文章信息/Info

Title:

The Research Progress of Cholesteric Liquid Crystals with Broad Reflection band

作者:

王萌; 孫健; 李克軒; 沈文波; 李辰悅; 蘭若塵; 張?zhí)m英; 楊槐

中國礦業(yè)大學(xué)（北京）機電與信息工程學(xué)院

北京大學(xué)工學(xué)院

西京學(xué)院理學(xué)院

Author(s):

WANG Menga;  SUN Jian;  LI Kexuan;  SHEN Wenbo;  LI Chenyued;  LAN ruochen;  ZHANG lanying;  YANG Huai

School of Mechanical Electronic and Information Engineering, China University of Mining and Technology-Beijing

College of Engineering, Peking University

Department of Applied Statistics and Science, Xijing University

School of Materials Science and Engineering, University of Science and Technology Beijing

關(guān)鍵詞:

液晶; 膽甾相; 選擇性反射; 寬波; 螺距非均勻分布

Keywords:

liquid crystals;  cholesteric phase;  selective reflection;  broad bandwidth;  nonuniform pitch distribution

DOI:

10.7502/j.issn.1674-3962.2018.08.06

文獻標(biāo)志碼:

A

摘要:

具有寬波反射特性的膽甾相液晶材料因其特殊的光學(xué)性能及其在反射型顯示器件、光增亮膜、智能節(jié)能玻璃以及激光防護、軍事紅外隱身等各個領(lǐng)域的廣闊應(yīng)用前景而備受關(guān)注。近年來，通過國內(nèi)外眾多科研工作者的努力，多種行之有效的拓寬反射譜帶的方法已被提出。概況而言，需在膽甾相材料體系中構(gòu)筑螺距非均勻分布（包括螺距梯度分布或螺距隨機分布）以實現(xiàn)反射波譜的拓寬。根據(jù)其拓寬機理可分為層疊法、光誘導(dǎo)分子擴散法、熱擴散法、外場刺激手性材料濃度變化或螺旋扭曲力變化法、膽甾相與扭曲晶界相兩相共存法。通過對各個材料體系的研究，膽甾相的反射波寬得到了顯著的拓寬，為膽甾相液晶材料的實際應(yīng)用奠定了基礎(chǔ)。而開發(fā)新材料體系、進一步優(yōu)化器件性能和制備工藝是今后研究發(fā)展的重要方向。

Abstract:

Cholesteric liquid crystal (ChLC) materials with broad reflection band are witnessing a significant surge in interest due to their unique optical properties and potential applications in areas such as reflective polarizer�瞗ree displays, light enhancement films, smart switchable windows, laser protection or IR�瞫tealth. In the decades, extensive investigations have been made on broadening the reflection bandwidth. And several effective methods and processing techniques have been developed. In summary, a variation of pitch (whether a pitch gradient or a random distribution in the volume of materials) is integral to obtain a ChLC with a broad reflection band. According to the broadening mechanisms, they are classified to be stacking method, light induced molecular diffusion method, thermal diffusion method, method of external stimuli�瞚nduced variation in concentration or helical twisting power of chiral compounds, and fabrication of a architecture that combined Ch and twist grain boundary phase nanostructures. Based on these studies, the reflection bandwidth of ChLC has been greatly broadened in each material system, which makes it possible to practical applications. And there are still much works to be done in the future in making innovations in ChLC materials with excellent optical performance, improving performances of functional devices and developing preparation technologies or procedures for industrial production.