Sodium Dodecyl Sulfate Micelle Solutions Research Articles

DiPyMe in SDS Micelles: Artifacts and Their Implications in the Interpretation of Micellar Properties.

This study provides experimental evidence that di(1-pyrenylmethyl) ether or DiPyMe, a well-known fluorescent probe employed to determine the microviscosity of surfactant or polymeric micelles, is being hydrolyzed in the presence of water upon UV irradiation. This effect was established from a careful analysis of the fluorescence spectra and decays acquired with aqueous solutions of DiPyMe dissolved in micelles of sodium dodecyl sulfate (SDS). The size of the SDS micelles could be adjusted from an aggregation number (N(agg)) of 70 to 172 by increasing the ionic strength of the aqueous solution from 0.0 to 0.5 M NaCl. The hydrolysis of DiPyMe was much reduced in the larger SDS micelles. While the degradation of DiPyMe in aqueous solutions of SDS micelles affected the analysis of the fluorescence spectra, model-free analysis (MFA) of the fluorescence decays of DiPyMe could reliably retrieve the rate constant ⟨k⟩ of excimer formation for DiPyMe. After calibration with mixtures of organic solvents of known macroscopic viscosity, the ⟨k⟩ values obtained for DiPyMe yielded the microviscosity (μη) of the SDS micelles as a function of salt concentration. The μη was found to increase from 4.0 to 8.8 mPa·s as the salt concentration increased from 0.0 to 0.5 M. This study demonstrated that, regardless of the problem of its hydrolysis that jeopardizes its use in steady-state fluorescence experiments, DiPyMe remains an extremely valuable probe for describing the microviscosity of hydrophobic domains in aqueous solution as long as its decays are analyzed with a model that accounts for the presence of degradation products as the MFA does.

NMR structure of the Arctic mutation of the Alzheimer’s Aβ(1–40) peptide docked to SDS micelles

The “Arctic” point mutation of the Alzheimer’s amyloid β-peptide is a rare mutation leading to an early onset of Alzheimer’s disease. The peptide may interact with neuronal membranes, where it can provide its toxic effects. We used 2D NMR spectroscopy to investigate the conformation of the “Arctic” mutant of Aβ1–40 Alzheimer’s amyloid peptide in sodium dodecyl sulfate micelle solutions, which are the type of amphiphilic structures mimicking some properties of biomembranes. The study showed that the Arctic mutant of Aβ1–40 interacts with the surface of SDS micelles mainly through the Leu17–Asn27 310-helical region, while the Ile31–Val40 region is buried in the hydrophobic interior of the micelle. In contrast, wild-type Aβ1–40 interacts with SDS micelles through the Lys16–Asp23 α-helical region and Gly29–Met35. Both the Arctic mutant and the wild-type Aβ1–40 peptides interactions with SDS micelles are hydrophobic in nature. Aβ peptides are thought to be capable of forming pores in biomembranes that can cause changes in neuronal and endothelial cell membrane permeability. It has also been shown that Aβ peptides containing the “Arctic” mutation are more neurotoxic and aggregate more readily than the wild-type Aβ peptides at physiological conditions. Here, we propose that the extension of the helical structure of Leu17–Asn27 and a high aliphaticity (neutrality) of the C-terminal region in the Arctic Aβ peptides are consistent with the idea that formation of ion-permeable pores by Aβ oligomers may be one of prevailing mechanisms of a larger neuronal toxicity of the Arctic Aβ compared to the wild-type Aβ peptides, independent of oxidative damage and lipid peroxidation.

Experimental and theoretical investigation of the depletion and structural forces produced by ionic micelles

The technique of colloid probe atomic force microscopy was used to measure the force profile between a silica particle and a flat silica plate in solutions of tetradecyltrimethylammonium bromide (C14TAB) and sodium dodecyl sulfate (SDS) at varying concentrations. With increasing surfactant concentration the onset of a depletion well and structural forces was observed. The measured results were compared to the predicted results of the model of Walz and Sharma [26] for hard, charged, spherical depletants. For C14TAB the measured depletion force was substantially smaller in magnitude than that predicted by this model. In solutions of SDS micelles, a similar overestimation of the depletion force was observed but not to the same degree as for the C14TAB solutions. It was found that by reducing the magnitude of the electrostatic repulsive interactions in the system via lowering the effective surface potentials, the measured force profiles could be accurately matched. These results suggest that modeling ionic micelles as simple hard, charged spheres may not be appropriate and that the level of deviation from such a modeling approach depends on the specific properties of each type of micelle.

Mechanistic information from volume profiles for water exchange and complex-formation reactions of aquated Ni(II). pH, buffer and medium effects

Rate and activation parameters for the complex-formation reaction of Ni(2+) with 4-(2-pyridylazo)-N,N-dimethyl aniline (PADA) were studied as a function of pH in different buffers in both aqueous and sodium dodecyl sulfate (SDS) micelle solutions. In aqueous Tris buffer solution, the forward and backward rate constants increased with increasing pH, while the complex-formation constant decreased due to a larger increase in the backward rate constant. The activation entropy, DeltaS(#), and activation volume, DeltaV(#), changed with increasing pH from positive to negative values, suggesting an apparent changeover from a dissociative to a more associative mechanism. Complex-formation reactions with 2,2'-bipyridine in Tris buffer showed almost no increase in the forward and backward rate constants on increasing the pH, but the DeltaS(#) and DeltaV(#) values became more negative. N-ethylmorpholine buffer showed no pH effect on the rate constants and activation parameters. Water exchange reactions of aquated Ni(2+) were also studied as a function of pH under the same conditions. The reported rate and activation parameters for water exchange in Tris and N-ethylmorpholine buffers are consistent with those found for the complex-formation reactions of Ni(2+) with PADA. The observed pH and buffer effects for both the complex-formation and water exchange reactions of aquated Ni(2+) can be accounted for in terms of the formation of a Ni(2+)-Tris complex in Tris buffer and general base catalysis by the buffer components. In SDS micelle solution, the complex-formation reaction with PADA was much faster than in aqueous solution, but the increase in rate constant with increasing pH was less significant, while DeltaS(#) and DeltaV(#) became more positive, pointing to a more dissociative mechanism. For SDS micelle solutions there was no effect on the water exchange rate constant or activation volume. Mechanistic interpretations are offered for all observed pH, buffer and medium effects.

Molecular Dynamics Simulation of Effect of Salt on the Compromise of Hydrophilic and Hydrophobic Interactions in Sodium Dodecyl Sulfate Micelle Solutions

The presence of salt has a profound effect on the size, shape and structure of sodium dodecyl sulfate (SDS) micelles. There have been a great number of experiments on SDS micelles in the presence and absence of salt to study this complex problem. Unfortunately, it is not clear yet how electrolyte ions influence the structure of micelles. By describing the compromise between dominant mechanisms, a simplified atomic model of SDS in presence of salt has been developed and the molecular dynamics (MD) simulations of two series of systems with different concentrations of salt and charges of ion have been performed. Polydispersity of micelle size is founded at relatively high concentration of SDS and low charge of cation. Although the counter-ion pairs with head groups are formed, the transition of micelle shape is not observed because the charge of cation is not enough to neutralize the polar of micelle surface.

Electrochemical Behavior of Cationic‐Anionic Surfactant Solutions by Cyclic Voltammetry

The electrochemical behavior of cationic tetradecyltrimethylammonium bromide (TTABr), anionic sodium dodecylsulfate (SDS), cationic‐anionic (catanionic) mixed surfactant and self‐assembled solutions at Pt wire electrode has been studied by cyclic voltammetry (CV). On the basis of the cyclic voltammograms and determining the self‐assembled structures by using freeze‐fracture transmission electron microscopy (FF‐TEM), the mechanisms of the electrochemical reactions near the electrode for the two surfactant self‐assembled solutions, i.e., micelles and vesicles, are presented. When mixing TTABr and SDS, at the right mixing ratio of TTABr:SDS, vesicles are established spontaneously. The redox behavior of two vesicle‐phase solutions at a constant total concentration of 25 mmol·L−1 with the ratios of TTABr:SDS 9.35:0.65 of positive charges of bilayer membranes and 1.25:8.75 of negative charges of bilayer membranes are investigated by cyclic voltammetry. These cyclic voltammograms of vesicles with different charges are compared with those of 100 mmol · L−1 TTABr and 100 mmol · L−1 SDS micelle solutions. This CV study on surfactant self‐assembled solutions should open up a new method of study in surfactant science.

Dynamic Fluorescence Probing of the Microenvironment of Sodium Dodecyl Sulfate Micelle Solutions: Surfactant Concentration Dependence and Solvent Isotope Effect

We have studied the surfactant concentration dependence and solvent isotope effect on the slow solvation dynamics and orientational dynamics of solvatochromic coumarin dyes in the aqueous sodium dodecyl sulfate (SDS) micelle solutions using picosecond fluorescence spectroscopy. The solvation time constants for SDS micelle H2O solutions are about 130 ps and 2.5 ns. Both the faster and slower solvation time constants do not depend on the SDS concentration in the range 16.2−810 mM, though the observed solvation component becomes larger with increasing of SDS concentration. The solvation dynamics in SDS micelle D2O solutions is about 1.2 times slower than that in SDS micelle H2O solutions. The retardation of the solvation dynamics in micelle solutions could be due to the slower process of the hydrogen bond dynamics in the hydration layer around the micelle, as well as simple hydrogen-bonding liquids. The surfactant concentration dependence and solvent isotope effect on the orientational dynamics of the fluorescence probe is correlated with those on the solvation dynamics in SDS micelle solutions.

Fluorimetric Determination of Europium Based on the Co-Fluorescence System Eu-Y-Sparfloxacin-SDS

A new room temperature fluorescence enhancement system based on complex formation between europium and sparfloxacin in the presence of yttrium in sodium dodecyl sulfate micelle solution has been discovered. The characteristic fluorescence spectra and the effect factors of the fluorescence intensity of the system have been studied in detail. The study results show that the binary complex formed by europium with sparfloxacin in sodium dodecyl sulfate micelle solution can emit intrinsic fluorescence of the lanthanide ion. In the presence of yttrium, the fluorescence intensity of this system was enhanced about 5-fold compared with that of the system without Y3+. Under the optimum conditions selected, the fluorescence intensity is a linear function of the concentration of europium in the range of 5.0 × 10−11 −5.0 × 10−7 mol L−1, and the detection limit of europium is 1.0×10−13 mol L−1. The system was used for the determination of trace amounts of europium in rare earth samples with satisfactory results.

A novel transfer process of tetra-hydrophenyl porphyrin with two hexadecyl chains in sodium dodecyl sulfate micelle

A pH-controlled transfer process of 5, 15-di(4-hydroxyphenyl)-10, 20-(4-hexadecyloxyphenyl)porphyrin ( P ) in sodium dodecyl sulfate (SDS) micelle was studied in detail by means of UV–Visible spectra and fluorescence spectra. In pH 7.22 SDS micelle solution, P may be protonized and located at the outer surface of micelle. In mild basic condition, the hydrophilic ability of P decreased and the porphyrin moiety may transfer to the inner layer of SDS micelle. In strong basic condition, porphyrin hydrophilic moiety may transfer back to the outer aqueous surface of the micelle. The investigation of kinetics of porphyrin complexing with Cu(II) indicates that metalation of porphyrin in SDS micelle could be controlled by changing pH.

Calorimetric and NMR Investigations of the Micellar Properties of Sodium Dodecyl Sulfate in Aqueous Mixtures of Isomeric Butanediols

The enthalpies (ΔmicH°), entropies (ΔmicS°), and Gibbs energies (ΔmicG°) of micelle formation have been determined for a series of sodium dodecyl sulfate (SDS)/butanediol isomer micelles using isoperibol solution calorimetry. Nuclear magnetic resonance (NMR) paramagnetic relaxation enhancement experiments were used to determine the degree of solubilization of the isomeric butanediols (BTDs) in a 0.100 M solution of SDS micelles. In addition, the manner in which the butanediol cosolvents interact with SDS micelles, as a function of the position of substitution of the hydroxyl groups on the four-carbon backbone, has been examined closely via 13C NMR spectroscopy. All of these results are interpreted in terms of the differences in the interaction of the isomeric butanediols with SDS micelles because of the addition of the second hydroxyl headgroup on the four-carbon backbone of the alcohol, when compared to the well-studied SDS/1-butanol (C4OH) mixed micellar system.

Spectroscopic studies of a phosphoinositide-binding peptide from gelsolin: behavior in solutions of mixed solvent and anionic micelles

The peptide G(150-169) corresponds to a phosphatidylinositol 4,5-bisphosphate (PIP2) and filamentous actin (F-actin) binding site on gelsolin (residues 150-169, with the sequence KHVVPNEVVVQRLFQVKGRR). The conformation of this peptide in trifluoroethanol (TFE) aqueous solution was determined by 1H nuclear magnetic resonance as the first step toward understanding the structural aspects of the interaction of G(150-169) and PIP2. The circular dichroism experiments show that G(150-169) adopts a predominantly alpha-helical form in both 50% TFE aqueous solution and in the presence of PIP2 micelles, therefore establishing a connection between the two conformations. 1H nuclear magnetic resonance experiments of G(150-169) in TFE co-solvent show that the helical region extends from Pro-154 to Lys-166. The amphiphilic nature of this helical structure may be the key to understanding the binding of the peptide to lipids. Sodium dodecyl sulfate micelle solution is used as a model for anionic lipid environments. Preliminary studies of the conformation of G(150-169) in sodium dodecyl sulfate micelle solution show that the peptide forms an alpha-helix similar to but with some structural differences from that in TFE co-solvent. Fluorescence experiments provide evidence of peptide clustering over a narrow range of peptide/PIP2 ratios, which is potentially relevant to the biological function of PIP2.

Coupled tracer diffusion coefficients of solubilizates in ionic micelle solutions from liquid chromatography

The peak-broadening (Taylor dispersion) method is used to measure the diffusion of traces of alcohols (ethanol, n-butanol, n-hexanol, n-octanol, n-decanol) in aqueous solutions of sodium dodecylsulfate micelles at 25°C. A small quantity of each alcohol is injected into a long capillary tube containing a laminar stream of the micelle solution. The tracer diffusion coefficient is calculated from the broadened distribution of the eluted alcohol which is measured by differential refractometry. The fraction of each alcohol that is solubilized by the micelles is estimated from the drop in the diffusion coefficient relative to the value for the free alcohol molecules in pure water. The refractive index profiles across the dispersed samples are analyzed to obtain the cross-diffusion coefficient which gives the coupled flow of sodium dodecylsulfate produced by the tracer diffusion of each alcohol.

ChemInform Abstract: Comparison of the Efficiencies of Several Natural and Synthetic Antioxidants in Aqueous Sodium Dodecyl Sulfate Micelle Solutions

ChemInformVolume 19, Issue 29 Other Subjects ChemInform Abstract: Comparison of the Efficiencies of Several Natural and Synthetic Antioxidants in Aqueous Sodium Dodecyl Sulfate Micelle Solutions W. A. PRYOR, W. A. PRYOR Biodyn. Inst., La. State Univ., Baton Rouge, LA 70803, USASearch for more papers by this authorT. STRICKLAND, T. STRICKLAND Biodyn. Inst., La. State Univ., Baton Rouge, LA 70803, USASearch for more papers by this authorD. F. CHURCH, D. F. CHURCH Biodyn. Inst., La. State Univ., Baton Rouge, LA 70803, USASearch for more papers by this author W. A. PRYOR, W. A. PRYOR Biodyn. Inst., La. State Univ., Baton Rouge, LA 70803, USASearch for more papers by this authorT. STRICKLAND, T. STRICKLAND Biodyn. Inst., La. State Univ., Baton Rouge, LA 70803, USASearch for more papers by this authorD. F. CHURCH, D. F. CHURCH Biodyn. Inst., La. State Univ., Baton Rouge, LA 70803, USASearch for more papers by this author First published: July 19, 1988 https://doi.org/10.1002/chin.198829327Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume19, Issue29July 19, 1988 RelatedInformation

Interaction between an Anionic Surfactant and Some Oil Soluble Azo Dyes at Oil/Water Interface

The adsorption behavior of 5 Azo oil dyes and sodium dodecyl sulfate (SDS) at n-dodecane/water interface were studied. In the case of surfactant free systems, interfacial tension decreased with increasing hydrophilicity of the dye. By applying the Gibbs adsorption equation to the interfacial tension data, the interfacial excesses of Azo oil dyes and SDS were evaluated. The interfacial densities and orientation angles of the dyes at the interface were dependent on the type and replacement positions of the hydrophilic groups.In the presence of a surfactant, both the dye and a strongly hydrophilic group interacted with SDS to a considerable extent.The distribution coefficients of the dyes in n-dodecane and sodium dodecyl sulfate micelle solutions were larger for dyes containing strongly hydrophilic groups than those with weakly hydrophilic groups.

Surfactant-concentration effects in photoinduced electron transfer from pyrene to cupric ions in sodium dodecyl sulfate micelle solutions

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSurfactant-concentration effects in photoinduced electron transfer from pyrene to cupric ions in sodium dodecyl sulfate micelle solutionsTakashi Nakamura, Akira Kira, and Masashi ImamuraCite this: J. Phys. Chem. 1984, 88, 16, 3435–3441Publication Date (Print):August 1, 1984Publication History Published online1 May 2002Published inissue 1 August 1984https://doi.org/10.1021/j150660a014RIGHTS & PERMISSIONSArticle Views43Altmetric-Citations11LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (836 KB) Get e-Alerts

Kinetics of photooxidation of pyrene by cupric ions in sodium dodecyl sulfate micelle solutions

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics of photooxidation of pyrene by cupric ions in sodium dodecyl sulfate micelle solutionsTakashi Nakamura, Akira Kira, and Masashi ImamuraCite this: J. Phys. Chem. 1983, 87, 16, 3122–3125Publication Date (Print):August 1, 1983Publication History Published online1 May 2002Published inissue 1 August 1983https://doi.org/10.1021/j100239a033RIGHTS & PERMISSIONSArticle Views68Altmetric-Citations11LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (459 KB) Get e-Alerts

ChemInform Abstract: ENHANCEMENT OF THE INTERSYSTEM CROSSING OF PYRENE BY METAL IONS IN SODIUM DODECYL SULFATE MICELLE SOLUTIONS

Chemischer InformationsdienstVolume 13, Issue 47 Physical Organic Chemistry ChemInform Abstract: ENHANCEMENT OF THE INTERSYSTEM CROSSING OF PYRENE BY METAL IONS IN SODIUM DODECYL SULFATE MICELLE SOLUTIONS T. NAKAMURA, T. NAKAMURASearch for more papers by this authorA. KIRA, A. KIRASearch for more papers by this authorM. IMAMURA, M. IMAMURASearch for more papers by this author T. NAKAMURA, T. NAKAMURASearch for more papers by this authorA. KIRA, A. KIRASearch for more papers by this authorM. IMAMURA, M. IMAMURASearch for more papers by this author First published: November 23, 1982 https://doi.org/10.1002/chin.198247055AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume13, Issue47November 23, 1982 RelatedInformation

Enhancement of the intersystem crossing of pyrene by metal ions in sodium dodecyl sulfate micelle solutions

Enhancement of the intersystem crossing of pyrene by metal ions in sodium dodecyl sulfate micelle solutions