Detection of the Oxidation Area by Spectrophotometry: Regional and Temporal Changes in Anodic Oxidation on Titanium in Bipolar Electrochemistry

This study investigated the temporal change in the oxidationareaon a titanium (Ti) bipolar electrode (BPE) subjected to bipolar anodizationin a direct current (DC) electric field using a spectrophotometer.The rectangular Ti sheet used as a BPE was horizontally positionedat the center of a cell. After the DC bipolar anodization, the oxidizedarea was detected nondestructively and visually using a specific interferencecolor that depends on the thickness of the barrier-type oxide filmformed on the Ti BPE. The change in the L*a*b* color space corresponding to eachinterference color revealed that the oxidation area increased alongthe longitudinal axis of the BPE with the increasing electrolysistime by reflecting the change in the potential distributions on theBPE. As visually demonstrated, the area where the anodic reactionproceeded reached saturation at 90% of the BPE surface area.

Automated summary

This study investigated the temporal change in the oxidation area on a titanium bipolar electrode (BPE) during bipolar anodization. The oxidized area was detected nondestructively using a specific interference color that depends on the thickness of the oxide film. The results showed that the oxidation area increased along the longitudinal axis of the BPE with increasing electrolysis time, reaching saturation at 90% of the BPE surface area.