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Local potentials under electrolyte droplets on steel
Author(s) -
Meijers Steven,
Lauterbach Martijn,
Wit Hans,
Droog John
Publication year - 2000
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.200005724
Subject(s) - electrolyte , kelvin probe force microscope , cathodic protection , drop (telecommunication) , anode , cathode , chemistry , voltage drop , chemical physics , corrosion , analytical chemistry (journal) , materials science , nanotechnology , metallurgy , thermodynamics , electrode , current (fluid) , atomic force microscopy , electrical engineering , chromatography , physics , engineering
The scanning Kelvin probe shows great potential for the study of localised corrosion phenomena on coated metals. However, it still is difficult to unravel the contributions of the different components of complex coating systems to the measured Volta potentials. Experiments on simple model systems are necessary to increase our knowledge. The classical Evans drop experiment was chosen as such a model system. Using the scanning Kelvin probe potential distributions in the drop were measured. It was found that within the droplet no separate anode and cathode can be distinguished in the potential profile. A cathodic region was found just outside the droplet, where a very thin electrolyte layer exists. Twin drop experiments however showed potential differences in electrolyte over short distances.