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Article Citation - WoS: 24Citation - Scopus: 25A Novel Conducting Polymer Based on Terthienyl System Bearing Strong Electron-Withdrawing Substituents and Its Electrochromic Device Application(Elsevier Science Sa, 2008) Asil, Demet; Cihaner, Atilla; Algi, Fatih; Onal, Ahmet M.A novel conducting polymer bearing strong electron-withdrawing substituents (EWS) directly attached to the 3,4-positions of the thiophene ring was synthesized by electrochemical polymerization of diethyl 2,5-di(thiophen-2-yl)thiophene-3,4-dicarboxylate (SSS-Diester). The polymer (PSSS-Diester) was characterized by cyclic voltammetry, FT-IR and UV-vis spectroscopy. The polymer has a reversible redox process and demonstrates a stable electrochromic behavior: reddish orange in the neutral state, brown in the intermediate state and green in the oxidized state. Optical density and response time of the dual-type electrochromic device based on PSSS-Diester were found to be 0.23 and 0.6 s at 623 nm, respectively. It is also noteworthy that the device shows good environmental and redox stability (i.e. 94% of the optical activity of the device retained after 500th switch). (c) 2008 Elsevier B.V. All rights reserved.Article Citation - WoS: 25Citation - Scopus: 26Electrochemical Synthesis of Poly(3-Bromo and Its Device Application(Elsevier Science Sa, 2007) Cihaner, Atilla; Onal, Ahmet M.A functionalized thiophene containing both an electron withdrawing and an electron donating group, 3-bromo-4-methoxythiophene (BrMeOTh) was succesfully polymerized in acetonitrile containing 0.1 M tetrabutylammonium tetrafluoroborate (TBABF4) electrolyte via electrochemical oxidation of the corresponding monomer. BrMeOTh exhibits a lower oxidation potential (1.68 V vs Ag/AgCl) than thiophene (2.05 V vs Ag/AgCl). Spectroelectrochemical properties of poly(3-bromo-4-methoxythiophene) (PBrMeOTh) was investigated in situ recording the electronic absorption spectra of the polymer film coated on indium-tin oxide (ITO) at various potentials. The maximum transmittance difference between the oxidized and reduced states was measured as 39.2% and the time required to attain 90% of the total transmittance difference was found to be 1.2 s. Both cyclic voltammetric and spectroelectrochemical studies showed that the polymer exhibit a lower oxidation potential, a relatively narrow band gap, a stable conducting state and a higher degree of electrochemical reversibility. It is also found that, as synthesized PBrMeOTh films possess a linear structure along the polymer backbone. Moreover, dual type electrochromic device of PBrMeOTh with poly(3,4-diethylenedioxythiohene) (PEDOT) was constructed and its spectroelectrochemical, electrochromic switching and open circuit stability were investigated. Dual electrochromic device showed a good optical contrast and distinctive color changes with the ability of good switching times (1.1 s) under atmospheric pressure. (c) 2006 Elsevier B.V. All rights reserved.
