Preparation and thermo-optical characteristics of a smart polymer-stabilized liquid crystal thin film based on smectic A–chiral nematic phase transition
Preparation and thermo-optical characteristics of a smart polymer-stabilized liquid crystal thin film based on smectic A–chiral nematic phase transition
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DOI：
10.1088/0964-1726/23/12/125038
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发表时间：
2014-11
影响因子：
4.1
通讯作者：
Jian Sun-;Huihui Wang;Ling Wang;H. Cao;Hui Xie;Xu-Yi Luo;Jiu-mei Xiao;H. Ding;Zhou Yang;
中科院分区：
文献类型：
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作者：
Jian Sun-;Huihui Wang;Ling Wang;H. Cao;Hui Xie;Xu-Yi Luo;Jiu-mei Xiao;H. Ding;Zhou Yang;
基于smtic -A (SmA) -手性向列相（N*）相变制备了一种具有温度可控透过率的智能聚合物稳定液晶（PSLC）薄膜，并详细研究了PSLC薄膜的组成和制备条件对其热光学（T-O）特性的影响。在SmA相温度范围内，由于液晶分子的焦点圆锥排列，PSLC表现出强烈的不透明状态，而在更高温度下，由于N*相LC分子的平行排列，PSLC表现出透明状态。重要的是，通过改变光聚合单体/LC/手性掺杂剂的组成，可以制备具有不同相变温度和对比度的PSLC薄膜。根据可固化单体的聚合和LC分子的扩散之间的竞争，紫外线（UV）固化环境温度和紫外线照射强度对聚合物网状结构的大小起着关键作用，从而影响薄膜的对比度和切换速度。我们的观察结果有望为制备智能PSLC薄膜铺平道路，用于智能窗口，热探测器和其他信息记录设备领域。
A smart polymer stabilized liquid crystal (PSLC) thin film with temperature-controllable light transmittance was prepared based on a smectic-A (SmA)–chiral nematic (N*) phase transition, and then the effect of the composition and the preparation condition of the PSLC film on its thermo-optical (T-O) characteristics has been investigated in detail. Within the temperature range of the SmA phase, the PSLC shows a strong opaque state due to the focal conic alignment of liquid crystal (LC) molecules, while the film exhibits a transparent state result from the parallel alignment of N* phase LC molecules at a higher temperature. Importantly, the PSLC films with different temperature of phase transition and contrast ratio can be prepared by changing the composition of photo-polymerizable monomer/LC/chiral dopant. According to the competition between the polymerization of the curable monomers and the diffusion of LC molecules, the ultraviolet (UV) curing surrounding temperature and the intensity of UV irradiation play a critical role in tuning the size of the polymer network meshes, which in turn influence the contrast ratio and the switching speed of the film. Our observations are expected to pave the way for preparing smart PSLC thin films for applications in areas of smart windows, thermo-detectors and other information recording devices.