| Reference | [1]. Langmuir. 2010 Feb 2;26(3):1716-23. doi: 10.1021/la9026706.
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Stepwise aggregation of dimethyl-di-n-octylammonium chloride in aqueous
solutions: from dimers to vesicles.
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Leclercq L(1), Nardello-Rataj V, Turmine M, Azaroual N, Aubry JM.
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Author information:
(1)Université Lille 1, LCOM, Equipe Oxydation et Physico-Chimie de la
Formulation, CNRS UMR 8009, F-59655 Villeneuve d’Ascq Cedex, France.
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The self-aggregation of dimethyl-di-n-octylammonium chloride, in diluted aqueous
solutions, was studied with various experimental and theoretical techniques:
zetametry, conductimetry, dimethyl-di-n-octylammonium and chloride-selective
electrodes, tensiometry, NMR spectroscopy ((1)H and DOSY), and molecular
modeling (PM3 and molecular dynamic). The combination of the data obtained by
these techniques led us to propose a stepwise aggregation process with
increasing concentration: dimers (0.2-10 mM), bilayers (10-30 mM), and finally
vesicles (>30 mM).
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DOI: 10.1021/la9026706
PMID: 19791781
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[2]. Langmuir. 2017 Apr 11;33(14):3395-3403. doi: 10.1021/acs.langmuir.6b04073. Epub
2017 Jan 25.
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Supramolecular “Big Bang” in a Single-Ionic Surfactant/Water System Driven by
Electrostatic Repulsion: From Vesicles to Micelles.
<br>
Leclercq L(1), Bauduin P(2), Nardello-Rataj V(1).
<br>
Author information:
(1)Univ. Lille , UMR 8181-UCCS-Unité de Catalyse et Chimie du Solide, F-59000
Lille, France.
(2)Institut de Chimie Séparative de Marcoule, UMR 5257, CEA/CNRS/UM2/ENSCM , BP
17171 CEA Marcoule, F-30207 Bagnols-sur-Cèze, France.
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In aqueous solution, dimethyldi-n-octylammonium chloride, [DiC8][Cl],
spontaneously forms dimers at low concentrations (1-10 mM) to decrease the
strength of the hydrophobic-water contact. Dimers represent ideal building
blocks for the abrupt edification of vesicles at 10 mM. These vesicles are fully
characterized by dynamic and static light scattering, self-diffusion nuclear
magnetic resonance, and freeze-fracture transmission electron microscopy. An
increase in concentration leads to electrostatic repulsion between vesicles that
explode into small micelles at 30 mM. These transitions are detected by means of
surface tension, conductivity, and solubility of hydrophobic solutes as well as
by isothermal titration microcalorimetry. These unusual supramolecular
transitions emerge from the surfactant chemical structure that combines two
contradictory features: (i) the double-chain structure tending to form low
planar aggregates with low water solubility and (ii) the relatively short chains
giving high hydrophilicity. The well-balanced hydrophilic-hydrophobic character
of [DiC8][Cl] is then believed to be at the origin of the unusual supramolecular
sequence offering new opportunities for drug delivery systems.
<br>
DOI: 10.1021/acs.langmuir.6b04073
PMID: 28068101
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