Conversion of steel by polyphenolic model molecules: Corrosion inhibition mechanism by rutin, esculin, esculetol. (15th May 2018)

• Record Type: Journal Article
• Authors: Veys-Renaux, Delphine; Reguer, Solenn; Bellot-Gurlet, Ludovic; Mirambet, François; Rocca, Emmanuel
• Is Part Of: Corrosion science. Volume 136(2018)
• Page Start: 1
• Page End: 8
• Publication Date: 2018-05-15
• Subjects: Steel -- Passive films -- Polarization -- AFS (EXAFS and XANES) -- Raman spectroscopy; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2018.02.015
• Languages: English
• ISSNs: 0010-938X

Abstract

Graphical abstract: Highlights: Radical scavenging properties of antioxidant molecules induce cathodic inhibition. Free-catechol molecules form an octahedral tri-catecholate complex with iron (III). The growth of a conversion film of catecholate complex provides an anodic inhibition. Glycosylated catechol molecules are rather adsorbed on oxidized iron film. Abstract: This paper focuses on the potential corrosion protection of steel in presence of three polyphenolic model molecules (rutin, esculin, esculetol) in a weak acidic medium (pH = 4). From an electrochemical point of view, the cathodic inhibition was attributed to the oxygen scavenger role of the considered antioxidant compounds. SEM observations, Raman spectroscopy and Synchrotron X-ray absorption spectroscopy revealed furthermore the formation of a surface film by precipitation of iron polyphenolate conversion products, in which iron III is likely coordinated with free-catechol groups. Glycosylated catechol groups are rather adsorbed on a FeOOH layer.