engleski

INFLUENCE OF THE PH VALUE ON THE INHIBITING ACTION OF 1- PHENY- 4- METHYLIMIDAZOLE

The aim of this work was to follow the influence of the pH value of the solution on the efficiency of 1-phenyl-4-methyl imidazole as a copper corrosion inhibitor in chloride media. Studies were performed in 0.5 M NaCl solutions with pH ranging from 1-7. The structure and properties of inhibitor layer formed in chloride aqueous solution was studied as well as the morphology and protectiveness of inhibitor layer formed from THF solution of 1-phenyl-4-methyl imidazole. Electrochemical properties of differently formed inhibitor layers were studied by electrochemical methods: potentiodynamic polarization (from which the corrosion current was determined by Tafel extrapolation method) and electrochemical impedance spectroscopy. The morphology of copper samples exposed to chloride solutions of different pH, with or without the studied inhibitor, was monitored with AFM. The investigated inhibitor 1-phenyl-4-methyl imidazole forms very protective, polymer-like, layer on copper surface in neutral chloride solutions. In solutions with lower pH value the morphology of this layer changes, as well as it’ s protecting properties

copper; corrosion inhibitors; imidazole; AFM; electrochemical methods

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