Electrically controllable microstructures and dynamic light scattering properties of liquid crystals with negative dielectric anisotropy
Electrically controllable microstructures and dynamic light scattering properties of liquid crystals with negative dielectric anisotropy
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DOI：
10.1039/c5ra02516h
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发表时间：
2015-04
期刊：
影响因子：
3.9
通讯作者：
Huihui Wang;Ling Wang;Hui Xie;Chenyue Li;Guo Shumeng;M. Wang;Cheng Zou;Deng-Ke Yang;Huai Yang
中科院分区：
文献类型：
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作者：
Huihui Wang;Ling Wang;Hui Xie;Chenyue Li;Guo Shumeng;M. Wang;Cheng Zou;Deng-Ke Yang;Huai Yang
本文基于一种具有负介电各向异性的液晶介质制备了具有新型电开关功能的薄膜，并通过原位形成聚合物网络对其微观结构和动态光散射特性进行了详细研究。结果发现，通过适当地施加具有适当强度的电场，可以根据需要方便地控制所制备的膜在400 nm至3000 nm波长范围内的透光率。与紫外（UV）和可见（维斯）区域相比，当施加超过30 V的电压时，近红外（NIR）区域中的光透射率高得多。然而，连续地提高所施加的电压将增加NIR透射率，而在UV和维斯区域中没有明显的变化。此外，我们还探讨了动态光散射性质与聚合物网络的微观结构之间的关系。随着外加电压的增加，动态散射流的速度增加，导致大尺寸孔隙逐渐出现，随后是边界上有许多微孔的超大连通孔隙。相应地，样品的动态光散射随着聚合物网络的微结构的增加而增加。
In this paper thin films which can potentially function as novel electrically switchable shutters were fabricated based on a commercially available liquid crystal media with negative dielectric anisotropy, and their microstructures and dynamic light scattering properties were investigated in detail by the in situ formation of polymer networks. It was found that the light transmittance of the prepared films in the wavelength range from 400 nm to 3000 nm can be expediently controlled on demand by felicitously applying an electric field with an appropriate strength. Compared to the ultraviolet (UV) and visible (Vis) regions, the light transmittance in the near infrared (NIR) region was much higher when a voltage over 30 V was applied. Continually raising the applied voltage would, however, increase the NIR transmittance without noticeable changes in the UV and Vis regions. Furthermore, we have also explored the relationship between the dynamic light scattering properties and the corresponding microstructures of the polymer network. The velocity of the flow of dynamic scattering increased with the increase of the applied voltage, which led to the gradual appearance of large sized pores followed by oversized connected pores with many tiny holes in the boundary. Accordingly, the dynamic light scattering of the samples increased with the increasing microstructures of the polymer network.