Passive characteristics and Arrhenius responses of expired inhibitor drug on UNG1050 steel

Abstract

Abstract The study investigated the efficiency of Artemether/Lumefantrine drug for the inhibition of mild steel corrosion in 0.625M NaCl solution using potentiodynamic polarisation. It also attempted to ascertain the inhibition method, the thermodynamic parameters involved and the adsorption mechanism. Surface morphology was also assessed through scanning electron micrography (SEM). The results confirmed that artemether/lumefantrine inhibits the corrosion of mild steel in 0.625M salt solution fairly well with an efficiency of 75% at 298 K with 20ml of inhibitor used. The efficiency reduced when temperature was increased but it increased when inhibitor concentration was raised which suggests that the inhibition efficiency is inversely proportional to temperature but directly proportional to concentration. It was found to operate with mixed inhibition and the Langmuir adsorption isotherm best matches the behaviour of the inhibitor in the experiment with a minimum correlation coefficient of 0.975.