Experimental and computational studies on heterocyclic organic compounds as corrosion inhibitors for copper immersed in O/W emulsion medium

Abstract

Purpose

Corrosion inhibitors for copper immersed in emulsion were investigated by experiments and theoretical calculations, and this study aims to propose a new inhibition mechanism of the inhibitors having protective effects for copper corrosion.

Design/methodology/approach

Adsorption behavior of penta-heterocycles (thiophene, 1,2,5-oxadiazole, furan, 2 H-1,2,3-triazole, pyrrole and 1,2,5-thiadiazole) as corrosion inhibitors for copper immersed in oil-in-water (O/W) emulsions was investigated by weight loss, electrochemical tests, morphological characterization and theoretical calculations.

Findings

The orders of inhibition effect are furan < pyrrole < thiophene < 1,2,5-oxadiazole < 2H-1,2,3-triazole < 1,2,5-thiadiazole, and 1,2,5-thiadiazole at 0.5 mM has the best inhibition effect for copper immersed in emulsion. The results of scanning probe microscope, scanning electron microscope and electrochemical test show that a protective barrier can be formed on the surface of copper substrate with six corrosion inhibitors, thus effectively inhibiting the corrosion of copper mainly through chemisorption and following Langmuir’s adsorption isotherm.

Originality/value

Quantum chemical and molecular dynamic simulations demonstrate that all these compounds attached to Cu matrix with a flat-adsorption mode to prevent the emulsion corrode copper. Adsorbed inhibitors act as a barrier at Cu matrix to block corrosion and improve hydrophobicity.

Citation

Xiong, S., Si, J., Sun, J., Wu, H., Dong, H. and Zhang, C. (2020), "Experimental and computational studies on heterocyclic organic compounds as corrosion inhibitors for copper immersed in O/W emulsion medium", Anti-Corrosion Methods and Materials, Vol. 67 No. 2, pp. 214-227. https://doi.org/10.1108/ACMM-10-2019-2200