The Synergistic Effects of Halide Ions and Cations on the Corrosion Inhibition of Mild Steel in H2SO4 Using Amodiaquine

Abstract

The synergistic effect of amodiaquine (AMQ) and some selected metal cations (Na + , Mg 2+ ) and halides (Cl -, Br -, I -) on the corrosion of mild steel in 0.5 M H 2 SO 4 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 Iion. The synergistic action was also noted when 10 -2 M Na + , Mg 2+ 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 H 2 SO 4 . Potentiodynamic polarization and electrochemical impedance spectroscopy for mild steel in the synergistic addition of halide and cations confirmed the mixed mode of inhibition.

Nitrogen-containing six-membered heterocyclic compounds as corrosion inhibitors for metals in solutions of mineral acids – A review

“…The studies on quinoline derivatives as CIs of metals in H 2 SO 4 have not been systematized and are fragmentary. The substituted quinoline with the structure poorly inhibits the corrosion of mild steel in 0.5 М H 2 SO 4 even at C in = 0.01 М (Z = 79.4%) [108]. Good protection of steel in H 2 SO 4 can be reached using CIs such as substituted quinolinium iodides or bromides [109], which is a result of synergistic action of the cationic surfactant and halide ions, as well as sulfur-containing quinoline derivatives [102].…”

“…We already discussed above the possibility of improving the protective effect of substituted pyrimidines in corrosion of carbon steel in HNO 3 solutions by KI addition [52]. The synergism of action of the components of a mixture containing a substituted quinoline and halide ions on the corrosion of mild steel in 0.5 M H 2 SO 4 is noted [108].…”