Liquid Crystal Alignment Induced by Polyimides Exposed to Linearly Polarized Light

聚酰亚胺暴露于线偏振光诱导的液晶取向

基本信息

批准号：
10555301
负责人：
IKEDA Tomiki
金额：
$ 7.68万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10555301/
关键词：
Polyimide Alignment Layer Polarized Light Liquid Crystals Photoinduced Alignment Non-Rubbing Alignment 光駆動

项目摘要

Through this study on photoalignment (non-robbing alignment) technique for liquid crystal (LC) devices, we have revealed that aromatic polyimides (Pis) exposed to linearly polarized UV light (366 nm) show a high alignment efficiency without significant change in the chemical structure of PIs. We extended the PI films as an alignment layer to dynamic control technique of nematic LCs (NICs). The most significant characteristic of this system is to utilize photoinduced Freedericksz transition as a trigger to control alignment of NICs. We realized the optical switching of with the photosensitive PIs containing benzophenone moiety as an alignment film. It became clear that the threshold voltage of Freedericksz transition, at which change in the LC alignment occurs, is quite different between irradiated and unitradiated conditions. It was found that photoirradiation at 366 nm resulted in the immediate change in the transmittance when bias voltage of 4.5 V was applied across the cell. Although the mechanism is not well understood at the present stage, formation of intra- or intermolecular charge transfer complexes in the surface area of PI films by photoirradiation ( i.e., change in the polarity) seems to participate in the phenomenon. In conclusion, we have shown for the first time that the photosensitive PI films enable optical control of Freedericksz transition of NLCs. This phenomenon is useful for development of polarization-controllable materials in which permanent electric polarization is controlled by change in dipolar alignment based on Freedericksz transition.

通过这项关于液晶（LC）设备的光19号（非射击比对）技术的研究，我们透露，暴露于线性极化的紫外线光（366 nm）的芳族聚酰亚胺（PIS）显示出很高的对齐效率，而没有PIS化学结构的显着变化。我们将PI膜作为对齐层扩展到列Nematic LCS（NICS）的动态控制技术。该系统最重要的特征是利用光诱导的Freedericksz过渡作为控制NIC的对准的触发。我们以光敏的PI作为对齐膜的光敏性PI实现了光学转换。很明显，在辐射和单位辐射的条件之间，LC对准发生变化的Freedericksz转变的阈值电压是完全不同的。发现在366 nm处的光辐射导致当跨单元施加4.5 V的偏置电压时，透射率立即改变。尽管在当前阶段尚未充分了解该机制，但通过光辐射（即极性变化）在PI膜表面积中形成或分子间电荷转移复合物似乎参与了现象。总之，我们首次表明，光敏的PI膜可以对NLC的Freedericksz过渡进行光学控制。该现象对于开发可控制的材料很有用，在这种材料中，永久性电化受基于Freedericksz过渡的偶极比对的控制控制。