Mandle Richard J, Cowling Stephen J, Goodby John W
Department of Chemistry, University of York, York, YO10 5DD, UK.
Chemistry. 2017 Oct 17;23(58):14554-14562. doi: 10.1002/chem.201702742. Epub 2017 Sep 18.
Recently, a polar, rod-like liquid-crystalline material was reported to exhibit two distinct nematic mesophases (termed N and N ) separated by a weakly first-order transition. Herein, we present our initial studies into the structure-property relationships that underpin the occurrence of the lower-temperature nematic phase, and report several new materials that exhibit this same transformation. We have prepared material with significantly enhanced temperature ranges, allowing us to perform a detailed study of both the upper- and lower-temperature nematic phases by using small-angle X-ray scattering. We observed a continuous change in d spacing rather than a sharp change at the phase transition, a result consistent with a transition between two nematic phases, structures of which are presumably degenerate.
最近，据报道一种极性棒状液晶材料呈现出两个不同的向列相（称为N相和N相），它们由一个弱一级转变分隔。在此，我们展示了对支撑低温向列相出现的结构-性能关系的初步研究，并报告了几种表现出相同转变的新材料。我们制备了具有显著扩展温度范围的材料，这使我们能够通过小角X射线散射对高温和低温向列相进行详细研究。我们观察到d间距的连续变化，而不是在相变处的急剧变化，这一结果与两个向列相之间的转变一致，其结构可能是简并的。
