Ion exchange and corrosion behaviour of polyaniline coated mild steel electrode

The corrosion behaviour of mild steel and mild steel covered by the electrodeposited polyaniline films was investigated by electrochemical impedance spectroscopy. The electrodeposition of polyaniline coatings on mild steel was carried out by cyclic voltammetry using oxalic acid as the electrolyte. Protective properties of polyaniline coatings were investigated by monitoring the open-circuit potential and by applying electrochemical impedance spectroscopy. Nyquist plots explained as assuming underfilm oxidation at high frequency region and ion exchange process between polyaniline and electrolyte interface performed by oxygen reduction at low frequency region. Polyaniline layer provides corrosion protection due to having high ion exchange polarization resistance between the film and the electrolyte solution

Corrosion inhibition of brass in presence of terdentate ligands in chloride solution

WOS: 000228625600015The inhibition of two terdentate ligands, 2-[(E)-pyridin-2-ylimino)methyl)]phenol and 2-[(pyridin-2-ylamino)methyl]phenol, abbreviated L, and L, respectively, on the corrosion of brass in 0.10 M NaCl solution under various conditions, has been studied by means of the potentiostatic polarization and AC impedance methods. The studies show that terdentate ligands, L-1 and L-2 inhibit the corrosion of brass in chloride solution and that the inhibiting efficiency increases with an increase in their concentrations. Self-assembled films of these substances were also prepared on the brass surface. These films improved significantly the protecting ability of brass surface to corrosion in 0.10 M NaCl solution. When the films were modified with benzotriazole (BTA), the quality and corrosion resistance of films improved markedly. (c) 2004 Elsevier Ltd. All rights reserved

Electrooxidation of physostigmine at different electrodes

824-829The elcctrooxidation of physostigmine (PHY) has been investigated at different pH values at platinum, ruthenium, carbon paste and glassy carbon electrodes. It has been found that Ru and Pt electrodes played an important role in the oxidation. The nature of the curves are strongly dependent upon the scan rate, supporting electrolyte and the pH values of the solutions. With glassy carbon electrode, the results are highly dependent upon the activation process of the  electrode. Activated glassy carbon and oxidized Pt and Ru electrodes give the best results. Suitable mechanisms for oxidation of PHY in both acidic and basic media have been proposed