Isotropic Elastic Stress Induced Large Temperature Range Liquid Crystal Blue Phase at Room Temperature.
Isotropic Elastic Stress Induced Large Temperature Range Liquid Crystal Blue Phase at Room Temperature.
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室温下各向同性弹性应力诱导大温度范围液晶蓝相。
DOI：
10.1021/acs.jpcc.6b05631
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Li,Guoqiang
中科院分区：
文献类型：
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作者：
Manna,SumanK;Dupont,Laurent;Li,Guoqiang
首次在室温下，通过在非介晶各向同性液体的帮助下仅稀释手性-手性混合物，证明了基于常规棒状介晶的手性稳定蓝相（BP）。观察到，添加该各向同性液体不仅使BP在室温下稳定，而且还将BP的温度范围（在加热和冷却期间可逆）显著改善至超过28 °C的水平。除此之外，我们还观察到它的微秒电光响应时间和外电场诱导的波长调谐，这是下一代光学器件，光子显示器，激光器等不可或缺的两个要求。在这里，我们提出，各向同性液体同时起着两个至关重要的作用。一方面，它降低了BP混合物的有效弹性模量（EEM），并在室温下稳定BP，另一方面，它增加了BP的相邻晶胞之间的相互取向有序的对称性。因此，所得到的混合物变得更好地抵抗由于温度变化而引起的一些微观变化，甚至在大范围内。
A thermodynamically stable blue phase (BP) based on the conventional rod like nematogen is demonstrated for the first time at room temperature by only diluting a chiral–nematic mixture with the help of some nonmesogenic isotropic liquid. It is observed that addition of this isotropic liquid does not only stabilize the BPs at room temperature, but also significantly improves the temperature range (reversible during heating and cooling) of the BPs to the level of more than 28 °C. Apart from that, we have observed its microsecond electro-optic response time and, external electric field induced wavelength tuning, which are the two indispensable requirements for next generation optical devices, photonic displays, lasers, and many more. Here we propose that the isotropic liquid plays two crucial roles simultaneously. On one hand, it reduces the effective elastic moduli (EEM) of the BP mixtures and stabilizes the BPs at room temperature, and on the other hand, it increases the symmetry of the mutual orientation ordering among the neighboring unit cells of the BP. Hence, the resultant mixture becomes better resistive to some microscopic change due to the change in temperature, even over a large range.