In situ and ex situ studies of imidazole and its derivatives as copper corrosion inhibitors II. AC impedance, XPS, and SIMS studies

The objective of this work was to investigate the efficiency of imidazole d erivatives for corrosion inhibition of copper in 0.5 M hydrochloric arid. C orrosion inhibition was studied using impedance spectroscopy. Imidazole and its derivatives 4-methylimidazole, 4-methyl-5-hydroxymethylimidazole, 1-ph enyl-4-methylimidazole, 1-(p-tolyl)-3-methylimidazole were investigated. Th ese studies have shown that 1-(p-tolyl)-4-methylimidazole is the best inhib itor in this series and that it acts as mixed inhibitor. The nature of the chemical interaction between these molecules and the copper surface was inv estigated for Cu exposed to solutions having two very different pH values: 0.5 M HCl and unbuffered purified water. X-ray photoelectron spectroscopy a nd secondary ion mass spectrometry were used to explore the nature of the i nteraction. Possible mechanisms of corrosion inhibition for these molecules are discussed. (C) 2000 The Electrochemical Society. S0013-4651(99)07-046- 9. All rights reserved.