Protonation equilibria shifts in aqueous solutions of dodecyl sulfates

Dorion, F.; Charbit, G.; Gaboriaud, René

doi:10.1016/0021-9797(84)90005-5

Cited by 18 publications

(5 citation statements)

References 35 publications

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“…The theoretical analysis of the experimental data is as varied as the experimental approaches [25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

“…A wide range of experimental approaches, such as pH measurements of aqueous phase in the presence of micelles and weak acids, degree of indicator dissociation estimated spectroscopically, 13 C NMR observations in labeled acids, and kinetic effect of micelles on pH-dependent rates, have been used to estimate local or interfacial proton concentrations [H + ] I and calculate local pHs at micellar and membrane surfaces, pH I [1,[25][26][27]. The theoretical analysis of the experimental data is as varied as the experimental approaches [25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

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pH at the micellar interface: Synthesis of pH probes derived from salicylic acid, acid–base dissociation in sodium dodecyl sulfate micelles, and Poisson–Boltzmann simulation

Souza

Zanette

Kawanami

et al. 2006

Journal of Colloid and Interface Science

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“…The theoretical analysis of the experimental data is as varied as the experimental approaches [25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

pH at the micellar interface: Synthesis of pH probes derived from salicylic acid, acid–base dissociation in sodium dodecyl sulfate micelles, and Poisson–Boltzmann simulation

Souza

Zanette

Kawanami

et al. 2006

Journal of Colloid and Interface Science

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“…The modification of the equilibrium constants and rate of reaction which occurs when a dispersed system is introduced into a reaction medium is a well-known phenomenon which has been much investigated and reported in the literature over the past few years. The work involves, essentially, micellar systems using both neutral and charged tensioactives, − and also complex mixtures which give microemulsions. − …”

Section: Introductionmentioning

confidence: 99%

Thermodynamic and Kinetic Approach of the Reactivity in Micellar Media. Reaction of 1,3,5-Trinitrobenzene upon Hydroxide Ion in Aqueous Solutions of Cationic Surfactants

et al. 2001

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The kinetics of the reaction of OHwith 1,3,5-trinitrobenzene in the presence of dodecyl and hexadecyltrimethylammonium bromide have been studied. The micellar effects on this reaction have been modelized with the help of a new thermodynamic and kinetic analysis. This modelization has been based on a profitable approach proposed by De Donder and Defay which is well suited to the kinetics in dispersed medium. The chemical exchange rates σ V 0 and b V 0 , which are, respectively, the micellar and the bulk exchange rates, have been determined. This report also reveals that the acceleration of chemical reactions is mainly due not only to a large increase of the chemical exchange rate on the micellar aggregates but also to the high stabilization of the activated complex.

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“…From these positions, one may consider data for a variety of compounds: nitrophenols [148], hydroxyanthraquinones [149], substituted diarylamines [150], fluorescein dyes [17,18,132,134], rhodamines [31,[151][152][153][154][155], azo dyes [156]; acridines [157], and many other indicators [13,19,97,133,[140][141][142][143][144][145][146][147][158][159][160][161][162][163][164][165][166].…”

Section: Acid-base Indicators As Useful Tools For Studying Micelles 6...mentioning

confidence: 99%

Solvatochromic and Acid–Base Molecular Probes in Surfactant Micelles: Comparison of Molecular Dynamics Simulation with the Experiment

Mchedlov‐Petrossyan

Farafonov

Lebed

2023

Liquids

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This article summarizes a series of seventeen publications by the authors devoted to molecular dynamics modeling of various indicator dyes (molecular probes) enclosed in surfactant micelles. These dyes serve as generally recognized tools for studying various types of organized solutions, among which surfactant micelles in water are the simplest and most explored. The modeling procedure involves altogether 50 to 95 surfactant molecules, 16 to 28 thousand water molecules, and a single dye molecule. The presentation of the simulation results was preceded by a brief review of the state of experimental studies. This article consists of three parts. First, despite numerous literature data devoted to modeling the micelles itself, we decided to revisit this issue. The structure and hydration of the surface of micelles of surfactants, first of all of sodium n-dodecylsulfate, SDS, and cetyltrimethylammonium bromide, CTAB, were studied. The values of the electrical potential, Ψ, were estimated as functions of the ionic strength and distance from the surface. The decrease in the Ψ value with distance is gradual. Attempts to consider both DS− and CTA+ micelles in water without counterions result in a decay into two smaller aggregates. Obviously, the hydrophobic interaction (association) of the hydrocarbon tails balances the repulsion of the charged headgroups of these small “bare” micelles. The second part is devoted to the study of seven pyridinium N-phenolates, known as Reichardt’s dyes, in ionic micelles. These most powerful solvatochromic indicators are now used for examining various colloidal systems. The localization and orientation of both zwitterionic and (colorless) cationic forms are generally consistent with intuitive ideas about the hydrophobicity of substituents. Hydration has been quantitatively described for both the dye molecule as a whole and the oxygen atom. A number of markers, including the visible absorption spectra of Reichardt’s dyes, enable assuming a better hydration of the micellar surface of SDS than that of CTAB. However, our data show that it is more correct to speak about the more pronounced hydrogen-bonding ability of water molecules in anionic micelles than about better hydration of the SDS micelles as compared to CTAB ones. Finally, a set of acid–base indicators firmly fixed in the micellar pseudophase were studied by molecular dynamics. They are instruments for estimating electrostatic potentials of micelles and related aggregates as Ψ= 2.303RTF−1 (pKai − pKaapp), where pKai and pKaapp are indices of so-called intrinsic and apparent dissociation constants. In this case, in addition to the location, orientation, and hydration, the differences between values of pKaapp and indices of the dissociation constants in water were estimated. Only a semi-quantitative agreement with the experimental data was obtained. However, the differences between pKaapp of a given indicator in two micellar solutions do much better agree with the experimental data. Accordingly, the experimental Ψ values of ionic micelles, as determined using the pKaapp in nonionic micelles as pKai, are reproduced with reasonable accuracy for the corresponding indicator. However, following the experimental data, a scatter of the Ψ values obtained with different indicators for given micelles is observed. This problem may be the subject of further research.

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Protonation equilibria shifts in aqueous solutions of dodecyl sulfates

Cited by 18 publications

References 35 publications

pH at the micellar interface: Synthesis of pH probes derived from salicylic acid, acid–base dissociation in sodium dodecyl sulfate micelles, and Poisson–Boltzmann simulation

pH at the micellar interface: Synthesis of pH probes derived from salicylic acid, acid–base dissociation in sodium dodecyl sulfate micelles, and Poisson–Boltzmann simulation

Thermodynamic and Kinetic Approach of the Reactivity in Micellar Media. Reaction of 1,3,5-Trinitrobenzene upon Hydroxide Ion in Aqueous Solutions of Cationic Surfactants

Solvatochromic and Acid–Base Molecular Probes in Surfactant Micelles: Comparison of Molecular Dynamics Simulation with the Experiment

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