Advanced surface analysis using GCIB-C60++-tandem-ToF-SIMS and GCIB-XPS of 2-mercaptobenzimidazole corrosion inhibitor on brass

Abstract

A gas cluster ion beam (GCIB) sputtering source in association with high-resolution X-ray photoelectron spectroscopy measurements were employed to slowly sputter and analyze a 2-mercaptobenzimidazole (MBIH) corrosion inhibitor surface layer on brass substrate after immersion in chloride solution. Furthermore, ToF-SIMS measurements and imaging were performed to further describe the structure of this surface layer. In addition, the powerful nature of the tandem ToF-SIMS (MS/MS) technique was demonstrated to detect and confirm the organometallic complexes that formed among the brass corrosion products and MBIH. Also, the issue of spectral interferences was considered for the organometallic complexes of 63Cu, 65Cu, 64Zn, and 66Zn in combination with MBIH. Large-area ToF-SIMS imaging (4.8 by 3.2 mm) in positive and negative polarities was performed to show the 2D distribution of the MBIH on the brass surface. Finally, 3D ToF-SIMS imaging using GCIB and C60++ sputtering sources showed the depth distribution of different species at the MBIH/brass interface. This type of analytics is currently state-of-the-art in the surface analysis of corrosion inhibitors.