Electrochemical Synthesis and Surface Characterization of Poly(3,4-ethylenedioxythiophene) Films Grown in an Ionic Liquid

Abstract

We report a facile method to synthesize poly(3,4-ethylenedioxythiophene) (PEDOT) films at room temperature in a waterproof ionic liquid, 1-ethyl-3-methylimidazolium bis(perfluoroethylsulfonyl)imide (EMIPFSI), by electropolymerization. The ionic liquid leads to the formation of randomly oriented nanofibers and particles confined to submicrometer-sized domains in the film microstructure. X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray (EDX) studies provide information about the intercalation of the cation apart from the reported anion in the polymer film, and on how the imidazolium ion controls the growth of PEDOT nanostructures.

Electrodeposition and Characterisation of Copolymers Based on Pyrrole and 3,4-Ethylenedioxythiophene in BMIM BF4 Using a Microcell Configuration

“…Poly(3,4-ethylenedioxythiophene) (PEDOT) has been extensively used as a conducting polymer as it exhibits outstanding electrochemical stability while cycling, superior air and thermal stability and good electrical properties as a porous structure which ensures a large electrochemical activity and consistent reversible doping-dedoping process, when the film was tested upon repetitive potential cycling in an electrolyte. The deposition of PEDOT [21] in an ionic liquid medium has been described in the literature, in this case 1-ethyl-3-methylimidazolium bis(perfluoroethylsulfonyl)imide (EMIM PFSI). During polymerization in the ionic liquid, both the cation (imidazolium) and the anion (PFSI − ) of the RTIL are included.…”

“…During polymerization in the ionic liquid, both the cation (imidazolium) and the anion (PFSI − ) of the RTIL are included. PEDOT was also successfully deposited using a Ag/AgCl as pseudo-reference electrode (at constant potential of +0.8 V for 5 minutes) on SnO 2 /F coated glass from an extremely hydrophobic ionic liquid without any additional dopant [21]. This difference regarding polymer doping illustrates that the ionic liquid can act as both the growth medium and the dopant to produce the polymer film.…”

Properties and Customization of Sensor Materials for Biomedical Applications

“…While these differences were ascribed primarily to the different viscosities and conductivity of the ILs, effects arising from the cation during the electropolymerization cannot be totally excluded. In certain cases, ILs may affect the structuring of the polymer chains at the nanoscale, as demonstrated by Ahmad et al (146,150), who showed that 1-ethyl-3-methylimidazolium bis(perfluoroethylsulfonyl)imide assisted fiber growth in PEDOT films. These nanostructures tend to shorten diffusion distance for ion transport, which affects the polymer charge/discharge capacities and rates (157) while also increasing electrocatalytic activity (150).…”

“…PEDOT is the most popular CP among the polythiophene family. Compared to PPy, PEDOT has 10 times greater conductivity (300-500 S cm À1 ), greater chemical and thermal stability, and higher optical transparency (144)(145)(146). The green emeraldine salt form of PANi has conductivity in the range 1-10 S cm À1 .…”

“…Of particular interest has been the possibility of improving the mechanical, physical, and chemical properties of CPs by integrating ILs during their electropolymerization (84,87,146,(153)(154)(155). For instance, control of the water content during the electropolymerization seems to affect the conductivity of the CP layers.…”