Gemini Cationic Schiff Bases and Their Metal Complexes in Preventing Carbon Steel Dissolution in Acidic Medium

Abstract

The protection of carbon steel in the presence of three cationic Schiff bases and their copper and cobalt complexes in 0.5 M H₂SO₄ was investigated in terms of corrosion inhibition efficiency using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) methods. The results showed high corrosion inhibition efficiency of the inhibitors and their metal complexes. The inhibition efficiency was raised by increasing the inhibitors concentration. From polarization curves, the inhibitors act as mixed type ones. The EIS spectra exhibit a large capacitive loop at high frequencies followed by a large inductive one at low frequencies.