Dissolution Behavior of Iron in Contact with Frozen Electrolyte Solutions

The dissolution behavior of ferrous ions from a pure iron wire in contact with highly-concentrated salt solutions co-existing with ice was visually analyzed. The dissolved ferrous ions complexed with 1,10-phenanthroline doped in the solution, and the resultant coloration was quantitatively evaluated employing a combination of microscopy and image processing. To provide a dimension-controlled solution area, a microchannel was fabricated in bulk ice, and the highly concentrated solutions were filled therein. The effects of various ionic species on the dissolution behavior were studied. We found that dissolution was significant when the wire was in contact with metal chloride solutions, whereas dissolution was not observed with iodide or bromide salt solutions.