Solvent dielectric effect on electrochemical properties of 3,4-propylenedioxythiophene

Keziban Huner,Abdulkadir Sezai Sarac

doi:10.5599/jese.1035

Abstract

The present study is focused on the electrochemical properties of poly(3,4-propylenedioxythiophene) (Poly(ProDOT)), electrocoated on the single carbon-fiber microelectrode (SCFME) in different electrolytic media, with different solvent dielectric constants (35.9, 41.7, 47.5, 53.3, 59.1 and 64.9). The highest deposition charge density of 24.49 mC cm-2 and the highest specific capacitance of 23.17 mF cm-2 were obtained for Poly(ProDOT) synthesized in a medium with the lowest solvent dielectric constant (e = 35.9). Electrochemical impedance spectroscopy (EIS) results of Poly(ProDOT) coated SCFME measured at open circuit potential showed continuously increased impedance magnitudes as ε was increased from 35.9 to 59.1. For all films, almost capacitive impedance responses at lower frequencies at least were obtained. The highest capacitance was observed for the polymer film synthesized in the medium of e = 35.9. The impedance of this film was also measured in different solvent mixtures with different dielectric constants at open circuit potential.

Highlights

Today, electrochromic, optical and thermoelectric properties of conductive polymers used in many fields continue to be investigated [1,2,3,4,5]
Electrochemical properties of electrochemically synthesized conductive polymers can be investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) [9,10,11,12]
0.1 M TBAPF6 was used as the supporting electrolyte, while acetonitrile (MeCN), propylene carbonate (PC), and their mixtures were used as solvents

Summary

Introduction

Electrochromic, optical and thermoelectric properties of conductive polymers used in many fields continue to be investigated [1,2,3,4,5]. Deposition charge density of electrogrowth (50 mV/s, 20 cycles) of ProDOT (left axis), and specific capacitance (right axis) vs dielectric constant of solvent obtained from CV (200 mV/s) of Poly(ProDOT) in monomer-free 0.1 M TBAPF6.

Results

Conclusion