Electrodeposited Copolymer Films with Tunable Conductivity

Claire Magnenet,Sophie Lakard,Sandrine Monney,Boris Lakard,Emmanuel Contal

doi:10.3390/electrochem1040023

Claire Magnenet, Sophie Lakard + Show 3 more

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https://doi.org/10.3390/electrochem1040023

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Abstract

Conducting copolymer films were prepared from pyrrole (Py) and 1,12-di-(1-pyrrolyl) dodecane (DiPy) in an attempt to prepare conducting films that can be used as sensitive material of chemiresistor gas sensors. Copolymer thin films were obtained by electrochemical oxidation in a lithium perchlorate/acetonitrile electrolyte with different feed ratios of comonomers. Increasing the portion of DiPy in the comonomer mixture resulted in the formation of thinner and less rough copolymer films and to a modification of their morphology from a granular structure to a clover-like structure. In addition, copolymer films with very different conductivities were obtained by varying the comonomers ratio. Indeed, the conductivity of the copolymer containing 91% of Py was 2 × 105 times higher than the conductivity of the polymer containing 91% of DiPy, indicating that it is possible to tune the conductivity of the film by varying the composition of the initial comonomer mixture.

Highlights

The discovery of polyacetylene [1] has generated a great interest for electrically conducting organic polymers such as polypyrroles, polyanilines, or polythiophenes [2,3]
Electrochemical oxidation of DiPy was performed in 0.1 M LiClO4/acetonitrile solution using cyclic voltammetry (CV)
A strong oxidation peak is visible during the anodic oxidation of Py monomers at +1.45 V/Saturated Calomel Electrode (SCE) (Figure 1d), but this peak is still present after each repetitive cycle indicating that the electrodeposition of a conducting polypyrrole film takes place at the Pt electrode

Summary

Introduction

The discovery of polyacetylene [1] has generated a great interest for electrically conducting organic polymers such as polypyrroles, polyanilines, or polythiophenes [2,3]. Polypyrrole films have been used for various applications including: batteries and energy storage [7,8,9], tissue engineering [10], drug delivery [11], cytometry [12,13], and biosensors [5] To overcome these drawbacks, a strategy consists of the copolymerization of pyrrole with other monomers since copolymerization offers the possibility to modify the physico-chemical properties of the prepared films. Waware et al prepared poly(aniline-co-3-nitroaniline) films with varying compositions obtained by in situ oxidative copolymerization of aniline and 3-nitroaniline by altering the molar ratio of monomers [18] These films exhibited electrical conductivity comprised between 1.53 × 10−6 and 3.46 × 10−6 S/cm

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