Synthesis, electropolymerization and oxidation kinetics of an anthraquinone-functionalized poly(3,4-ethylenedioxythiophene)

• Published in: Electrochimica acta 2010-02, Vol.55 (5), p.1535-1542
• Main Authors: Arias-Pardilla, J., Otero, T.F., Blanco, R., Segura, J.L.
• Format: Article
• Language: English
• Subjects: Anthraquinones; Applied sciences; Charge; Electron-conducting polymers; Exact sciences and technology; Functionalized PEDOT; Kinetic coefficient; Monomers; Oxidation; Oxidation kinetics; Photovoltaics; Physicochemistry of polymers; Polymerization; Polymers and radiations; Reaction kinetics; Reduction; Synthesis; Trapped charge
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2009.10.011

The chemical synthesis of an EDOT derivative endowed with an electron acceptor anthraquinone moiety (AQ-EDOT) is described. The electrochemical polymerization of the monomer has been studied by cyclic voltammetry, chronoamperometry and chronopotentiometry. The monomer oxidation-polymerization takes places on platinum at potentials more positive than 1.3 V vs. Ag/AgCl. The polymer film presents a stable redox process with E 0 = 0.22 V, that can be assigned to the characteristic exchange process of the parent unsubstituted PEDOT polymer. An unstable redox process at E 0 = −1.00 V, present decreasing charges on the consecutive cycles despite that the lost reduction charge is recovered by two irreversible oxidation processes taking place at high anodic potentials 0.00 and 0.16 V. A structural charge trapping effects occurring by reduction at −1.1 V and re-oxidation at 0.16 V of the anthraquinone moiety is suggested. The stable redox process is not affected by cycling allowing the obtention of the oxidation empirical kinetics, kinetic coefficients and reaction orders. Different initial states attained by reduction at different cathodic potentials for a constant time were explored for the kinetic study.