Copper Corrosion In Acidic Media Research Articles

Inhibition of Copper Corrosion in Acid Medium by Imidazole-Based Compounds: Electrochemical and Molecular Approaches

Chemically modified imidazole molecules: 4-(1H-imidazol-1-yl)aniline, 4-(1H-imidazol1-yl)benzaldehyde, 4-(1H-imidazol-1-yl)phenol and (4-(1H-imidazol-1-yl)phenyl)methanol were investigated as inhibitors of the copper (Cu0) corrosion in 0.5 mol L-1 H2SO4 medium. The electrochemical corrosion data were obtained by monitoring open circuit potential, linear potentiodynamic polarization and electrochemical impedance spectroscopy techniques, while the computational density functional theory (DFT) method was applied to correlate the electronic properties of the molecules with corrosion inhibition efficiencies. All molecules had inhibited the Cu corrosion, and the inhibition values lied between 80 and 94%. A good correlation between the inhibition efficiencies values and Gibbs adsorption energy was found, showing that the more negative Gibbs energy, better interaction between the corrosion inhibitor with the Cu0 surface, diminishing its corrosion in 0.5 mol L-1 H2SO4 medium. The DFT calculations showed significative differences in electronic and reactivity properties of imidazole and other molecules. The higher corrosion inhibition of imidazole derivates could be explained by electrophilic characteristic of these molecules, since there are empty molecular orbitals spread over mainly in benzene rings that make a metal-ligand charge transfer, receiving electronic density from the copper surface by backbonding, according to the electronic Fukui functions and the potential charge distribution considering the map of electrostatic potential.

Bee pollen extract as an eco-friendly corrosion inhibitor for pure copper in hydrochloric acid

Herein, bee pollen extract (BPE) was assessed for its performance as a green inhibitor of copper corrosion in acidic media. Gas chromatography mass spectrometry was used to identify the major components of BPE. Multiscale testing techniques, i.e. weight assessment, potentiodynamic polarisation tests, and electrochemical impedance spectroscopy, were employed to explore the corrosion properties of pure copper specimens in 1 M HCl with 0–7 g/L BPE. The adsorption of BPE on the copper surface fitted a Langmuir-type isotherm. BPE behaves as a mixed-type inhibitor that effectively decreases the corrosion of pure copper metal surfaces in 1 M HCl. Increasing the concentration of BPE increases its inhibition efficiency; at 7 g/L BPE, a high inhibition efficiency of 94.5% was attained. Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy were employed to analyse the copper surface. The inhibitive properties of BPE on pure copper corrosion are attributed to the adsorption of antioxidants and phenolic compounds on the copper surface. This study provides insight into the efficiency of BPE as a potential corrosion inhibitor of copper in acidic environments.

Experimental and theoretical studies on the inhibition properties of three diphenyl disulfide derivatives on copper corrosion in acid medium

2,2′-Dithiosalicylic acid (DSA), 2-aminophenyl disulfide (APD) and 2,2-dibenzamidodiphenyl disulfide (DPD) were determined for corrosion inhibition of Cu in H2SO4 media by electrochemical tests, surface morphology analysis, quantum chemical calculations and molecular dynamics simulations. The results of polarization curves showed that DSA, APD and DPD reveal good anti-corrosion capacity. They can simultaneously inhibit the cathodic and anodic reactions of copper. Therefore, they belong to the mixed-type corrosion inhibitors. Impedance spectroscopy results showed that when DSA, APD and DPD adsorption on the surface of Cu, the charge transfer resistance increases significantly and typical capacitance behavior produced, which indicates that the formed inhibitor film is very dense and ordered. In addition, the adsorption of corrosion inhibitors on the Cu surface is conforming to Langmuir monolayer adsorption. The experimental results obtained by surface topography analysis are consistent with the results of electrochemical experiments. Their corrosion inhibition ability is DSA < APD < DPD. Theoretical calculations further explore the relationship between corrosion inhibition performance and their molecular configurations.

Influence of the N-3 alkyl chain length on improving inhibition properties of imidazolium-based ionic liquids on copper corrosion

1-butyl-3-ethylimidazolium bromide ionic liquid, [beim]Br, was studied experimentally and theoretically as a potential inhibitor of copper corrosion in acidic media (pH = 3) by dc polarization, quartz crystal microbalance (QCM), scanning electron microscopy (SEM) and density functional theory (DFT). This ionic liquid is selected to study an effect of the alkyl chain length at the position N-3, since so far only ionic liquids with different alkyl substituents at the position N-1 are investigated. Improved inhibitory properties of the investigated ionic liquid against corrosion of copper in acidic solution at the given conditions are confirmed comparing to corresponding 1-butyl-3-methylimidazolium bromide ionic liquid. It is found that [beim]Br acts as a cathodic corrosion inhibitor, whereby its effectiveness depends on the applied concentration. The inhibitory effect of the studied ionic liquid (IL) was achieved through quick and spontaneous adsorption on the copper surface following the Langmuir's adsorption isotherm. Results obtained by SEM showed that copper protection is achieved through the less damaged copper surface in the presence of inhibitor. Applying DFT calculations, it is found that interactions with the metal surface occur by donating electron from the Br− anion to the copper. Based on the obtained Fukui functions influence of the inductive effect of ethyl/methyl group on the inhibitory activity is also discussed.

Piezogravimetric investigation of heterocyclic compounds as potential inhibitors against copper corrosion in acidic media

Piezogravimetric investigation of heterocyclic compounds as potential inhibitors against copper corrosion in acidic media

The synergistic mechanism of phytic acid monolayers and iodide ions for inhibition of copper corrosion in acidic media

Electrochemical and Raman observations show synergistic inhibition of phytic acid and I− for copper from corrosion in acid solution.

Inhibition Effect of Rhodanine-N-Acetic Acid on Copper Corrosion in Acidic Media

The inhibition effect of Rhodanine-N-acetic acid (R-NA) on copper corrosion in acidic media is studied by using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and linear polarization resistance (LPR). The surface morphology is investigated by using scanning electron microscopy (SEM). The exposure of copper surface to 0.5 M H2SO4 solution in short and long immersion times in the absence and presence of the inhibitor is also examined. The results show that R-NA is a powerful inhibitor for copper corrosion in acidic media due to its strong adsorption onto the metal surface. Moreover our results are compared with similar compounds in the literature.

EQCM study of copper and iron corrosion inhibition in presence of organic inhibitors and biocides

Attention has been devoted to the application of quartz crystal microbalance (QCM) in the field of corrosion and corrosion inhibition. In-situ measurements were performed on copper and iron surfaces. Copper corrosion inhibition by the application of several inhibitors was followed by QCM. Copper corrosion inhibition in different electrolyte solutions such as acidic sodium sulphate and neutral sodium chloride were investigated. Different inhibitor compounds were tested for protection against copper corrosion. Three different groups of inhibitors were investigated; aromatic sulfoxides, benzo-hydroxamic acid derivatives, and azole derivatives. Among the tested sulfoxides, di-benzyl-sulfoxide (DBSO) produced the best protection, while p-chloro-benzo-hydroxamic acid showed excellent protection among the benzo-hydroxamic acid derivatives. Among the tested azole derivatives, 5-mercapto-1-phenyl-tetrazole (5-McPhTT) and 5-(4′-isopropylbenzylidene)-2,4-dioxotetrahydro-1,3-thiazole (5-IPBDT) showed excellent inhibition properties against copper corrosion in acidic media. The effect of biocides, namely N-hydroxyalkylated amino acids, on biofilm formation has been investigated, too. From the attained results, it is clear that QCM is an essential tool for obtaining important information on corrosion inhibition and its mechanism.