Experimental investigation and theoretical approach on water soluble acridinderivative as corrosion inhibitor

The effect of 2-methylacridin-9(10H)-one (MAO) on the corrosion of carbon steel in aqueous solution of 1.0 M hydrochloric acid was investigated at different 308K by weight loss, electrochemical techniques and theoretical quantum chemical calculations data indicated that their inhibition effect are closely related to EHOMO, ELUMO, hardness, dipole moment and charge densities. The results obtained showed that MAO could serve as an effective inhibitor for the corrosion of carbon steel in hydrochloric acid media. The results indicated that an increase in the inhibitor concentration leads to an increase in both the charge-transfer resistance (Rct) and inhibition efficiency (IE) and to a decrease of the corrosion current density (Icorr). The inhibitive mechanism was discussed assuming the adsorption of MAO on the electrode surface. Theoretical fitting of different isotherms, Langmuir, Flory-Huggins, and the kinetic-thermodynamic models, were tested to clarify the nature of adsorption.