4-Phenylpyrimidine monolayer protection of a copper surface from salt corrosion

Corrosion Inhibition Effect of Pyridine-2-Thiol for Brass in An Acidic Environment

In this study, the inhibitive performance of pyridine-2-thiol added to a corrosive solution was investigated for brass using potentiodynamic polarization, electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy. Electrochemical experiments were performed with different inhibitor concentrations in 0.5 M H₂SO₄ as the corrosive medium. For potentiodynamic polarization, i_corr values decreased significantly for the inhibited solutions in contrast with the uninhibited solution. Pyridine-2-thiol had an optimum inhibition concentration of 0.25 mM, giving an i_corr value of 1.8 µA/cm² compared to 26 µA/cm² for the blank solution. EIS data indicated that R_p and R_ct values increased substantially after the addition of the corrosion inhibitor and corrosion inhibition efficiencies of more than 85% was achieved for the majority of the inhibited solutions. Scanning electron microscopy showed defect free and less scale formation for the inhibited surface but the bare brass surface had larger amounts of scale formation. X-ray photoelectron spectroscopy and UV-vis spectroscopy was used to investigate surface chemical composition and inhibitor structural changes over time.

Influence of 5-Chlorobenzotriazole on Inhibition of Copper Corrosion in Acid Rain Solution

This paper aims to examine the efficiency of 5-chlorobenzotriazole (5Cl-BTA) as a copper corrosion inhibitor in acidic rain solutions with a pH value of 2.42 by the electrochemical polarization method. 5-Chlorobenzotriazole acts similar to a mixed type inhibitor, according to the potentiodynamic polarization measurements. Results obtained in this research suggest that 5Cl-BTA is a good inhibitor; it decreases anodic and cathodic reaction rates, and the highest inhibition efficiency was 91.2%. The inhibitory effect of 5-chlorobenzotriazole is explained by the formation of the layer on the copper surface. Stability of the protective layer increased with inhibitor concentration. Scanning electron microscopy and energy-dispersive analysis of X-rays analysis confirmed that on the electrode surface, a protective layer was formed. Adsorption of 5Cl-BTA obeys the Langmuir adsorption isotherm. 5Cl-BTA showed good inhibitory characteristics even when the Cl^- ions were present in examined solutions.

Ibuprofen as a corrosion inhibitor for copper in synthetic acid rain solution

It is known that if unused drugs are improperly disposed, they can pollute the environment. Furthermore, researchers are still trying to find an environmentally friendly corrosion inhibitor. These factors lead to the possible application of unused pharmaceutical compounds as corrosion inhibitors. The feasibility of an anti-inflammatory, analgesic and antipyretic drug, ibuprofen, was evaluated as a potential copper corrosion inhibitor in synthetic acid rain solution. This investigation was performed by applying electrochemical and weight loss measurements and quantum chemical calculations. The results obtained by these techniques revealed the ability of ibuprofen to protect copper from corrosion. The inhibition efficiency of ibuprofen rises with increase in its concentration and can reach a value of 97.3%. The results of surface analysis of treated coupons by scanning electron microscopy and theoretical calculations are consistent with the experimental results.