Electrolyte effects of poly(3-methylthiophene) via PET/ITO and synthesis of 5-(3,6-di(thiophene-2-yl)-9H-carbazole-9-yl) pentanitrile on electrochemical impedance spectroscopy

Abstract

In this article, 3-methylthiophene (3MTh) and 5-(3,6-di(thiophene-2-yl)-9H-carbazole-9-yl) pentanitrile (ThCzpN) comonomer were electrochemically deposited on poly(ethylene terephthalate)/indium tin oxide (PET/ITO) electrode and carbon fiber micro electrode (CFME) in sodium perchlorate (NaClO4)/acetonitrile (ACN), respectively. ThCzpN comonomer was characterized by 1H-nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy (FTIR) analysis. Poly(ThCzpN)/CFME is characterized by cyclic voltammetry (CV), Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), and electrochemical impedance spectroscopy (EIS). The detailed characterization of the resulting electrocoated poly(3MTh) on PET/ITO thin films was studied by different techniques, i.e., CV and EIS. The effects of electrolytes after electrocoated of modified electrodes were examined by EIS technique in various electrolytes medium (sodium perchlorate (NaClO4), lithium perchlorate (LiClO4), tetraethyl ammonium tetrafluoroborate (TEABF4), and tetrabutyl ammonium tetrafluoroborate (TBABF4)/acetonitrile (ACN) solution). Capacitive behaviors of modified PET/ITO electrode were defined via Nyquist, Bode-magnitude, Bode-Phase, and admittance plots. Variation of capacitance values by various electrolytes and low-frequency capacitance (CLF) values are presented. CLF value electrocoated polymer thin film by CV method in the 0.1M NaClO4 electrolyte with a charge of 7.898 mC was obtained about 59.1 mF cm-2. The highest low-frequency capacitance (CLF) was obtained from the Nyquist plot with [ThCzpN]0 = 3 mM as 0.070 mF cm-2. Equivalent circuit model [R(QR(CR)(RW))(CR)] was suggested for poly(3MTh) on PET/ITO in four different electrolytes medium. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012