A New Scanning Kelvin Probe Blister Test

The pressurized blister test is an excellent method to combine electrochemical reactions at polymer/metal interfaces with a mechanical load. It allows the application of a mechanical stress from a homogeneously pressurized electrolyte on the adhesive/metal interface in a sample geometry that is accessible for the HR-SKP [28]. Depending on the adjusted conditions, information on the synergy of mechanical stresses, elastic or inelastic deformations of the adhesive, transport processes, and corrosive reactions could be obtained with this method. 

As an example, an iron sample was coated with a two-component epoxy resin adhesive film 70 pm thick. A circular hole of 1 mm diameter in the pure iron substrate was prepared by a milling and chemical etching process. This procedure leads to an undamaged adhesive film above the hole. The hole could then be filled with an electrolyte and pressurized to establish a mechanical stress at the interface. Fig. 31.7 shows typical potential profiles in the vicinity of the hole in comparison with the topographic profile, both measured simultaneously with 

The financial support of the Bundesministerium fiir Bildung und Forschung is gratefully acknowledged. 

Johnson, M. Cappado-nia, M. Jauch, K. Doblhofer, Sensor Ac-tuat. B - Chem., 1993, 14, 741-742. 

Stratmann, A. Leng, W. Filrbeth, H. Streckel, H. Gehmecker, K. H. Grofie-Brinkhaus, Prog. Org. Coat., 1996, 27, 261-267. 

---