STUDY OF CORROSION INHIBITION OF COPPER IN 0.1 M NACL USING THE EQCM TECHNIQUE

The inhibition of Cu corrosion;in 0.1 M NaCl solution was studied usin g the EQCM technique. Some organic compounds, at 10(-3) M concentratio n, were tested as inhibitors. The inhibiting effect of these additives was evaluated by recording the anodic and cathodic polarization curve s on Cu, electroplated on quartz crystals. At the same time the mass c hanges of the electrode, as a function of the potential, were recorded . The formation of the protective film during immersion in distilled w ater or 0.1 M NaCl solution containing the inhibitors was followed by variation of the EQCM frequency. The protective characteristics of the se films were evaluated by the mass variations of the electrode immers ed in 0.1 M NaCl solution and by the voltammograms recorded after 1 mi n or 5 h immersion in 0.1 M NaCl solution. FTIR reflection spectra wer e recorded on Cu sheets immersed for 1 or 60 min in NaCl solution in t he presence of inhibitors. They showed a very rapid interaction betwee n metal surface and organic molecule. The results obtained allow us to conclude that EQCM technique has a valuable part to play in the inter pretation of corrosion and corrosion inhibition mechanisms. (C) 1998 E lsevier Science Ltd. All rights reserved.