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Synthesis, characterization and thermodynamic parameters of anionic gemini surfactants with different spacer groups / H. El-sharkawy Ali in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 44, N° 5/2007 (10-11/2007)
[article]
Titre : Synthesis, characterization and thermodynamic parameters of anionic gemini surfactants with different spacer groups Type de document : texte imprimé Auteurs : H. El-sharkawy Ali, Auteur Année de publication : 2007 Article en page(s) : p. 281-286 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Adsorption
Caractérisation
Micelles
Surfactants -- Synthèse
Tension superficielle
ThermodynamiqueTags : 'Gemini surfactants' 'Critical micelle concentration' 'Surface tension kinetic micellization' 'Thermodynamics of Adsorption Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : The aim of this work is to investigate the micellization and adsorption thermodynamics (DmicH°, DmicG°, DmicS°, DadsH°, DadsG°, DadsS°) for three novel anionic Gemini surfactants with the same structure except the spacer length of the polymethylene chain have been synthesized based on nonylphenol (NP). The surface tension at cmc (Ycmc) and critical micelle concentration (cmc) of the surfactants in aqueous solutions have been investigated. C20 values (surfactant concentration in the solution phase that will reduce the surface tension of the solvent by 20 mNm–1) were also obtained. The critical micellar concentration (cmc) and the minimum average area per surfactant molecule (Amin) at the air-water interface of Gemini surfactant decrease with increasing number of methylene moieties in the spacer and, consequently, with the enhanced hydrophilic character of the molecule. The results were discussed with particular emphasis on the effect of the length spacer on the hydrophilic character of the spacer group. The surface studies of the molecules confirm that the exothermic values of the differential enthalpy of micellization (DmicH°) decrease as the methylene moieties are lengthened. Moreover, the values of the free energy (DmicG°) and entropy (DmicS°) of micellization indicate an entropy driven phenomenon for all surfactants. The effect of length spacer on surfactant adsorption for Gemini surfactants was utilized to calculate such thermodynamic parameters as the free energy of adsorption (DadsG°) and the heat of adsorption (DadsH°). The low value of DadsH° is an evidence for the physical adsorption of anionic surfactants. The relatively large value of entropic contribution (TDadsS°) indicates that the adsorption of anionic surfactants is entropically governed. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3204
in TENSIDE, SURFACTANTS, DETERGENTS > Vol. 44, N° 5/2007 (10-11/2007) . - p. 281-286[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 008403 - Périodique Bibliothèque principale Documentaires Disponible Synergism in mixed anionic–amphoteric surfactant solutions: influence of anionic surfactant chain length / R. Abdel-Rahem in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 46, N° 5/2009 (09-10/2009)
[article]
Titre : Synergism in mixed anionic–amphoteric surfactant solutions: influence of anionic surfactant chain length Type de document : texte imprimé Auteurs : R. Abdel-Rahem, Auteur Année de publication : 2009 Article en page(s) : p. 298-305 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Surfactants Tags : Surfactant amphotérique Concentration critique Micelle Paramètres interaction Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : The influence of chain length on the composition of mixed micelles in binary mixtures of N,N-dimethyldodecylamine oxide (DDAO) and sodium decyl-, sodium dodecyl-and sodium tetradecylsulfate (abbreviated as SDeS, SDS ans STS, respectively) has been determined at 30°C. From the surface tension measurements, the critical micelle concentration (cmc) data were measured as a function of mixing composition. Cmc-values were then analyzed according to regular solution model. The composition of mixed micelles, the interaction parameter (B) and the activity coefficients were evaluated from the regular solution model for the all anionic-amphoteric mixed systems. The interaction parameter values indicated a synergistic interaction between DDAO and the three anionic surfactants at all mole fractions to be due to an overall attractive interaction in the mixed micelles. The strength of the interaction between tha amphoteric surfactant and the sodium alkyl sulfate in three mixed systems obeys the following order : SDeS/DDAO>SDS>DDAO>STS>DDAO suggesting that the decrease in the length of anionic surfactant alkyl chain results in a stronger interaction with DDAO. On the other hand, the viscosity data reveals a viscosity increasing trend of STS/DDAO>SDS/DDAO>SDeS/DDAO. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=6251
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Code-barres Cote Support Localisation Section Disponibilité 011608 - Périodique Bibliothèque principale Documentaires Disponible Basics, ingredients, detergents, product safety and sustainability / Hermann G. Hauthal in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 45, N° 1/2008 (01-02/2008)
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Titre : Basics, ingredients, detergents, product safety and sustainability : Third european detergents conference report Type de document : texte imprimé Auteurs : Hermann G. Hauthal, Auteur Année de publication : 2008 Article en page(s) : p. 30-42 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Adsorption
Détergents
Micelles
Mousse (chimie)Tags : Nanotransporters Adsorption Foam Block copolymers micelle Natural amphiphiles Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : The Third European Detergents Conference embedded in the 54th SEPAWA Congress took place in the Congress Centrum Würzburg, Bavaria, from October 10th - 12th 2007. About 140 attendees from more than 20 countries visited this event - this was am increase od 5.6% compared to 2006 En ligne : https://drive.google.com/file/d/12sXqwNrWd3M69eQsX1T_nNXBf3cDMY_U/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3054
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Code-barres Cote Support Localisation Section Disponibilité 009761 - Périodique Bibliothèque principale Documentaires Disponible Study on the Synthesis and Surface Activities of Disodium of Mono-Alkyl Polyoxyethylene Ether Citrate / Z.-C. Zhou in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 44, N° 5/2007 (10-11/2007)
[article]
Titre : Study on the Synthesis and Surface Activities of Disodium of Mono-Alkyl Polyoxyethylene Ether Citrate Type de document : texte imprimé Auteurs : Z.-C. Zhou, Auteur ; Y.-M. Cheng, Auteur ; G.-J. Sun, Auteur ; X.-Q. Yang, Auteur Année de publication : 2007 Article en page(s) : p. 287-297 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Anhydrides
Citrique, AcideL'acide citrique est un acide alpha hydroxylé de formule C6H8O7.
Il joue un rôle central dans le métabolisme de tous les organismes vivants et tient son nom de son origine; le citron.
L'acide citrique est biodégradable et n'est pas toxique pour l'homme ni pour l'environnement. Cependant, comme tout acide, il est irritant et peut provoquer des brûlures s'il entre en contact prolongé avec des muqueuses.
À pH physiologique, il est présent sous forme de sa base conjuguée, le citrate, qui est un chélateur de l'ion calcium dans le sang.
Esterification
Micelles
Polyéthylène glycolTags : Citric anhydride Monester citric acid Critical micelle concentration Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : A synthetic process of Disodium of Mono-Alkyl polyoxyethylene Ether Citrate was developed in this paper. The structure of intermediate and products were indicated by infrared spectroscopy. The physico-chemical properties of aqueous solution of products were also investigated. The results show that products are excellent emulsifiers, with the low surface tension in 27–30 mN/ m and good wetting power, and possess different foaming behavior in hard water and distilled water. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3205
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Code-barres Cote Support Localisation Section Disponibilité 008403 - Périodique Bibliothèque principale Documentaires Disponible Biologically Active Tin Compounds Based on Aziridine and Azepane Derivatives / H. El-sharkawy Ali in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 45, N° 2/2008 (03-04/2008)
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Titre : Biologically Active Tin Compounds Based on Aziridine and Azepane Derivatives Type de document : texte imprimé Auteurs : H. El-sharkawy Ali, Auteur Année de publication : 2008 Article en page(s) : p. 76-80 Note générale : Bibliogr. Langues : Anglais (eng) Tags : Nitrogen heterocycles Aziridine Azepane derivatives Critical micelle concentration Surface tension Antimicrobial activity Surfactants Index. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : Four of new tin(IV) compounds derived from aziridine and azepane substituents have been synthesized and characterization by elemental microanalysis, atomic absorption, FT-IR and 1H-NMR spectroscopy. These tin-derived compounds exhibited biocidal activities on four different microorganisms: Escherichia coli, Staphylococcus aureus, Candida albicans and Aspergillus niger. The use of common and effective biocides depends on the surfactant molecules. On this basis, surface tension measurements were used to determine the critical micellar concentration (cmc), the minimum average area per surfactant molecule (Amin) and the surface excess concentration (L8). A direct relationship has found between the antimicrobial efficacy and L8. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3033
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Code-barres Cote Support Localisation Section Disponibilité 009993 - Périodique Bibliothèque principale Documentaires Disponible Micellization of cetyltributylphosphonium bromide in some binary aqueous solvents mixtures / S. Tiwari in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 45, N° 5/2008 (09-10/2008)
PermalinkOn the presence of loops in linear self-assembling systems. Statistical methods and Brownian dynamics / Martin Kröger in LES CAHIERS DE RHEOLOGIE, Vol. XV, N° 4 (10/1997)
PermalinkStudy of the cloud point of C12EO6 and C12EO8 nonionic surfactants : effect of additives / Moussa Alibrahim in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 49, N° 4 (07-08/2012)
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