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Adsorption of Surfactant
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Mark M Richter – One of the best experts on this subject based on the ideXlab platform.
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effects of poly ethylene glycol tert octylphenyl ether on tris 2 phenylpyridine iridium iii tripropylamine electrochemiluminescence
Analytical Chemistry, 2003Co-Authors: Christopher Cole, Brian D Muegge, Mark M RichterAbstract:The effects of the nonionic Surfactant Triton X-100 (poly(ethylene glycol) tert-octylphenyl ether) on the properties of tris(2-phenylpyridine)iridium(III) (Ir(ppy)3, where ppy = 2-phenylpyridine, electrochemiluminescence (ECL) have been investigated. Anodic oxidation of Ir(ppy)3 produces ECL in the presence of tri-n-propylamine (TPrA) in aqueous Surfactant solution. Increases in ECL efficiency (≥10-fold) and TPrA oxidation current (≥2.0-fold) have been observed in Surfactant media. The data support Adsorption of Surfactant on the electrode surface, thus facilitating TPrA and Ir(ppy)3 oxidation and leading to higher ECL efficiencies.
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Surfactant Chain Length Effects on the Light Emission of Tris(2,2‘-bipyridyl)ruthenium(II)/Tripropylamine Electrogenerated Chemiluminescence
Analytical Chemistry, 2001Co-Authors: Brigitte Factor, Brian D Muegge, Scott Workman, Ed Bolton, Mark M RichterAbstract:The effects of nonionic Surfactant chain length on the properties of tris(2,2‘-bipyridyl)ruthenium(II) (Ru(bpy)32+ where bpy = 2,2‘-bipyridine) electrochemiluminescence (ECL) have been investigated. The electrochemistry, photophysics, and ECL of Ru(bpy)32+ in the presence of a series of nonionic Surfactants are reported (Triton X-100, 114, 165, 405, 305, and 705−70). These Surfactants differ in the number of poly(ethylene oxide) units incorporated into the Surfactant molecule. The anodic oxidation of Ru(bpy)32+ produces ECL in the presence of tri-n-propylamine (TPrA) in aqueous Surfactant solution. Increases in ECL efficiency (≥5-fold) and TPrA oxidation current (≥2-fold) have been observed in Surfactant media. Slight decreases in ECL intensity are observed as the chain length of the nonionic Surfactant increases. The data supports Adsorption of Surfactant on the electrode surface, thus facilitating TPrA and Ru(bpy)32+ oxidation and leading to higher ECL efficiencies.
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Surfactant chain length effects on the light emission of tris 2 2 bipyridyl ruthenium ii tripropylamine electrogenerated chemiluminescence
Analytical Chemistry, 2001Co-Authors: Brigitte Factor, Brian D Muegge, Scott Workman, Ed Bolton, Mark M RichterAbstract:The effects of nonionic Surfactant chain length on the properties of tris(2,2‘-bipyridyl)ruthenium(II) (Ru(bpy)32+ where bpy = 2,2‘-bipyridine) electrochemiluminescence (ECL) have been investigated. The electrochemistry, photophysics, and ECL of Ru(bpy)32+ in the presence of a series of nonionic Surfactants are reported (Triton X-100, 114, 165, 405, 305, and 705−70). These Surfactants differ in the number of poly(ethylene oxide) units incorporated into the Surfactant molecule. The anodic oxidation of Ru(bpy)32+ produces ECL in the presence of tri-n-propylamine (TPrA) in aqueous Surfactant solution. Increases in ECL efficiency (≥5-fold) and TPrA oxidation current (≥2-fold) have been observed in Surfactant media. Slight decreases in ECL intensity are observed as the chain length of the nonionic Surfactant increases. The data supports Adsorption of Surfactant on the electrode surface, thus facilitating TPrA and Ru(bpy)32+ oxidation and leading to higher ECL efficiencies.
Valentin B. Fainerman – One of the best experts on this subject based on the ideXlab platform.
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New view of the Adsorption of Surfactants at water/alkane interfaces – Competitive and cooperative effects of Surfactant and alkane molecules.
Advances in colloid and interface science, 2020Co-Authors: Valentin B. Fainerman, Aliyar Javadi, Eugene V. Aksenenko, N. Mucic, Volodymyr I. Kovalchuk, Libero Liggieri, Francesca Ravera, G. Loglio, Alexander V. Makievski, Emanuel SchneckAbstract:Abstract The theoretical description of the Adsorption of Surfactants at interfaces between aqueous solutions and oil was based over a very long time on models derived for the solution/air interface. Thus, most of the experimentally observed peculiarities could not be specifically considered but were merely interpreted in terms of a penetration of oil molecules into the alkyl chain layer of the adsorbed Surfactant molecules. These penetrating oil molecules enhance the Surfactant Adsorption as compared to the water/air interface. Later on, for the special situations at water/oil interfaces a competitive Adsorption of Surfactant and oil molecules was postulated, allowing a much better description of experimental data. This picture, however, was unable to explain why the interfacial tension of the water/oil interface decreases very quickly when extremely small amounts of Surfactants are added to the water. This effect cannot be of competitive nature, but a cooperativity of Surfactant and oil molecules forming a mixed Adsorption layer is required instead. This cooperative effect means that already few Surfactant molecules adsorbed at the interface can induce a significant ordering of oil molecules in the interfacial layer. This new interfacial structure, in turn, attracts further Surfactant molecules to adsorb. Improving the theoretical description of experimental data was finally achieved by applying suitable Adsorption models for the two adsorbing compounds, i.e. a Frumkin Adsorption model for the oil molecules and a Langmuir, Frumkin, or reorientation model for the adsorbing Surfactant molecules. Here, the progress in modelling Surfactant Adsorption at water/oil interfaces is discussed mainly for the homologous series of the cationic Surfactants CnTAB, of the anionic Surfactant SDS, and members of the homologous series of the non-ionic Surfactants CnDMPO at water/alkane interfaces.
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Surface Tension and Adsorption Studies by Drop Profile Analysis Tensiometry
Journal of Surfactants and Detergents, 2017Co-Authors: T. Kairaliyeva, Nenad Mucic, Eugene V. Aksenenko, Valentin B. Fainerman, A. V. Makievski, Reinhard MillerAbstract:Surface tension and dilational viscoelasticity of solutions of various Surfactants measured with bubble and drop profile analysis tensiometry are discussed. The study also includes experiments on the co-Adsorption of Surfactant molecules from a solution drop and alkane molecules from saturated alkane vapor phase. Using experimental data for 12 Surfactants with different surface activities, it is shown that depletion due to Adsorption of Surfactant from the drop bulk can be significant. An algorithm is proposed quantitatively to take into consideration the depletion effect which is required for a correct description of the co-Adsorption of alkanes on the solution drop surface and the correct analysis of experimental dynamic surface tension data to determine the Adsorption mechanism. Bubble and drop profile analysis tensiometry is also the method of choice for measuring the dilational viscoelasticity of the adsorbed interfacial layer. The same elasticity moduli are obtained with the bubble and drop method only when the equilibrium surface pressures are sufficiently small (Π
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Effect of partial vapor pressure on the co-Adsorption of Surfactants and hexane at the water/hexane vapor interface
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2015Co-Authors: Nenad Mucic, N. Moradi, Aliyar Javadi, Eugene V. Aksenenko, Valentin B. Fainerman, Reinhard MillerAbstract:The Adsorption of Surfactants from aqueous solution at the water/air interface is changed when the air phase contains hexane vapor. This co-Adsorption of Surfactant and hexane depends on the hexane vapor pressure. A thermodynamic model developed for the Adsorption of Surfactant mixtures can be adapted to the present situation. The Surfactants studied were SDS, C12TAB and C12DMPO, and the dependence of their Adsorption characteristics on the partial hexane vapor pressure was determined. The co-Adsorption of hexane from the vapor phase increases the surface activity of the adsorbing Surfactants.
Reinhard Miller – One of the best experts on this subject based on the ideXlab platform.
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Surface Tension and Adsorption Studies by Drop Profile Analysis Tensiometry
Journal of Surfactants and Detergents, 2017Co-Authors: T. Kairaliyeva, Nenad Mucic, Eugene V. Aksenenko, Valentin B. Fainerman, A. V. Makievski, Reinhard MillerAbstract:Surface tension and dilational viscoelasticity of solutions of various Surfactants measured with bubble and drop profile analysis tensiometry are discussed. The study also includes experiments on the co-Adsorption of Surfactant molecules from a solution drop and alkane molecules from saturated alkane vapor phase. Using experimental data for 12 Surfactants with different surface activities, it is shown that depletion due to Adsorption of Surfactant from the drop bulk can be significant. An algorithm is proposed quantitatively to take into consideration the depletion effect which is required for a correct description of the co-Adsorption of alkanes on the solution drop surface and the correct analysis of experimental dynamic surface tension data to determine the Adsorption mechanism. Bubble and drop profile analysis tensiometry is also the method of choice for measuring the dilational viscoelasticity of the adsorbed interfacial layer. The same elasticity moduli are obtained with the bubble and drop method only when the equilibrium surface pressures are sufficiently small (Π
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Effect of partial vapor pressure on the co-Adsorption of Surfactants and hexane at the water/hexane vapor interface
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2015Co-Authors: Nenad Mucic, N. Moradi, Aliyar Javadi, Eugene V. Aksenenko, Valentin B. Fainerman, Reinhard MillerAbstract:The Adsorption of Surfactants from aqueous solution at the water/air interface is changed when the air phase contains hexane vapor. This co-Adsorption of Surfactant and hexane depends on the hexane vapor pressure. A thermodynamic model developed for the Adsorption of Surfactant mixtures can be adapted to the present situation. The Surfactants studied were SDS, C12TAB and C12DMPO, and the dependence of their Adsorption characteristics on the partial hexane vapor pressure was determined. The co-Adsorption of hexane from the vapor phase increases the surface activity of the adsorbing Surfactants.
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Adsorption of Alkyltrimethylammonium Bromides at Water/Alkane Interfaces: Competitive Adsorption of Alkanes and Surfactants
Langmuir, 2013Co-Authors: Valentin B. Fainerman, Nenad Mucic, Eugene V. Aksenenko, V. Pradines, Reinhard MillerAbstract:The Adsorption of members of the homologous series of alkyl trimethylammonium bromides (CnTAB) is studied at water/alkane interfaces by drop profile analysis tensiometry. The results are discussed in terms of a competitive Adsorption process of alkane and Surfactant molecules. A thermodynamic model, derived originally for the Adsorption of Surfactant mixtures, is adapted such that it describes a competitive Adsorption of the Surfactant molecules from the aqueous phase and alkane molecules from the oil phase. This new model involves the interspecies attraction coefficient, which mutually increases the Adsorption activities of the alkane and CnTAB. The effects of the alkyl chain length n of CnTABs and the influence of the number of C atoms in the alkane chain are discussed, and the physical quantities are compared to those determined at the aqueous solution/air interface. The new theoretical model for aqueous solution/oil interfaces is also compared to a theory that does not consider the Adsorption of alkan…