Inhibition Action of Maltodextrin on Alkaline Corrosion of Zinc

Abstract: The objective of the work is to introduce and establish the anticorrosion property of maltodextrin (MLD) on the alkaline corrosion of zinc in 0.1 M NaOH. The corrosion and inhibition studies were done by the weight loss method and potentiodynamic polarization (PDP) measurements. Conditions were optimized to get the maximum inhibition efficiency by varying the concentration of the inhibitor in the temperature range of 303–323 K. Activation and thermodynamic parameters were evaluated and discussed in detail. A suitable adsorption isotherm was proposed to fit the experimental results. Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Atomic-force microscopy (AFM), and Attenuated total reflection – Fourier-transform infrared spectroscopy (ATR-FTIR) studies were performed before and after the addition of the inhibitor to analyze the adsorption tendency of MLD onto the metal surface. It was found that the inhibition efficiency of MLD increases with an increase in its concentration and with temperature. The maximum efficiency of 81.1% was achieved for the addition of 0.3 g L^–1 of MLD at 323 K. The obtained results fitted well into the Langmuir adsorption isotherm. Both the surface morphology studies and the spectroscopic investigations confirmed the adsorption of the studied inhibitor onto the metal surface.