Abstract.

Some ionic surfactant-based lyotropic mixtures, exhibiting cholesteric phases, were prepared to investigate the effect of the surfactant alkyl chain length on a) uniaxial-to-biaxial phase transitions and b) stabilization of different cholesteric phases. Potassium alkanoates, KCx, (potassium undecanoate, KC11, potassium dodecanoate, KC12, and potassium tridecanoate, KC13) were chosen as the surfactant molecules. The lyotropic mixtures, which were composed of KCx/potassium sulfate (K₂SO₄)/decanol (DeOH)/water/brucine, where brucine is a chiral dopant molecule, were studied. Partial phase diagrams were constructed to show how the surfactant alkyl chain affects the phase topologies in the phase diagrams. It was observed that the presence of a longer surfactant alkyl chain in the mixture favors the stabilization of the larger discotic cholesteric, Ch_D, and cholesteric biaxial, Ch_B, phase domains. The phase transitions from the uniaxial cholesteric to biaxial cholesteric phase were shifted to lower temperatures.

Graphical abstract

中文翻译：

---

表面活性剂烷基链长对溶致单轴至双轴胆甾相转变的影响。

摘要。

制备了一些显示胆甾相的基于离子表面活性剂的溶致混合物，以研究表面活性剂烷基链长对a）单轴至双轴相变和b）不同胆甾相稳定的影响。选择链烷酸钾KCx（十一烷酸钾KC11，十二烷酸钾KC12和十三烷酸钾KC13）作为表面活性剂分子。由KCx /硫酸钾（K ₂ SO ₄）/癸醇（DeOH）/水/亮氨酸，其中brucine是手性掺杂分子。构建部分相图以显示表面活性剂烷基链如何影响相图中的相拓扑。观察到混合物中存在较长的表面活性剂烷基链有利于较大的盘状胆甾型Ch _D和胆甾型双轴Ch _B的相域的稳定。从单轴胆甾相到双轴胆甾相的相变被转移到较低的温度。

图形概要