Electropolymerization and characterization of COOH-functionalized poly(3,4-ethylenedioxythiophene): Ionic exchanges

• Published in: Electrochimica acta Vol. 56; no. 27; pp. 10238 - 10245
• Main Authors: Arias-Pardilla, J., Otero, T.F., Yu, Hsiao-hua
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 30.11.2011; Elsevier
• Subjects: Anion exchanging; Anodic; Cation exchanging; Chemistry; Colour; Electrochemistry; Electrochromic; Electrochromism; Electron-conducting polymers; EQCM; Exact sciences and technology; Exchanging; Functionalized PEDOT; General and physical chemistry; Miscellaneous (electroosmosis, electrophoresis, electrochromism, electrocrystallization, ...); Oxidation; Reduction; UV–Vis; Electron-conducting polymers; Functionalized PEDOT; UV–Vis; Electrochromic; EQCM; UV-Vis; Transition metal; Electrochromism; Electrochemical polymerization; Electrodes; Conducting polymers; Cyclic voltammetry; Absorption spectrometry; Functionalization; Thiophene derivative polymer; Carboxylic acid; Platinum; Acetonitrile; Electrochemical reaction; Spectroelectrochemistry; Quartz microbalance; Ultraviolet visible spectrometry
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2011.09.020

► COOH-functionalized EDOT was successfully electropolymerized by different methods. ► Stored specific charges are higher than those stored in PEDOT. ► Both anion and cation ionic exchange are observed by EQCM experiments. ► UV–Vis spectroelectrochemical results are similar to those obtained from PEDOT. ► After deep p-dedoping some kind of hysteresis is observed during p-doping. The electropolymerization of COOH-functionalized 3,4-ethylenedioxythipohene was investigated by cyclic voltammetry, by anodic potential steps or by flow of a constant anodic current. Compared with PEDOT, an anodic shift of the oxidation polymerization potential is observed. Nevertheless the polymer film oxidation/reduction is shifted to more cathodic potentials, giving higher stored specific charges than those obtained from PEDOT films generated in similar conditions. The generated polymer shows a stable redox process, E0=−0.04V. EQCM results point to a p-doping process exchanging anions with solution, whereas a second reduction process at −0.77V is related to a p-doping process exchanging cations. The new material is electrochromic: it is colourless in its oxidized state and blue colour in its reduced state. UV–Vis spectroelectrochemical results are similar to those obtained from PEDOT films.