Direct electropolymerized coatings of polythiophene-CNT on copper and their corrosion protection performance

چکیده مقاله

Copper is widely used in many fields due to its good corrosion resistance as well as its mechanical properties. The resistance to corrosion in aqueous media is attributed to the presence of a thin protective chromium-enriched oxide film. Several strategies have been used to generate more protective interfaces on copper, including the use of conducting polymers [1, 2]. In this work, homogeneous, uniform and adherent polythiophene-carbon nanotube (Pthio-CNT) nanocomposite coatings were electrosynthesized on copper by using the current density fixed in the under galvanostatic conditions method. The synthesized coatings were characterized by Fourier transform infrared spectroscopy (FT-IR), SEM and UV-Vis spectroscopy. The corrosion performances of coatings were investigated in 5000 ppm NaCl solution used by the potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS).The current corrosion decreases significantly from 180 µA cm −2 for blank electrode copper to 0.3 µAcm −2 for Pthio-CNT nanocomposite coatings, under optimal conditions. Also, the potential corrosion increases from -380 mV versus Ag/AgCl for blank electrode copper to -42 mV versus Ag/AgCl for Pthio-CNT nanocomposite coated copper electrodes under optimal conditions. The results of this study clearly ascertain that the Pthio-CNT has outstanding potential to protect the copper against corrosion in a chloride environment.