Aqueous Binary Mixtures of Stearic Acid and Its Hydroxylated Counterpart 12-Hydroxystearic Acid: Cascade of Morphological Transitions at Room Temperature

被引:4
|
作者
Almeida, Maëva [1 ,2 ]
Dudzinski, Daniel [2 ]
Amiel, Catherine [1 ]
Guigner, Jean-Michel [3 ,4 ]
Prevost, Sylvain [5 ]
Le Coeur, Clemence [1 ,2 ]
Cousin, Fabrice [1 ]
机构
[1] Univ Paris Est Creteil, Inst Chim & Mat Paris Est, CNRS, UMR 7182, 2 Rue Henri Dunant, F-94320 Thiais, France
[2] Univ Paris Saclay, Lab Leon Brillouin, CEA, CNRS,UMR 12,CEA Saclay, F-91191 Saclay, France
[3] Sorbonne Univ, Inst Mineral Phys Mat & Cosmochim IMPMC, IRD, CNRS,MNHN, CEDEX 05, F-75252 Paris, France
[4] CNRS, UMR 7590, F-75252 Paris 05, France
[5] Inst Laue Langevin, 71 Ave Martyrs,CS 20156, F-38042 Grenoble 9, France
来源
MOLECULES | 2023年 / 28卷 / 11期
关键词
hydroxystearic acid; stearic acid; self-assembly; mixtures; small angle neutron scattering; FATTY-ACIDS; CARBOXYLATE SURFACTANTS; LANGMUIR MONOLAYERS; SELF-ASSEMBLIES; MOLECULAR GELS; PHASE-BEHAVIOR; LIPID TUBES; MOLAR RATIO; HIGH PH; X-RAY;
D O I
10.3390/molecules28114336
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Here, we describe the behavior of mixtures of stearic acid (SA) and its hydroxylated counterpart 12-hydroxystearic acid (12-HSA) in aqueous mixtures at room temperature as a function of the 12-HSA/SA mole ratio R. The morphologies of the self-assembled aggregates are obtained through a multi-structural approach that combines confocal and cryo-TEM microscopies with small-angle neutron scattering (SANS) and wide-angle X-ray scattering (WAXS) measurements, coupled with rheology measurements. Fatty acids are solubilized by an excess of ethanolamine counterions, so that their heads are negatively charged. A clear trend towards partitioning between the two types of fatty acids is observed, presumably driven by the favorable formation of a H-bond network between hydroxyl OH function on the 12th carbon. For all R, the self-assembled structures are locally lamellar, with bilayers composed of crystallized and strongly interdigitated fatty acids. At high R, multilamellar tubes are formed. The doping via a low amount of SA molecules slightly modifies the dimensions of the tubes and decreases the bilayer rigidity. The solutions have a gel-like behavior. At intermediate R, tubes coexist in solution with helical ribbons. At low R, local partitioning also occurs, and the architecture of the self-assemblies associates the two morphologies of the pure fatty acids systems: they are faceted objects with planar domains enriched in SA molecules, capped with curved domains enriched in 12-HSA molecules. The rigidity of the bilayers is strongly increased, as well their storage modulus. The solutions remain, however, viscous fluids in this regime.
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页数:24
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