具有高对比度比的无色到彩色切换电致变色聚酰亚胺。

Colorless-to-colorful switching electrochromic polyimides with very high contrast ratio.

机构信息

Department of Chemical Engineering, National Taiwan University of Science and Technology, 10607, Taipei, Taiwan.

School of Materials Science and Engineering, University of New South Wales, 2052, NSW, Australia.

出版信息

Nat Commun. 2019 Mar 18;10(1):1239. doi: 10.1038/s41467-019-09054-8.

Colorless-to-colorful switching electrochromic polymers with very high contrast ratio are unattainable and attractive for the applications of smart wearable electronics. Here we report a facile strategy in developing colorless-to-colorful switching electrochromic polyimides by incorporating with alicyclic nonlinear, twisted structures and adjusted conjugated electrochromophores, which minimize the charge transfer complex formation. It is noted that, by controlling the conjugation length of electrochromophore, the colorless-to-black switching electrochromic polymer film (PI-1a) exhibites an ultrahigh integrated contrast ratio up to 91.4% from 380 to 780 nm, especially up to 96.8% at 798 nm. In addition, PI-1a film with asymmetric structure also demonstrates fast electrochemical and electrochromic behaviors (a switching and bleaching time of 1.3 s and 1.1 s, respectively) due to the loose chain stacking, which provides more pathways for the penetration of counterion. Moreover, the colorless-to-black EC device based on PI-1a reveals an overall integrated contrast ratio up to 80%.

具有高对比度的无色至彩色转换电致变色聚合物是难以实现的，但对于智能可穿戴电子产品的应用具有吸引力。在这里，我们报告了一种通过引入脂环族非线性、扭曲结构和调整共轭电致变色基团来开发无色至彩色转换电致变色聚酰亚胺的简便策略，该策略最大限度地减少了电荷转移复合物的形成。值得注意的是，通过控制电致变色基团的共轭长度，无色至黑色电致变色聚合物膜（PI-1a）在 380 至 780nm 范围内表现出高达 91.4%的超高集成对比度，特别是在 798nm 处高达 96.8%。此外，由于链堆积松散，具有不对称结构的 PI-1a 薄膜还表现出快速的电化学和电致变色行为（分别为 1.3s 和 1.1s 的开关和漂白时间），这为抗衡离子的渗透提供了更多途径。此外，基于 PI-1a 的无色至黑色 EC 器件显示出高达 80%的整体集成对比度。