has been pointed out that the oligosaccharides induce a depletion attractive force on the lamellar-lamellar equilibrium of the DDAB when they are excluded of the most concentrated phase. For the two studied glycolipids: 2-O lauroyl-saccharose and N-lauroyl N-nonyl lactitol, the ternary phase diagrams water-DDAB-glycolipid have been established in terms of temperature. Critical points at ambient temperature have been given. The osmotic pressure in concentrated lamellar phases has been measured. It has been shown that glycolipids increase the hydration repulsion at short distance and that the electrostatic repulsion is outstanding and unchanged at high distance if there is at less 1
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Citation Formats
Ricoul, Florence.
Oligosaccharides and glycolipids addition in charged lamellar phases; Addition d'oligosaccharides et de glycolipides dans des phases lamellaires chargees.
France: N. p.,
1997.
Web.
Ricoul, Florence.
Oligosaccharides and glycolipids addition in charged lamellar phases; Addition d'oligosaccharides et de glycolipides dans des phases lamellaires chargees.
France.
Ricoul, Florence.
1997.
"Oligosaccharides and glycolipids addition in charged lamellar phases; Addition d'oligosaccharides et de glycolipides dans des phases lamellaires chargees."
France.
@misc{etde_302188,
title = {Oligosaccharides and glycolipids addition in charged lamellar phases; Addition d'oligosaccharides et de glycolipides dans des phases lamellaires chargees}
author = {Ricoul, Florence}
abstractNote = {The aim of this work is to study the addition of oligosaccharides and glycolipids in lamellar phases of the cationic surfactant DDAB (di-dodecyl-dimethyl-ammonium bromide). Two steps have been followed: the determination of phases prisms and the thermodynamic interpretation in terms of molecular interactions. In order to characterize these systems, two new experimental small angle scattering methods have been perfected: 1) a neutron scattering contrast variation method which allows to study the adsorption of aqueous solution in bilayers and 2) a capillary concentration gradient method to establish directly and quantitatively the phases diagrams of ternary systems by X rays scattering. It has been pointed out that the oligosaccharides induce a depletion attractive force on the lamellar-lamellar equilibrium of the DDAB when they are excluded of the most concentrated phase. For the two studied glycolipids: 2-O lauroyl-saccharose and N-lauroyl N-nonyl lactitol, the ternary phase diagrams water-DDAB-glycolipid have been established in terms of temperature. Critical points at ambient temperature have been given. The osmotic pressure in concentrated lamellar phases has been measured. It has been shown that glycolipids increase the hydration repulsion at short distance and that the electrostatic repulsion is outstanding and unchanged at high distance if there is at less 1 mole percent of ionic surfactant. In a dilute solution, glycolipids decrease the maximum swelling of lamellar phases, with a competition between the lamellar phase and the micellae dilute phase for water. (O.M.). [French] Le probleme general traite dans ce travail est la caracterisation de l'effet specifique de tetes polaires sucres depassant a la surface d'une bicouche. Nous avons ainsi etudie l'ajout d'oligosaccharides et de glycolipides dans les phases lamellaires du tensioactif cationique DDAB (bromure de didodecyldimethyl ammonium). Deux etapes ont ete suivies : la determination des prismes de phases et l'interpretation thermodynamique en termes rl'interactions moleculaires. Pour caracteriser ces systemes nous avons mis au point deux methodes experimentales originales de diffusion de rayonnements aux petits angles: - une methode par variation de contraste en diffusion de neutrons, qui permet d'etudier l'adsorption de solutes dans des bicouches. - une methode en gradient de concentration en capillaire pour etablir directement et quantitativement les diagrammes de phases de systemes ternaires par diffusion de rayons X. Nous avons observe que les oligosaccharides, c'est-a-dire les tetes polaires sucres libres en solution, induisent sur l'equilibre lamellaire-lamellaire du DDAB une force attractive de depletion lorsqu'ils sont exclus de la phase la plus concentree. Pour les deux glycolipides etudies, 2-0 lauroylsaccharose et N-lauroyl N-nonyl lactitol, nous avons etabli les diagrammes de phases ternaires eau/DDAB/glycolipide en fonction de la temperature. Nous avons mis en evidence des points critiques a temperature ambiante. Nous avons mesure la pression osmotique dans les phases lamellaires concentrees. Nous avons observe que les glycolipides augmentent la repulsion d'hydratation a courte distance, et que la repulsion electrostatique est dominante et inchangee a grande distance tant. qu'il reste au moins 1 % en moles de tensioactif ionique. Enfin, nous avons calcule une energie d'adhesion liee aux tetes polaires carbohydratees pres de 8 fois plus grande que celle du DDAB, a distance egale des parties apolaires. En regime dilue, nous avons observe que les glycolipides diminuent le gonflement maximum des phases lamellaires, avec une competition pour l'eau entre la phase lamellaire et la phase diluee de vesicules ou de micelles suivant le cas. (auteur)}
place = {France}
year = {1997}
month = {Sep}
}
title = {Oligosaccharides and glycolipids addition in charged lamellar phases; Addition d'oligosaccharides et de glycolipides dans des phases lamellaires chargees}
author = {Ricoul, Florence}
abstractNote = {The aim of this work is to study the addition of oligosaccharides and glycolipids in lamellar phases of the cationic surfactant DDAB (di-dodecyl-dimethyl-ammonium bromide). Two steps have been followed: the determination of phases prisms and the thermodynamic interpretation in terms of molecular interactions. In order to characterize these systems, two new experimental small angle scattering methods have been perfected: 1) a neutron scattering contrast variation method which allows to study the adsorption of aqueous solution in bilayers and 2) a capillary concentration gradient method to establish directly and quantitatively the phases diagrams of ternary systems by X rays scattering. It has been pointed out that the oligosaccharides induce a depletion attractive force on the lamellar-lamellar equilibrium of the DDAB when they are excluded of the most concentrated phase. For the two studied glycolipids: 2-O lauroyl-saccharose and N-lauroyl N-nonyl lactitol, the ternary phase diagrams water-DDAB-glycolipid have been established in terms of temperature. Critical points at ambient temperature have been given. The osmotic pressure in concentrated lamellar phases has been measured. It has been shown that glycolipids increase the hydration repulsion at short distance and that the electrostatic repulsion is outstanding and unchanged at high distance if there is at less 1 mole percent of ionic surfactant. In a dilute solution, glycolipids decrease the maximum swelling of lamellar phases, with a competition between the lamellar phase and the micellae dilute phase for water. (O.M.). [French] Le probleme general traite dans ce travail est la caracterisation de l'effet specifique de tetes polaires sucres depassant a la surface d'une bicouche. Nous avons ainsi etudie l'ajout d'oligosaccharides et de glycolipides dans les phases lamellaires du tensioactif cationique DDAB (bromure de didodecyldimethyl ammonium). Deux etapes ont ete suivies : la determination des prismes de phases et l'interpretation thermodynamique en termes rl'interactions moleculaires. Pour caracteriser ces systemes nous avons mis au point deux methodes experimentales originales de diffusion de rayonnements aux petits angles: - une methode par variation de contraste en diffusion de neutrons, qui permet d'etudier l'adsorption de solutes dans des bicouches. - une methode en gradient de concentration en capillaire pour etablir directement et quantitativement les diagrammes de phases de systemes ternaires par diffusion de rayons X. Nous avons observe que les oligosaccharides, c'est-a-dire les tetes polaires sucres libres en solution, induisent sur l'equilibre lamellaire-lamellaire du DDAB une force attractive de depletion lorsqu'ils sont exclus de la phase la plus concentree. Pour les deux glycolipides etudies, 2-0 lauroylsaccharose et N-lauroyl N-nonyl lactitol, nous avons etabli les diagrammes de phases ternaires eau/DDAB/glycolipide en fonction de la temperature. Nous avons mis en evidence des points critiques a temperature ambiante. Nous avons mesure la pression osmotique dans les phases lamellaires concentrees. Nous avons observe que les glycolipides augmentent la repulsion d'hydratation a courte distance, et que la repulsion electrostatique est dominante et inchangee a grande distance tant. qu'il reste au moins 1 % en moles de tensioactif ionique. Enfin, nous avons calcule une energie d'adhesion liee aux tetes polaires carbohydratees pres de 8 fois plus grande que celle du DDAB, a distance egale des parties apolaires. En regime dilue, nous avons observe que les glycolipides diminuent le gonflement maximum des phases lamellaires, avec une competition pour l'eau entre la phase lamellaire et la phase diluee de vesicules ou de micelles suivant le cas. (auteur)}
place = {France}
year = {1997}
month = {Sep}
}