A Conjugated Copolymer Bearing Imidazolium-based Ionic Liquid:Electrochemical Synthesis and Electrochromic Properties

• 作者: Xiao-Jing Lv Li-Bin Xu Liang Qian Yuan-Yuan Yang Zhi-Yi Xu Jin Li Cheng Zhang
• 来源期刊: 高分子科学（英文版）
• 年，卷（期）: 2021,（5）
• 所属期刊栏目: ARTICLES
• 页码范围: 537-544
• 页数: 8页
• 语种: 英文

摘要

An imidazolium-based ionic liquid (IL) modified triphenylamine derivative,namely 1-(4-((4-(diphenylamino)benzoyl) oxy)butyl)-3-methyl imidazole tetrafluoroborate (TPAC6IL-BF4),was designed and synthesized,and further applied with 3,4-ethylene dioxythiophene (EDOT)to prepare conjugated copolymer P(EDOT:TPAC6IL-BF4) via electrochemical polymerization.The cyclic voltammetry curves show that the copolymer P(EDOT:TPAC6IL-BF4) possesses two pairs of redox peaks,which should be ascribed to the redox behaviors of EDOT and triphenylamine.The ultraviolet-visible (UV-Vis) absorption spectrum of P(EDOT:TPAC6IL-BF4) exhibits one maximum absorption peak at 580 nm and a small shoulder characteristic peak at 385 nm under neutral state which are assigned to n-n* conjugated structure of EDOT and triphenylamine.After being applied at the positive voltage,the copolymer color changes from dark blue to light blue,which is close to the color of poly(3,4-ethylenedioxythiophene) (PEDOT).Surprisingly,the copolymer P(EDOT:TPAC6IL-BF4) shows shorter switching time of 0.37 s,0.30 s at 580 nm and 0.38 s,0.45 s at 1100 nm compared with PEDOT.It is more intriguing that the copolymer P(EDOT:TPAC6IL-BF4) exhibits electrochromism even in free supporting electrolyte.The results confirm that the existence of imidazolium-based ionic liquid has an improvement on the ion diffusion properties and the switching time of conjugated polymer,which may provide a potential direction for the preparation of high-performance electrochromic materials.