LB Films of Octadecanoyl Hydroxamic Acid as Barrier against Copper Corrosion

Free of ions of Octadecanoyl monohydroxamic acid (C18N) and in the presence of Fe3+ ion multilayers were deposited on the copper surface as Langmuir-Blodgett (LB) films. Their inhibiting effect on copper corrosion was investigated in 0.1 M sodium sulfate solution by different techniques such as potentiodynamic polarization and by electrochemical impedance spectroscopy (EIS). As well as that, the copper surfaces were visualized using a Scanning electron microscope (SEM). The results showed that the highest inhibition efficiency (92%) was achieved by LB film of 5 monomolecular layers of C18N/Fe3+. The LB films work as a cathodic inhibitor which inhibits the cathodic reaction. The presence of Fe3+ ions significantly improves the inhibition efficiency through the formation of a more compact dense layer of C18N/Fe3+ complex that blocks the flux of aggressive ions to the metal surface. The effect of immersion time on the inhibiting characteristics of LB films on the copper surfaces was studied.