Photo‐Rewritable Glaring Patterns Composed of Stripe Domains in Nematic Elastomers
Photo‐Rewritable Glaring Patterns Composed of Stripe Domains in Nematic Elastomers
复制标题
向列弹性体中由条纹域组成的光可重写眩光图案
DOI：
10.1002/marc.202200599
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发表时间：
2022
影响因子：
4.6
通讯作者：
Koyama Emiko
中科院分区：
文献类型：
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作者：
Ohzono Takuya;Koyama Emiko
聚合物材料中的动态有序微图案为按需调节光学特性以实现智能光学材料提供了有效方法。在这项研究中，它表明，表现出强烈的各向异性光扩散的眩光模式可以在特定位置开发具有光敏偶氮苯单元的液晶弹性体。眩光源于在没有任何复杂的光刻技术的情况下，在简单的单轴拉伸和释放过程之后在光照射区域中自组织的指向矢的条纹域。由光诱导的顺式偶氮苯异构体瞬时降低的π阶释放熵弹性，这引起局部单轴收缩，导致形成条纹域的指向矢屈曲。由于各向异性光漫射的差异，膜上的写入图案在背光下是有形可见的。此外，该图案可以通过光照射或热退火来擦除。这些薄膜可应用于光学元件，以实现增强照明、安全标签和标牌应用。
Dynamic ordered micropatterns in polymeric materials provide an effective approach for the on‐demand tuning of optical properties toward a smart optical material. In this study, it is shown that glaring patterns exhibiting strong anisotropic light diffusion can be developed at specific locations in nematic liquid‐crystal elastomers with light‐sensitive azobenzene units. Glaring originates from the stripe domains of the nematic directors that self‐organize in light‐irradiated regions after a simple uniaxial stretching and releasing process without any complicated lithographic technique. The nematic order transiently reduced by the photo‐induced cis azobenzene isomers unlocks entropic elasticity, which induces local uniaxial shrinkage that causes buckling of the directors forming stripe domains. The written pattern on the film is tangibly visible with the backlight owing to the difference in anisotropic light diffusion. Furthermore, this pattern can be erased by light irradiation or thermal annealing. These films can be applied to optical elements for achieving augmented luminaries, security labeling, and sign‐sheeting applications.