The effect of the shape of the mesogenic group on the structure and phase behavior of 2,3,4-tris(dodecyloxy)benzenesulfonates with alkaline cations
作者:Maxim A. Shcherbina、Artem V. Bakirov、Andrei N. Yakunin、Uwe Beginn、Linglong Yan、Martin Möller、Sergei N. Chvalun
DOI:10.1039/c3sm51821c
日期:——
Synthesis and mesophase structure characterisation are reported for a group of alkali salts of 2,3,4-tris(dodecyloxy)benzenesulfonic acid. As revealed by a combination of polarizing optical microscopy, differential scanning calorimetry and X-ray scattering, variation of the effective mesogen shape due to changes of the cation size leads to systematic transformation of the materials' phase behaviour. Thermotropic mesophases of different types and dimensionalities were observed: 1D (smectic bilayers), 2D (ordered and disordered columnar phases), and 3D (high-temperature micellar mesomorphic phase, low-temperature crystalline one). Cubic packing prevails when the cation size is small and, thus, the effective mesogen shape is close to the conic one. With increasing ion size, the mesogen shape becomes more tapered, and columnar mesophases appear to be more stable.
报告了一组 2,3,4-三(十二烷氧基)苯磺酸碱式盐的合成和介相结构特征。结合偏振光学显微镜、差示扫描量热法和 X 射线散射法可以发现,阳离子大小的变化导致有效介质形状的变化,从而导致材料相行为的系统转变。我们观察到了不同类型和尺寸的热致性介相:一维(胶粘双层)、二维(有序和无序柱状相)和三维(高温胶束介形相、低温结晶相)。当阳离子尺寸较小时,立方填料占主导地位,因此有效介质形状接近圆锥形。随着离子尺寸的增大,介质形状变得更加锥形,柱状介相似乎更加稳定。