WETTABILITY OF METALLIC OXIDES - APPLICATION TO STAINLESS-STEEL ACID-BASE PROPERTIES

The Bronsted acid-base properties of oxides of metallic systems are in vestigated by contact angle measurements of water droplets for differe nt pH. Theoretical analysis based on the electrical and chemical varia tions of the solid/liquid interfacial tension allows to understand the experimental results observed on model oxide surfaces as SiO2 and Al2 O3. Similar wetting measurements are performed on the passive films of a model Fe-Cr-Si alloy and 304 stainless steel. Significant correlati ons are observed between the contact angle-pH curve and the oxide comp osition of the passive films deduced from XPS analysis.