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Krafft points and Cloud points of polyoxyethylated nonionic surfactants / H. Schott in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 46, N° 1/1009 (01-02/2009)
[article]
Titre : Krafft points and Cloud points of polyoxyethylated nonionic surfactants : part. 3. The effect of hydrotropes and other organic electrolytes Type de document : texte imprimé Auteurs : H. Schott, Auteur Année de publication : 2009 Article en page(s) : p. 39-47 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cations
Electrolytes
Polyéthylène glycol
SurfactantsTags : Polyoxyethylated nonionic surfactants Nonionic Krafft point Effect short organic electrolytes Clouod short-chain of hydrotropes Cloud Kfrafft mixtures cationic Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : The effect of various organic electrolytes on the Krafft point (KP) of two and the cloud point (CP) of three polyoxyethylated nonionic surfactants is described. Additives that lower the KP or raise the CP salt the surfactants in. The short-chain organic electrolytes acetic acid and propionic acid lower the KP of polyoxyl 10 cetyl ether (C16E10) while sodium acetate, propionate and butyrate leave the KP largely unaffected. Sodium acetate and sodium propionate lower the CP of C16E10 substantially. Sodium butyrate raises the CP, presumably by rendering the C16E10 micelles partly ionic via mixed micelle formation. Hydrotropes (sodium benzoate, salicylate and xylene sulfonate, and the nonelectrolyte nicotinamide) lower the KP of polyoxyl 10 stearyl ether (C18E10) substantially at 3.0 m concentrations and raise the CP substantially even at 0.10 m concentrations. The KPs of mixtures of C18E10 (KP = 48°) and hexadecylamine hydrochloride (HDCl, KP = 44°) were measured at a constant total surfactant concentration of 2.0% based on the weight of water. The plot of KP versus the relative weight-percent HDCl is V-shaped with a eutectic minimum of 32° at 33% HDCl. The left branch is entirely linear. It shows how increasing weight-percentages of HDCl lower the KP of C18E10. The right branch is linear up to ca. 80% HDCl but becomes less steep at higher HDCl concentrations. It shows how decreasing weight-percentages of C18E10 raise the KP of HDCl. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3719
in TENSIDE, SURFACTANTS, DETERGENTS > Vol. 46, N° 1/1009 (01-02/2009) . - p. 39-47[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 011058 - Périodique Bibliothèque principale Documentaires Disponible Thermo-responsive Metal-chelating Surfactants : Properties and Use in Cloud Point Extraction of Uranyl Nitrate / S. Prévost in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 46, N° 2/2009 (02-03/2009)
[article]
Titre : Thermo-responsive Metal-chelating Surfactants : Properties and Use in Cloud Point Extraction of Uranyl Nitrate Type de document : texte imprimé Auteurs : S. Prévost, Auteur ; H. Coulombeau, Auteur ; K. Baczko, Auteur ; L. Berthon, Auteur ; N. Zorz, Auteur ; H. Desvaux, Auteur ; F. Testard, Auteur ; Th. Zemb, Auteur ; C. Larpent, Auteur Année de publication : 2009 Article en page(s) : p. 100-104 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Surfactants Tags : Thermo-responsive surfactants Metal binding Uranyl complex Cloud point extraction Nonionic Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : The properties of new thermo-responsive functional surfactants, capable of forming a metal chelate, synthesized by grafting a diamide group (amino-acid residue) to the tip hydrophilic endgroup or in a branched position to polyoxyethylene nonionic surfactants [CiEj: CiH2i+1(OCH2CH2)jOH)], are studied. Their use in cloud point extraction of uranyl nitrate is tested. The reversible temperature-dependent behavior of classical non-ionic surfactants associated to phase separation of micellar solutions known as clouding behavior is exploited for separation based on cation specific binding to the chelating group. The functional surfactants under investigation combine surface-active properties and characteristic thermoreversible behavior with a capacity to bind uranyl cation. The influence of the complexation on the cloud points of functional surfactants is determined. The chelating surfactants are found efficient for the cloud point extraction of uranyl nitrate at low surfactant-to-uranyl ratio. These new thermoresponsive surfactants with chelating properties hold most promise for the development of new solvent free extraction processes. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4578
in TENSIDE, SURFACTANTS, DETERGENTS > Vol. 46, N° 2/2009 (02-03/2009) . - p. 100-104[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 011181 - Périodique Bibliothèque principale Documentaires Disponible Phase Separation Study of a Surface-Active Drug, Promazine Hydrochloride, in Presence of Surfactants and Ureas / Kabir-ud-Din in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 45, N° 3/2008 (05-06/2008)
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Titre : Phase Separation Study of a Surface-Active Drug, Promazine Hydrochloride, in Presence of Surfactants and Ureas Type de document : texte imprimé Auteurs : Kabir-ud-Din, Auteur ; Mohd Akram, Auteur ; A. Z. Naqvi, Auteur ; Mohd. D. A. Al-Ahmadi, Auteur Année de publication : 2008 Article en page(s) : p. 131-136 Note générale : Bibliogr. Langues : Anglais (eng) Tags : Tricyclic phenothiazine drug Promazine hydrochloride Cloud point Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : As clouding in drugs causes high concentration of drug at a particular site which may prove harmful to the body, the clouding behaviour of a tricyclic phenothiazine drug promazine hydrochloride (PMZ) in aqueous solutions has been studied in the presence of surfactants and ureas. The cloud point (CP) decreases with increase in pH due to deprotonation of the drug molecules. Addition of non-ionic and cationic (conventional as well as Gemini) surfactants increased the CP whereas anionic surfactants showed a peaked profile. The urea family additives influenced the CP in both ways that depended whether they contain >C=O or >C=S moiety: the former interacts with the micelles and lowers the CP while the latter (due to its electropositive character) may not interact and hence CP increases. Dye solubilization results indicate micellar growth with the addition of surfactants in PMZ solutions. The results are interpreted taking cognizance of mixed micelle formation, hydrophobic interactions, and/or change in solvent structure. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3046
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Code-barres Cote Support Localisation Section Disponibilité 010305 - Périodique Bibliothèque principale Documentaires Disponible