Abstract

The synergistic effect of amodiaquine (AMQ) and some selected metal cations (Na⁺, Mg²⁺) and halides (Cl^-, Br^-, I^-) on the corrosion of mild steel in 0.5 M H₂SO₄ was studied by weight loss methods, electrochemical impedance spectroscopy and potentiodynamic polarization measurements. Efforts were taken to enhance the inhibition efficiency at different concentration of amodiaquine with fixed concentration of cations and halides. As the concentration of amodiaquine increased the inhibition efficiency (IE) increases. Addition of fixed concentration of halides on different concentration of amodiaquine inferred the increase in inhibition efficiency with concentration of amodiaquine. Maximum inhibition efficiency was observed with 10^-2 M amodiaquine and 10^-2 M I^- ion. The synergistic action was also noted when 10^-2 M Na⁺, Mg²⁺ with 10^-4 M amodiaquine. Synergistic parameter for amodiaquine with cations and halides confirmed the synergistic effect of halides and cations and corrosion of mild steel in the presence of 0.5 M H₂SO₄. Potentiodynamic polarization and electrochemical impedance spectroscopy for mild steel in the synergistic addition of halide and cations confirmed the mixed mode of inhibition.

Keywords

Synergistic effect, Corrosion inhibition, Mild steel, Amodiaquine, Halides, Cations