ADSORPTION OF MONOETHANOLAMINE ON CLEAN, OXIDIZED AND HYDROXYLATED ALUMINUM SURFACES - A MODEL FOR AMINE-CURED EPOXY ALUMINUM INTERFACES

The interaction of 1-amino-2-hydroxyethane (monoethanolamine) with clean Al(100), in-situ oxidized Al(100) and in-situ hydroxylated Al(100) has been investigated using Auger electron spectroscopy (AES) and high-resolution electron energy-loss spectroscopy (HREELS). It has been shown that, on all these surfaces, adsorption of monoethanolamine can be interpreted in the framework of the Hard and Soft Acid Base (HSAB) principle. However, the detailed mechanism differs for each surface: (i) monoethanolamine interacts with clean Al(100) through its amine termination via a Lewis-like acid-base reaction; (ii) monoethanolamine interacts with oxidized Al(100) through its alcohol termination via a Lewis-like acid-base reaction; (iii) monoethanolamine interacts with hydroxylated Al(100) through its alcohol termination via a Bronsted-like acid-base reaction.