Electrochromic Self-Electrostabilized Polypyrrole Films Doped with Surfactant and Azo Dye.

Bayat Bayat,Dinari Dinari,Alemán Alemán,Izadan Izadan,Santiago Santiago,Estrany Estrany,Sánchez Sánchez,Guirado Guirado,Semnani Semnani,Molina Molina

doi:10.3390/polym11111757

Bayat Bayat, Dinari Dinari + Show 8 more

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https://doi.org/10.3390/polym11111757

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Abstract

Two azo dyes, acid red 1 (AR1) and acid red 18 (AR18), were used alone or in combination with sodium dodecyl sulfate (SDS) for the electropolymerization of a pyrrole monomer. Polypyrrole (PPy) showed higher redox capacity when SDS and AR18 were used simultaneously as dopant agents (PPy/AR18-SDS) than when the conducting polymer was produced in the presence of SDS, AR18, AR1, or an AR1/SDS mixture. Moreover, PPy/AR18-SDS is a self-stabilizing material that exhibits increasing electrochemical activity with the number of oxidation–reduction cycles. A mechanism supported by scanning electron microscopy and X-ray diffraction structural observations was proposed to explain the synergy between the SDS surfactant and the AR18 dye. On the other hand, the Bordeaux red color of PPy/AR18-SDS, which exhibits an optical band gap of 1.9 eV, rapidly changed to orange-yellow and blue colors when films were reduced and oxidized, respectively, by applying linear or step potential ramps. Overall, the results indicate that the synergistic utilization of AR18 and SDS as dopant agents in the same polymerization reaction is a very successful and advantageous strategy for the preparation of PPy films with cutting-edge electrochemical and electrochromic properties.

Highlights

In the last few decades, intrinsically conducting polymers (ICPs) emerged as efficient materials for electronic applications, opening up the era of plastic electronics
The electrochemical properties of azo dye-containing PPy films were compared as a function of the chemical structure of the azo dye, the presence or absence of surfactant in the polymerization medium, and the electrochemical procedure used for the anodic polymerization
The highest electrochemical activity and stability were observed in films produced by CP using a reaction medium that, in addition of the Py monomer, contained a surfactant and the azo dye with the largest number of charged sulfonate groups

Summary

Introduction

In the last few decades, intrinsically conducting polymers (ICPs) emerged as efficient materials for electronic applications, opening up the era of plastic electronics. Among heterocyclic ICPs, polypyrrole (PPy) captured the attention of the scientific community since its interesting characteristics (e.g., conductivity, environmental stability, mechanical properties, biocompatibility, and high yield in redox processes) can be tuned with the dopant agent [1,2,3,4,5]. Due to these advantageous properties, PPy was used in many technological and biomedical applications, for example, electrodes for batteries [6,7] and supercapacitors [8,9], bioactive platforms for cell adhesion [10,11] and biosensing [12,13,14], neural interfaces [15,16], and electrochromic devices [17,18,19]. The large conjugated system of dyes can exert electronic interaction with the π-system of the ICP, altering the electronic properties of PPy [24]

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