The effect of water on the microstructure and properties of benzene/[bmim][AOT]/[bmim][BF4] microemulsions

Bai, Ti; Ge, Rile; Gao, Yanan; Chai, Jinling; Slattery, John M.

doi:10.1039/c3cp53441c

Cited by 18 publications

(17 citation statements)

References 59 publications

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“…When the hydration process is complete, the micellar diameter increases for W 0 > 12 due to the swelling of the micelle. A similar behavior was observed by Bai et al 50 65,74−77 In the present work, 1 H NMR measurements in aqueous bmim-AOT RMs in n-heptane were carried out varying the water content ( Figure 2). The chemical shift changes of hydrogen atoms of the water entrapped, HA′ proton associated with the anion AOT and H2 signal for the bmim + cation (Scheme 1) were evaluated.…”

Section: Langmuirsupporting

confidence: 86%

Characterization of Reverse Micelles Formulated with the Ionic-Liquid-like Surfactant Bmim-AOT and Comparison with the Traditional Na-AOT: Dynamic Light Scattering, ¹H NMR Spectroscopy, and Hydrolysis Reaction of Carbonate as a Probe

et al. 2019

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The present study investigated how the presence of butylmethylimidazolium cation (bmim +) alters the interfacial properties of reverse micelles (RMs) created with the ionic liquidlike surfactant 1-butyl-3-methylimidazolium 1,4-bis-2-ethylhexylsulfosuccinate (bmim-AOT), in comparison to sodium 1,4-bis-2ethylhexylsulfosuccinate (Na-AOT) RMs, employing dynamic light scattering (DLS) and 1 H NMR techniques. Moreover, through the hydrolysis reaction of bis(4-nitrophenyl)carbonate inside both RMs as reaction probe, interfacial properties changes were explored in more detail. The kinetic solvent isotope effect was also analyzed. Micellar systems were formed using n-heptane as external nonpolar solvent and water as the polar component. According to the DLS studies, water is encapsulated inside the organized media; however, a different tendency is observed depending on the cationic component of the surfactant. For Na-AOT system, the results suggest that the micellar shapes are probably spherical, while in the case of bmim-AOT, a transition from ellipsoidal to spherical micelles could be occurring when water is added. 1 H NMR data show that water is structured differently when Na + cation is replaced by bmim + ; in bmim-AOT RMs, the interaction of water with the surfactant is weaker and the water hydrogen-bonding network is less disturbed than in Na-AOT RMs. Kinetic studies reveal that the hydrolysis reaction in bmim-AOT RMs was much more favorable in comparison to Na-AOT RMs. In addition, when water content decreases in bmim-AOT RMs, the hydrolysis reaction rate increases and the solvent isotope effect remains constant, while for Na-AOT solutions, both the reaction rate and the solvent isotope effect decrease. Our results indicate that bmim + cation would be located in the surfactant layer in such a way the negative charge density in the interface is less than that in Na-AOT RMs, and the reaction is more favorable. Additionally, as 1 H NMR studies reveal, the interfacial water molecules would be more available in bmim-AOT RMs to participate in the nucleophilic attack. Therefore, the present study evidences how the replacement of Na + counterion by bmim + alters the composition of the interface of AOT RMs.

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Section: Langmuirsupporting

confidence: 86%

Characterization of Reverse Micelles Formulated with the Ionic-Liquid-like Surfactant Bmim-AOT and Comparison with the Traditional Na-AOT: Dynamic Light Scattering, ¹H NMR Spectroscopy, and Hydrolysis Reaction of Carbonate as a Probe

et al. 2019

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“…The IL, [bmim]-BF 4 , was prepared following the procedure reported in the literature 46 and to remove the coloured impurities, the IL was treated with activated charcoal and then it was filtered. Pyrene and sodium deoxycholate (NaDC; purity B98%) were purchased from Sigma Aldrich and used as received.…”

Section: Methodsmentioning

confidence: 99%

Modulation of the aggregation properties of sodium deoxycholate in presence of hydrophilic imidazolium based ionic liquid: water dynamics study to probe the structural alteration of the aggregates

Kundu

Banik

Roy

et al. 2015

Phys. Chem. Chem. Phys.

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In this article, we have investigated the effect of a hydrophilic ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]-BF4), on the aggregation properties of a biological surfactant, sodium deoxycholate (NaDC), in water. In solution, unlike conventional surfactants it shows stepwise aggregation and the effect of the conventional ionic liquid on the aggregation properties is rather interesting. We have observed concentration dependent dual role of the ionic liquid; at their low concentration, the aggregated structure of NaDC reorganizes itself into an elongated rod like structure. However, the aggregated network is disintegrated into small aggregates upon further addition of ionic liquid. TEM (Transmission Electron Microscopy), SEM (Scanning Electron Microscopy) and FLIM (Fluorescence Lifetime Imaging Microscopy) images also confirmed the structural alteration of NaDC upon varying the concentration of the ionic liquid. The proton NMR data indicate that hydrophobic as well as electrostatic interaction is solely responsible for such structural adaptation of NaDC in the presence of an ionic liquid. The host-guest interaction inside the aggregates is monitored using Coumarin-153 (C-153) and the location of C-153 is probed by varying the excitation wavelength from 375 nm to 440 nm and the two binding sites of the aggregates are affected in a different fashion in the presence of ionic liquid. Excitation in the blue region selects the fluorophores which preferably bind to the buried region of the aggregates, whereas 440 nm excitation corresponds to the guest molecules which are exposed to the solvent molecules. The average solvation time of C-153 is increased in the presence of 1.68 wt% [bmim]-BF4 at λexc = 440 nm i.e. the probe molecules relocate themselves to a more restricted region. However, the average solvation time became 2.6 times faster in the presence of 11.2 wt% [bmim]-BF4, which corresponds to a more polar and exposed region. The time resolved anisotropy measurements and polarity determined by pyrene also supported our results in addition to solvation dynamics measurements. In summary, ionic liquids can modulate the host-guest interaction of bile salt aggregates, which can be used as nanocarriers for drug delivery.

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“…In particular, despite of various studies involving POMs containing lanthanides such as europium in the solid state or organic media, practical applications of these materials remain limited in biological media. [26][27][28] Therefore, development of stimuli-responsive POM-based supramolecular materials with enhanced photoluminescence in aqueous solution is highly desirable for a wide range of biological applications such as sensing and controlled drug release. Besides, POM clusters are mainly employed as molecular catalysts or labels in sensing applications.…”

Section: Introductionmentioning

confidence: 99%

Stimuli-Responsive Polyoxometalate/Ionic Liquid Supramolecular Spheres: Fabrication, Characterization, and Biological Applications

Gong

Wang

et al. 2016

Langmuir

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We report fabrication, characterization, and potential applications of polyoxometalate (POM)/ionic liquid (IL) supramolecular spheres in water for the first time. These supramolecular spheres have highly ordered structures and show excellent reversible self-assembly and tunable photoluminescence properties, which can be manipulated by adjusting pH of the aqueous solution. Specifically, the formation of POM/IL supramolecular spheres results in quenching of fluorescence emitted by Eu-POM because hopping of the d1 electron in the POM molecule is blocked by hydrogen bond existing between the oxygen atom of POM and the carboxylic acid group of IL. However, the fluorescence can be completely recovered by gradually increasing pH of the aqueous solution due to the pH-induced deprotonation of the carboxylic acid group of IL, which results in disassembly of the fabricated supramolecular spheres. Applications of these stimuli-responsive photoluminescent POM-based supramolecular materials are demonstrated in biological media. Dual signaling responses of turbidity and fluorescence are observed simultaneously in the detection of urease and heavy metals based on pH-induced disassembly of the supramolecular spheres during the biochemical events in aqueous solution. In addition, guest molecules are encapsulated into the supramolecular spheres, and controlled release of these entrapped molecules is demonstrated in the presence of external stimuli. This study shows potential of stimuli-responsive POM/IL supramolecular materials in biological applications.

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The effect of water on the microstructure and properties of benzene/[bmim][AOT]/[bmim][BF4] microemulsions

Abstract: In the present contribution, results concerning the role of small amounts of water in the 1-butyl-3-

Cited by 18 publications

References 59 publications

Characterization of Reverse Micelles Formulated with the Ionic-Liquid-like Surfactant Bmim-AOT and Comparison with the Traditional Na-AOT: Dynamic Light Scattering, ¹H NMR Spectroscopy, and Hydrolysis Reaction of Carbonate as a Probe

Characterization of Reverse Micelles Formulated with the Ionic-Liquid-like Surfactant Bmim-AOT and Comparison with the Traditional Na-AOT: Dynamic Light Scattering, ¹H NMR Spectroscopy, and Hydrolysis Reaction of Carbonate as a Probe

Modulation of the aggregation properties of sodium deoxycholate in presence of hydrophilic imidazolium based ionic liquid: water dynamics study to probe the structural alteration of the aggregates

Stimuli-Responsive Polyoxometalate/Ionic Liquid Supramolecular Spheres: Fabrication, Characterization, and Biological Applications

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The effect of water on the microstructure and properties of benzene/[bmim][AOT]/[bmim][BF4] microemulsions

Abstract: In the present contribution, results concerning the role of small amounts of water in the 1-butyl-3-

Cited by 18 publications

References 59 publications

Characterization of Reverse Micelles Formulated with the Ionic-Liquid-like Surfactant Bmim-AOT and Comparison with the Traditional Na-AOT: Dynamic Light Scattering, 1H NMR Spectroscopy, and Hydrolysis Reaction of Carbonate as a Probe

Characterization of Reverse Micelles Formulated with the Ionic-Liquid-like Surfactant Bmim-AOT and Comparison with the Traditional Na-AOT: Dynamic Light Scattering, 1H NMR Spectroscopy, and Hydrolysis Reaction of Carbonate as a Probe

Modulation of the aggregation properties of sodium deoxycholate in presence of hydrophilic imidazolium based ionic liquid: water dynamics study to probe the structural alteration of the aggregates

Stimuli-Responsive Polyoxometalate/Ionic Liquid Supramolecular Spheres: Fabrication, Characterization, and Biological Applications

Contact Info

Product

Resources

About

Characterization of Reverse Micelles Formulated with the Ionic-Liquid-like Surfactant Bmim-AOT and Comparison with the Traditional Na-AOT: Dynamic Light Scattering, ¹H NMR Spectroscopy, and Hydrolysis Reaction of Carbonate as a Probe

Characterization of Reverse Micelles Formulated with the Ionic-Liquid-like Surfactant Bmim-AOT and Comparison with the Traditional Na-AOT: Dynamic Light Scattering, ¹H NMR Spectroscopy, and Hydrolysis Reaction of Carbonate as a Probe