Investigation on the inhibition behavior of a pentaerythritol glycoside for carbon steel in 3.5% NaCl saturated Ca(OH)2 solution

A pentaerythritol glycoside (PG) was synthesized and then its corrosion inhibition for carbon steel in 3.5% NaCl saturated Ca(OH)2 solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), as well as atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Results indicated that the PG compound acted as an anodic inhibitor by strong chemical interaction with the carbon steel surface according to the Langmuir adsorption isotherm. The inhibition efficiency and pitting potential on carbon steel increased with increasing concentrations of the inhibitor. Zero charge potential measurements and quantum chemical calculations provided insight into the inhibition mechanism, which are discussed.

AFM three-dimensional images for carbon steel specimens immersed in 3.5% NaCl sat. Ca(OH)2 solution: (a) without the inhibitor, (b) with 0.28 μM inhibitor.Figure optionsDownload as PowerPoint slideHighlights
► The best inhibition efficiency of glycoside is 89.8% under study conditions.
► The compound acts as an anodic inhibitor and obeys the Langmuir adsorption mode.
► The inhibitor can hinder Cl− access to steel surface and retard localized corrosion.
► Inhibition mechanism is explained by experimental and theoretical calculation data.