In a previous investigation1 the effect of benzotriazole (BTA) on corrosion of copper in 5% NaCl was studied by immersion test, potentiostatic polarization, alternating current impedance measurements, and ellipsometric investigations. It was found that BTA present in the corrosive environment is a good corrosion inhibitor, confirming earlier results by Cotton and coworkers.2,3 The ellipsometric data were consistent with a film of BTA growing to 40Å in approximately 45 minutes and indicated that the initial film formed on Cu in aerated 5% NaCl consists of an adsorbed layer of BTA. After about 7 hours the film had grown only slightly to 60Å. These results were not in agreement with data by Poling4 who, using infrared reflectance techniques, found films up to 4200A thick after 2 hours exposure to 3% NaCl containing 0.02 M BTA at pH3 without agitation.
Since it is possible that the differences between previous results...
