Micellar growth: Role of molecular geometry and intermolecular hydrogen bonding

Pei, Xiaomei; Zhao, Jianxi; Li, Erjun

doi:10.1016/j.colsurfa.2012.12.017

Cited by 10 publications

(7 citation statements)

References 33 publications

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“…The molecular structures of the surfactants are shown in Scheme . C 12 C 4 (OH) 2 C 12 Br 2 has a four-carbon length spacer and two hydroxyl substitutions and self-assembles into wormlike micelles at high concentration in aqueous solution . Previous reports − have indicated gemini surfactants with hydroxyl groups in spacer greatly promote their micellization in aqueous solution and exhibit strong aggregation capability because of the intermolecular hydrogen binding between the −OH groups, while C 12 Glu can only self-assemble into spherical micelles over a wide range of concentration .…”

Section: Introductionmentioning

confidence: 99%

Temperature-Induced Aggregate Transitions in Mixtures of Cationic Ammonium Gemini Surfactant with Anionic Glutamic Acid Surfactant in Aqueous Solution

Tian

Wang

2016

Langmuir

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The aggregation behaviors of the mixtures of cationic gemini surfactant 1,4-bis(dodecyl-N,N-dimethylammonium bromide)-2,3-butanediol (C12C4(OH)2C12Br2) and anionic amino acid surfactant N-dodecanoylglutamic acid (C12Glu) in aqueous solution of pH = 10.0 have been studied. The mixture forms spherical micelles, vesicles, and wormlike micelles at 25 °C by changing mixing ratios and/or total surfactant concentration. Then these aggregates undergo a series of transitions upon increasing the temperature. Smaller spherical micelles transfer into larger vesicles, vesicles transfer into solid spherical aggregates and then into larger irregular aggregates, and entangled wormlike micelles transfer into branched wormlike micelles. Moreover, the larger irregular aggregates and branched micelles finally lead to precipitation and clouding phenomenon, respectively. All these transitions are thermally reversible, and the transition temperatures can be tuned by varying the mixing ratios and/or total concentration. These temperature-dependent aggregate transitions can be elucidated on the basis of the temperature-induced variations in the dehydration, electrostatic interaction, and hydrogen bonds of the headgroup area and in the hydrophobic interaction between the hydrocarbon chains. The results suggest that the surfactants carrying multiple binding sites will greatly improve the regulation ability and temperature sensitivity.

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Section: Introductionmentioning

confidence: 99%

Temperature-Induced Aggregate Transitions in Mixtures of Cationic Ammonium Gemini Surfactant with Anionic Glutamic Acid Surfactant in Aqueous Solution

Tian

Wang

2016

Langmuir

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“…Further increasing the concentration, the hydrogen bonds occurring less than 5 Å could be strongly enhanced when more hydroxyl groups stay close to each other in the aggregates due to the stronger hydrophobic interaction, contributing to the excessive free energy to the end caps and inducing the formation of long micelles with a lower surface curvature. 56 The role of the hydroxyl groups has been verified in previous work, 48 in which 12-4-12 only forms spherical micelles, whereas hydroxylsubstituted 12-4(OH)-12 and 12-4(OH) 2 -12 can form long micelle.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“… , The two chiral centers are located at the spacer, and hydroxyls are introduced to form intra- or intermolecular hydrogen bonds. Cationic gemini surfactant (±)-12-4(OH) 2 -12 with two hydroxyl groups at the spacer has been reported before. − It presents lower CMC, higher interfacial elasticity, tighter molecular packing in the monolayer, and more abundant aggregate structures compared with the corresponding cationic gemini surfactants with one hydroxyl group at the spacer or without any hydroxyl group. However, its enantiomers and mesomer have not been reported because of the difficulty of synthesis and purification.…”

Section: Introductionmentioning

confidence: 87%

Self-Assembly and Chiral Recognition of Chiral Cationic Gemini Surfactants

Zhou

Yue²,

Fan³

et al. 2018

Langmuir

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Chiral cationic gemini surfactants 1,4-bis(dodecyl-N,Ndimethylammonium bromide)-2,3-butanediol (12-4(OH) 2 -12) including racemate, mesomer, and two enantiomers were synthesized and their selfassembly in aqueous solution has been comparatively investigated by tensiometry, conductometry, 1 H NMR, small-angle neutron scattering, cryogenic transmission electron microscopy, and cryogenic scanning electron microscopy. The chirality at spacer induces different self-assembly behaviors due to the hydrogen-bonding interaction between the hydroxyl groups at the chiral centers. The stereochemistry of the spacer has little effect on the release of the counterions from the surfactant headgroups and on the molecular packing at the air−water interface. The critical micelle concentration (CMC) decreases in the order of racemate > enantiomer > mesomer. Above the CMC, the aggregates of enantiomers transit from small spherical micelles to rodlike and wormlike micelles with increasing concentration, whereas the mesomer and racemate aggregates transform from spherical micelles to rodlike micelles and platelet-like aggregates. The differences may be because the mesomer and racemate molecules mainly form intermolecular hydrogen bonds between the −OH groups, but the enantiomer molecules dominantly form intramolecular hydrogen bonds. Furthermore, it was found that the chiral micelles formed by the enantiomers exhibit enantioselection ability for bilirubin (BR) enantiomers. The recognition capability can be adjusted by the micellar structure, i.e., the rodlike micelles are better than either small spherical micelles or wormlike micelles, which might possess different chiral cavities, controlling BR shape and location. These results demonstrate that the aggregates of chiral gemini surfactants can be used to mimic the chiral recognition in biological membrane.

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“…Besides surfactant geometry, the role of hydrotrope is also vital to form WLMs. For salt-free gemini systems, the solution containing 350 mM gemini 12-4(OH) 2 -12 reaches an approximate solution viscosity of 7 Pa s [39]. The comparable viscosity is measured at 110 mM for a 12-3(OH)-12 aqueous solution without the help of salt [23].…”

Section: Comparison Of Rheological Parametersmentioning

confidence: 91%

Rheological Investigation of Wormlike Micelles Based on Gemini Surfactant in EG–Water Solution

Wei

Han

Zhou

et al. 2016

J Surfact & Detergents

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The self‐assembly behavior of gemini surfactants in ethylene glycol (EG)‐water (5/95, v/v) mixed solvent was investigated by rheological measurements at 10 °C. The influence of molecular structure of the gemini surfactant and added hydrotrope on the solution properties was studied. Sodium salicylate (NaSal) showed stronger ability to induce 2‐hydroxyl‐propanediyl‐α,ω‐bis‐(dimethyldodecylammonium bromide), referred to as 12‐3(OH)‐12, to form wormlike micelles than sodium benzoate. Less NaSal is required to promote a sphere to rod transition and to reach the peak viscosity. Moreover, the concentrations of hydrotrope and gemini surfactant are both lower than conventional single‐chain surfactant systems to reach a comparable viscosity. The strong hydrophobicity of gemini surfactants and hydrotropes is responsible for the high efficiency in forming wormlike micelles in EG/water systems. The geometric structure of gemini surfactants also plays a vital role in self‐assembly into wormlike micelles. Dimethylene‐1,2‐bis‐(dodecyl dimethylammonium bromide), referred to as 12‐2‐12, shows absolute superiority over 12‐3(OH)‐12 in constructing wormlike micelles. The present study will be helpful for developing de‐icing fluids and anti‐freezing solutions, which need rheology control in EG‐aqueous medium at low temperature.

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Micellar growth: Role of molecular geometry and intermolecular hydrogen bonding

Cited by 10 publications

References 33 publications

Temperature-Induced Aggregate Transitions in Mixtures of Cationic Ammonium Gemini Surfactant with Anionic Glutamic Acid Surfactant in Aqueous Solution

Temperature-Induced Aggregate Transitions in Mixtures of Cationic Ammonium Gemini Surfactant with Anionic Glutamic Acid Surfactant in Aqueous Solution

Self-Assembly and Chiral Recognition of Chiral Cationic Gemini Surfactants

Rheological Investigation of Wormlike Micelles Based on Gemini Surfactant in EG–Water Solution

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