Electrochemical impedance of a polymer-coated electrode with circular delamination around a defect site—II. Electrode with a fractal surface

✍ Scribed by Karel Micka

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 585 KB
• Volume: 38
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(93)80081-a

✦ Synopsis

Abtstract-A theory of electrochemical impedance was derived for a metal electrode with a fractaf surface covered with an insulating layer of an organic polymer containing scarcely distributed holes, through which an electrolyte penetrates, causing gradual loss of adhesion by electrocapilhuy effects. The potential distribution in the electrolyte layer under the insulating fRm during polarization with a small ac voltage is described by a parabolic differential equation which was solved analytically. The theory involves diiusion of an electroactive substance, charge transfer reaction, charging of the double layer and surface roughness. A good agreement was found between theoretical and measured impedance characteristics for the case without charge transfer reaction.