He Zemin, Yu Ping, Zhang Huimin, Zhao Yuzhen, Zhu Yanfang, Guo Zhun, Ma Cheng, Zhang Haiquan, Miao Zongcheng, Shen Wenbo
Xi'an Key Laboratory of Advanced Photo-electronics Materials and Energy Conversion Device, Key Laboratory of Organic Polymer Photoelectric Materials, School of Sciences, Xijing University, Xi'an, 710123, People's Republic of China.
State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, People's Republic of China.
Nanotechnology. 2021 Dec 3;33(8). doi: 10.1088/1361-6528/ac3a3b.
In this work, two silicon nanostructures were doped into polymer/nematic liquid crystal composites to regulate the electric-optical performance. Commercial SiOnanoparticles and synthesized thiol polyhedral oligomeric silsesquioxane (POSS-SH) were chosen as the dopants to afford the silicon nanostructures. SiOnanoparticles were physically dispersed in the composites and the nanostructure from POSS-SH was implanted into the polymer matrix of the composites via photoinduced thiol-ene crosslinking. Scanning electron microscopy results indicated that the implantation of POSS microstructure into the polymer matrix was conducive to obtaining the uniform porous polymer microstructures in the composites while the introduction of SiOnanoparticles led to the loose and heterogeneous polymer morphologies. The electric-optical performance test results also demonstrated that the electric-optical performance regulation effect of POSS microstructure was more obvious than that of SiOnanoparticles. The driving voltage was reduced by almost 80% if the concentration of POSS-SH in the composite was nearly 8 wt% and the sample could be completely driven by the electric field whose voltage was lower than the safe voltage for continuous contact (24 V). This work could provide a creative approach for the regulation of electric-optical performance for polymer/nematic liquid crystal composites and the fabrication of low voltage-driven PDLC films for smart windows.
在这项工作中，两种硅纳米结构被掺杂到聚合物/向列相液晶复合材料中以调节电光性能。选用商用二氧化硅纳米颗粒和合成的硫醇基多面体低聚倍半硅氧烷（POSS-SH）作为掺杂剂来提供硅纳米结构。二氧化硅纳米颗粒物理分散在复合材料中，而POSS-SH形成的纳米结构通过光诱导硫醇-烯交联被植入到复合材料的聚合物基体中。扫描电子显微镜结果表明，将POSS微结构植入聚合物基体有利于在复合材料中获得均匀的多孔聚合物微结构，而引入二氧化硅纳米颗粒则导致聚合物形态疏松且不均匀。电光性能测试结果还表明，POSS微结构的电光性能调节效果比二氧化硅纳米颗粒更明显。如果复合材料中POSS-SH的浓度接近8 wt%，驱动电压可降低近80%，并且样品可以由低于连续接触安全电压（24 V）的电场完全驱动。这项工作可为调节聚合物/向列相液晶复合材料的电光性能以及制备用于智能窗户的低电压驱动聚合物分散液晶薄膜提供一种创新方法。
