Multicolored near-infrared electrochromic polyimides: Synthesis, electrochemical, and electrochromic properties
详细信息 查看全文
- 作者：Jiwei Cai ; Haijun Niu ; Ping Zhao ; Yan Ji ; Lina Ma ; Cheng Wang ; Xuduo Bai ; Wen Wang
- 关键词：Triphenylamine ; Electrochromism ; Polyimides ; Near-infrared ; Functional dyes ; Coloration efficiency
- 刊名：Dyes and Pigments
- 出版年：December, 2013
- 年：2013
- 卷：99
- 期：3
- 页码：1124-1131
- 全文大小：1225 K
文摘
A novel series of multicolored near-infrared electrochromic aromatic polyimides have been synthesized by a conventional two-step polymerization process. All polymers displayed outstanding thermal stability, i.e. 20聽wt% loss in excess of 593聽掳C in nitrogen and high char yields (higher than 68% at 750聽掳C). In addition, the polymer films showed reversible electrochemical oxidation, high coloration efficiency, low switching time, and anodic green electrochromic behaviors. The Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energy levels of these polymers were determined in the range of聽鈭?.759 to聽鈭?.801 and聽鈭?.758 to聽鈭?.002聽eV (vs the vacuum level) by cyclic voltammetry method consisting with the results of quantum chemical calculation well, respectively. The polymer films revealed excellent stability of electrochromic characteristics for the radical cations generated, changing color from original yellowish to green and blue, with the absorption changing from ultraviolet to near-infrared.