Evaluation of Fuji Apple Peel Extract as a Corrosion Inhibitor for Carbon Steel in a Saline Medium

摘要

The present study evaluated the activity of extract obtained from the peel of Fuji apples (MalusDomestica) harvested in the region of Valparaiso, Chile, as a potential corrosion inhibitor for carbonsteel in a saline medium. The total phenol and flavonoid content in the extract was measured and itsmain components were identified using HPLC-MS. The inhibition efficiency of the extract wasevaluated by mass loss measurements, Tafel polarisation curves and electrochemical impedancespectroscopy, obtaining an inhibition percentage of around 90% at a concentration of 1000 ppm ofextract. Adsorption of the extract’s components on the surface of the steel followed the Langmuiradsorption isotherm model, implying a physisorption mechanism based on thermodynamic parametersand from the ΔG0ads value, which was calculated at -15.16 KJ/mol. SEM was used to verify thepresence of an organic layer on the steel, corroborating the adsorption of the organic components fromthe extract blocking active sites on the steel.