The design and investigation of the self-assembly of dimers with two nematic phases
The design and investigation of the self-assembly of dimers with two nematic phases
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DOI：
10.1039/c5ra18118f
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发表时间：
2015-01-01
期刊：
影响因子：
3.9
通讯作者：
Mehl, G. H.
中科院分区：
文献类型：
--
作者：
Ahmed, Z.;Welch, C.;Mehl, G. H.
合成了一系列非对称二聚体，其一侧含有氰基联苯或二氟三联苯部分，另一侧含有一系列长、短、弯曲、极性或非极性介晶。介电各向异性的介电基元的变化系统。通过差示扫描量热法（DSC）、光学偏光显微镜（OPM）和详细的X射线衍射（XRD）研究，对该体系的结构进行了表征。结果进行了比较，并讨论了结构与性能的关系。讨论了N-tb结构、共轴螺旋、瑞士卷结构和手性畴的形成，建立了N-x相组装模型。
A series of non-symmetric dimers were synthesised containing either cyanobiphenyl or difluoroterphenyl moieties on one side and a range of long, short, bent, polar or apolar mesogens on the other side of the molecules. The dielectric anisotropy of the mesogens was varied systematically. The systems were characterised by differential scanning calorimetry (DSC), optical polarizing microscopy (OPM) and detailed X-ray diffraction (XRD) studies, both in the nematic and the N-x phase. The results are compared and structure-property relationships are discussed. A model for the assembly in the N-x phase is developed discussing N-tb structures, coaxial helices, swiss roll structures and chiral domain formation.