Influence of Electrodeposition Method, Solvent and Nanoparticle Concentration on Polypyrrole Coatings for Corrosion Protection of Mild Steel

In this work, it was demonstrated that the anti-corrosion performance of the polypyrrole (PPy) coatings on mild steel can be affected by electrodeposition method, electrosynthesis solvent composition and ZnO nanoparticles concentration. Three different electrodeposition methods, namely, cyclic voltammetry, galvanostatic and potentiostatic techniques were empolyed. The anti-corrosion performance of the PPy coatings was investigated by electrochemical impedance spectroscopy. The PPy prepared by potentiostatic method exhibited the best performance against corrosion of mild steel in 3.5% NaCl solution. Then, different mixtures of H2O/ethanol were investigated as electrosynthesis solvents for the preparation of PPy coatings on mild steel via optimized electrodeposition mode (i.e. potentiostatic). Evaluation of the prepared coatings introduced the pure water as the optimum solvent for the PPy electrodeposition. Lastly, the investigation of different concentrations of ZnO nanoparticles proved that the PPy coating containing 0.025% ZnO nanoparticles was the best coating against the corrosion of mild steel in the NaCl solution.