Spontaneous striped pattern formation in thin chiral nematic liquid crystal layers
Spontaneous striped pattern formation in thin chiral nematic liquid crystal layers
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DOI：
10.1016/j.molliq.2018.08.029
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发表时间：
2018-11-01
影响因子：
6
通讯作者：
Zola, R. S.
中科院分区：
文献类型：
--
作者：
Biagio, R. L.;De Souza, R. T.;Zola, R. S.
手性液晶中的周期调制被用于多种光学和光子器件中。制造和控制这种图案的一种显著方法是在随着温度降低而生长的薄润湿层中。在这里，我们研究这个条纹形成过程的实验和Monte Carlo模拟。我们报告的CLCs的样品，目前，润湿过渡后，条纹/边缘形成发生通过成核过程或均匀地在整个细胞。这些图案取决于层的间距与厚度的比率、弹性各向异性和锚定强度。虽然这样的过程是有据可查的CLC下施加的领域，我们在这里表明，类似的纹理转变发生在薄层介导的弱锚定在CLC各向同性界面;它发生的值的间距与厚度比远小于在现场驱动的情况下报告的。蒙特卡罗方法采取行动，在模拟实验观察到的纹理，通过使用成对的加性势模型的CLC。与实验现象的定性比较是可能的，其中条纹的形成和它们的行为都与实验一致。(C)2018爱思唯尔B. V.保留所有权利。
Periodic modulations in chiral nematic liquid crystals (CLCs) are used in several optical and photonic devices. A remarkable way of fabricating and controlling such patterns is in a thin wetting layer that grows as temperature is decreased. Here, we study this stripe formation process experimentally and by means of Monte Carlo simulations. We report on samples of CLCs that present, after the wetting transition, a stripe/fringe formation occurring either through a nucleation process or homogeneously across the cell. These patterns depend on the ratio of the pitch to thickness of the layer, elastic anisotropy, and anchoring strength. Although such process is well documented for CLCs under applied field, we show here that similar textural transitions occur in thin layers mediated by the weak anchoring at the CLC-isotropic interface; it happens for values of pitch to thickness ratio much smaller than the ones reported in field driven situation. The Monte Carlo method takes action in simulating the experimentally observed textures by using a pairwise additive potential model for CLCs. A qualitative comparison with the experimental phenomena is possible to be made in which both the stripes formation and their behavior agree with the experiments. (C) 2018 Elsevier B.V. All rights reserved.