The Efficiency of Chloroquine as Corrosion Inhibitor for Aluminium in 1M HCl Solution: Experimental and DFT Study

The effect of chloroquine (4-N-(7-chloroquinolin-4-yl)-1-N,1-N-diethylpentane-1,4- diamine) on the corrosion of aluminium was studied gravimetrically in 1.0 M HCl at 30 and 60 °C. The results showed that chloroquine acted as an excellent corrosion inhibitor for aluminium in acidic medium. The inhibition efficiency increased with increased inhibitor concentration but decreased with the increase in temperature. The kinetic and thermodynamic parameters of chloroquine adsorption were calculated and discussed. The value of the free energy revealed a spontaneous adsorption process. The adsorption of chloroquine on the surface of aluminium obeyed the Freundlich adsorption isotherm at 30 as well as 60 °C. The Koopman’s reactivity descriptors were calculated using the Density Functional Theory at the B3LYP/6-311++G level to elucidate the strength of chloroquine as a corrosion inhibitor.