Polypyrrole Films for Ion Exchange Membranes: Effect of Surface Treatment and Electropolymerization Medium

ABSTRACT

In this study, conductive PPy films were electropolymerized at 0.8 V versus Ag/AgCl on stainless steel mesh (SSM), with and without chemical pretreatment, using three electrolyte media (organic, aqueous, and acidic) and electropolymerization times of 1800 and 3600 s. The resulting films were characterized by chronoamperometry, electrochemical impedance spectroscopy (EIS), scanning electron microscopy coupled with energy‐dispersive X‐ray spectroscopy (SEM–EDS), and Fourier‐transform infrared (FTIR) spectroscopy. Additionally, the best‐performing films were selected for electrodialysis evaluation. Chemical pretreatment enhanced PPy deposition only in the acidic medium, yielding deposited masses of 54.51 and 97.34 mg at 1800 and 3600 s, respectively, while decreasing deposition in the aqueous and organic media. Films obtained in the acidic medium exhibited the lowest area‐specific interfacial polarization resistance (), more uniform PPy coverage, and more intense FTIR bands. Among these films, CT‐3600‐A exhibited the most favorable electrochemical response and morphological characteristics. In electrodialysis, this film achieved an ionic flux of 86.60 mg m ⁻²  s ⁻¹ and a separation efficiency of 6.17%, corresponding to 91.47% and 91.41%, respectively, of the values obtained with the commercial FAS‐30 membrane. Overall, these findings demonstrate favorable electrochemical, morphological, and functional performance, supporting the potential application of this PPy film as an anion‐exchange membrane (AEM).