A Comprehensive Study on Adsorption and Corrosion Inhibition Efficiency of Acriflavine as an Antibacterial Drug and Inhibitor of Coronaviruses on Mild Steel in 1 M Hcl Solution

A comprehensive study was conducted on the adsorption and corrosion inhibition efficiency of acriflavine (ACF) on mild steel (MS) in 1 M HCl solution. Electrochemical studies were conducted to determine corrosion protection ability of the inhibitor after short and long immersion times. The MS surface after expose to uninhibited and inhibited solutions were characterized by SEM, EDX, AFM and contact angle measurements. The excess surface charge of the metal and some thermodynamic parameters were determined after 1 hour and 6 hours exposure and a possible adsorption and inhibition mechanism was discussed. The electrochemical stability of the surface inhibitor film was studied using potentiodynamic and potentiostatic measurements. It was found that ACF adsorbs on MS surface via dominantly chemical and weakly physical interactions and forms a surface film. The film was adherent, uniform, protective and electrochemically stable. The inhibitor film provides maximum inhibition efficiencies of 92.8% and 97.1% after 1 hour and 6 hours immersion. ACF mitigates the rates of both anodic and cathodic reactions with predominantly second one. The excess surface charge of the steel in the inhibited solution was negative, which becomes more evident after a longer exposure time.