Chemically induced splay nematic phase with micron scale periodicity
Chemically induced splay nematic phase with micron scale periodicity
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DOI：
10.1039/c9sm02143d
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发表时间：
2020-01-14
期刊：
影响因子：
3.4
通讯作者：
Mandle, Richard J.
中科院分区：
文献类型：
--
作者：
Connor, Perri L. M.;Mandle, Richard J.
向列型液晶缺乏其组成分子的位置顺序，它们只共享一个平均的取向顺序。调制向列相液晶也缺乏位置顺序，但在平均取向方向上具有周期性变化。在新近发现的斜向列相（N-S）中，平均取向顺序随着垂直于取向的周期性斜向变形而增加。在这篇文章中，我们报道了第一个由两种材料混合而产生的展向列相的例子，这两种材料都没有表现出N-S相。根据其光学结构、x射线散射模式和相关相变的小焓值，确定了斜向列相。我们在光学上测量了展向周期性，发现它与9 μ m相似。这种意想不到的通过二元混合物产生的展向相为材料提供了一条新的途径，可以展示这种相，补充正在进行的结构-性质关系研究，并可以加速利用这种显着的极性向列变体的技术发展。
Nematic liquid crystals lack positional order of their constituent molecules, which share an average orientational order only. Modulated nematic liquid crystal phases also lack positional order, but possess a periodic variation in this direction of average orientation. In the recently discovered splay nematic (N-S) phase the average orientational order is augmented with a periodic splay deformation of orientation perpendicular to the director. In this communication we report the first example of a splay nematic phase which is chemically induced by mixing two materials, neither of which exhibit the N-S phase. The splay-nematic phase is identified based on its optical textures, X-ray scattering patterns, and small enthalpy of the associated phase transition. We measure the splay periodicity optically, finding it to be similar to 9 mu m. This unexpected generation of the splay-nematic phase through binary mixtures offers a new route to materials which exhibit this phase which complements ongoing studies into structure-property relationships and could accelerate the development of technologies utilising this remarkable polar nematic variant.