Effect of water-soluble chitosan on the electrochemical corrosion behaviour of mild steel

Abstract

Abstract This article outlines the role of chitosan as a potent inhibitor on mild steel in 3.65% NaCl. The protective ability of chitosan was evaluated by potentiodynamic polarization (PP) measurements in 36.5% sodium chloride medium. The outcome of the experiment shows that mild steel in sodium chloride solution containing chitosan nanoparticles exhibit better corrosion protection than mild steel in NaCl solution alone because the anodic and cathodic site of the steel were blocked by chitosan nanoparticles, thereby minimising the incursion of the salt solution by forming a thin film on the mild steel surface. The inhibitive efficiency of chitosan nanoparticles was also studied using weight loss. The weight loss by mild steel in NaCl solution was found to be higher than those immersed in NaCl-chitosan nanoparticulate solutions. The loss in weight reduces as the concentration of chitosan nanoparticles increases, indicating the fortifying ability of chitosan nanoparticles. Results obtained show that chitosan could offer inhibition efficiency above 90%. The mixed inhibition characteristic of chitosan was demonstrated by the Tafel curve. The Langmuir isotherm possesses an R2 value of 0.9957 indicating the effectiveness of chitosan as an inhibitor.