Almeida Maëva, Dudzinski Daniel, Rousseau Bastien, Amiel Catherine, Prévost Sylvain, Cousin Fabrice, Le Coeur Clémence
CNRS, ICMPE, UMR 7182, 2 Rue Henri Dunant, Université Paris Est Creteil, 94320 Thiais, France.
Laboratoire Léon Brillouin, Université Paris-Saclay, CEA-CNRS UMR 12 CEA Saclay, 91191 Gif sur Yvette, France.
Molecules. 2023 Aug 29;28(17):6317. doi: 10.3390/molecules28176317.
This study examines the structures of soft surfactant-based biomaterials which can be tuned by temperature. More precisely, investigated here is the behavior of stearic acid (SA) and 12-hydroxystearic acid (12-HSA) aqueous mixtures as a function of temperature and the 12-HSA/SA molar ratio (R). Whatever R is, the system exhibits a morphological transition at a given threshold temperature, from multilamellar self-assemblies at low temperature to small micelles at high temperature, as shown by a combination of transmittance measurements, Wide Angle X-ray diffraction (WAXS), small angle neutron scattering (SANS), and differential scanning calorimetry (DSC) experiments. The precise determination of the threshold temperature, which ranges between 20 °C and 50 °C depending on R, allows for the construction of the whole phase diagram of the system as a function of R. At high temperature, the micelles that are formed are oblate for pure SA solutions (R = 0) and prolate for pure 12-HSA solutions (R = 1). In the case of mixtures, there is a progressive continuous transition from oblate to prolate shapes when increasing R, with micelles that are almost purely spherical for R = 0.33.
本研究考察了可通过温度调节的基于软表面活性剂的生物材料的结构。更确切地说，这里研究的是硬脂酸（SA）和12-羟基硬脂酸（12-HSA）水混合物随温度以及12-HSA/SA摩尔比（R）的变化行为。无论R为何值，该体系在给定的阈值温度下都会发生形态转变，从低温下的多层自组装结构转变为高温下的小胶束，这通过透射率测量、广角X射线衍射（WAXS）、小角中子散射（SANS）和差示扫描量热法（DSC）实验的组合得以证明。阈值温度的精确测定（其根据R在20℃至50℃之间变化）使得能够构建该体系作为R的函数的完整相图。在高温下，对于纯SA溶液（R = 0）形成的胶束是扁球形的，而对于纯12-HSA溶液（R = 1）形成的胶束是长球形的。在混合物的情况下，当增加R时，存在从扁球形到长球形的逐渐连续转变，对于R = 0.33时胶束几乎是纯球形的。
