ACID-BASE PROPERTIES OF PASSIVE FILMS ON ALUMINUM II - AN X-RAY PHOTOELECTRON-SPECTROSCOPY AND X-RAY-ABSORPTION NEAR-EDGE STRUCTURE STUDY

The adhesion between metals and polymers has attracted much interest i n recent years due to the increasing use of metal/polymer assemblies, for example, in the fields of packaging, architecture, and automotive manufacturing. Among the parameters controlling the adhesion propertie s of metal/polymer systems, the acid-base properties of both materials appear to play an important role. Two methods are proposed for assess ing and quantifying the acido-basicity of passive films on metals: X-r ay photoelectron spectroscopy (XPS) and X-ray absorption near edge str ucture (XANES). These techniques were used here to characterize the ac id-base properties of a large set of passivated aluminum surfaces. Bot h XPS-monitored Fermi level shift and XANES formic acid and pyridine a dsorption measurements were found in good agreement in the establishme nt of a relative basicity scale for the studied surfaces. Moreover, th e results were cross-validated with those of the novel photoelectroche mical approach to the acid-base properties of aluminum surfaces presen ted in Part I.(1)