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In-Situ Imaging of Chloride Ions at the Metal/Solution Interface by Scanning Combination Microelectrodes.


pdf icon In-Situ Imaging of Chloride Ions at the Metal/Solution Interface by Scanning Combination Microelectrodes. (931 K)
Lin, C. J.; Du, R. G.; Nguyen, T.

Corrosion, Vol. 56, No. 1, 41-47, January 2000.

Keywords:

chloride ion; ion selective microelectrode; imaging; interface; microelectrode; solution/metal

Abstract:

Combination solid silver-silver (Ag/AgCl) and liquid membrane Cl- ion-selective microelectrodes have been designed and constructed. These microelectrodes, which have a micrometer size tip, contain two compartments, one serves as the reference electrode and the other as the Cl- ion-selective electrode. The microelectrodes have been used to map in situ Cl- ion distribution in several localized corrosion systems. When used with a computerized scanning stage, the microelectrodes can provide information on the distribution of Cl- ions near the metal/electrolyte interface. Cl- ions were observed to migrate towards, and accumulate near, the anodic region forming a "chloride ion rich island" on the metal surface. Scanning combination Cl- ion-selective microelectrodes may provide a useful tool for mechanistic studies of localized corrosion.