Liao G, Shashikala I, Yelamaggad C V, Rao D S Shankar, Prasad S Krishna, Jákli A J
Chemical Physics Interdisciplinary Program and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 May;73(5 Pt 1):051701. doi: 10.1103/PhysRevE.73.051701. Epub 2006 May 1.
We have studied the phase sequence and physical properties of an asymmetric bent-core material with a chiral rigid cholesteryl moiety, and a flexible achiral alkyl side chain at the other end. The combination of the achiral bent core with the chiral cholesteryl unit results in properties different from those of both the usual calamitic and bent-core materials. We find that the presence of the bent core unit induces a wide-temperature-range optically isotropic (probably BPIII) mesophase between the isotropic and cholesteric (chiral nematic) phases. Below the cholesteric phase a ferroelectric smectic-C* structure occurs in which the bent-core units do not seem to form a polar close packing.
我们研究了一种不对称弯曲核材料的相序列和物理性质，该材料一端带有手性刚性胆甾醇部分，另一端带有柔性非手性烷基侧链。非手性弯曲核与手性胆甾醇单元的结合导致了与普通棒状和弯曲核材料不同的性质。我们发现，弯曲核单元的存在会在各向同性相和胆甾相（手性向列相）之间诱导出一个宽温度范围的光学各向同性（可能是BPIII）中间相。在胆甾相以下会出现铁电近晶C*结构，其中弯曲核单元似乎不会形成极性密堆积。
