Surface alignment of ferroelectric nematic liquid crystals
Surface alignment of ferroelectric nematic liquid crystals
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DOI：
10.1039/d1sm00734c
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发表时间：
2021-08-10
期刊：
影响因子：
3.4
通讯作者：
Lucchetti, Liana
中科院分区：
文献类型：
--
作者：
Caimi, Federico;Nava, Giovanni;Lucchetti, Liana
向列液晶在显示和光学应用中的成功是由于其光学单轴性、流动性、弹性、对电场的响应性以及与固体表面界面处分子取向的可控耦合的结合。极性向列相的发现为基于液晶的应用开辟了新的可能性，但也需要对该相如何与表面耦合进行新的研究。在这里，我们通过测试不同的摩擦和未摩擦衬底来探索铁电向列相的表面排列，这些衬底的耦合强度和锚定取向不同，并发现了铁电向列相特有的各种行为——在向列取向、拓扑缺陷和电场响应方面——这些行为可以被理解为极性对称性破坏的结果。特别是，我们表明，通过使用摩擦聚合物表面，很容易产生具有平面极性优先排列的电池，并且电池静电（例如电极接地）对铁电有序的整体均匀性有显着影响。
The success of nematic liquid crystals in displays and optical applications is due to the combination of their optical uniaxiality, fluidity, elasticity, responsiveness to electric fields and controllable coupling of the molecular orientation at the interface with solid surfaces. The discovery of a polar nematic phase opens new possibilities for liquid crystal-based applications, but also requires a new study of how this phase couples with surfaces. Here we explore the surface alignment of the ferroelectric nematic phase by testing different rubbed and unrubbed substrates that differ in coupling strength and anchoring orientation and find a variety of behaviors - in terms of nematic orientation, topological defects and electric field response - that are specific to the ferroelectric nematic phase and can be understood as a consequence of the polar symmetry breaking. In particular, we show that by using rubbed polymer surfaces it is easy to produce cells with a planar polar preferential alignment and that cell electrostatics (e.g. grounding the electrodes) has a remarkable effect on the overall homogeneity of the ferroelectric ordering.