In Situ Fluorescence Imaging of Localized Corrosion with a pH-Sensitive Imaging Fiber

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• 作者：Anna A. Panova ; Paul Pantano ; and David R. Walt
• 刊名：Analytical Chemistry
• 出版年：1997
• 出版时间：April 15, 1997
• 年：1997
• 卷：69
• 期：8
• 页码：1635 - 1641
• 全文大小：388K
• 年卷期：v.69,no.8(April 15, 1997)
• ISSN：1520-6882

文摘

A fiber-optic pH-imaging sensor array capable of bothvisualizing remote corrosion sites and measuring localchemical concentrations at these sites was applied to real-time corrosion monitoring. The imaging fiber's distalface,containing an immobilized pH-sensitive fluorescent dye,was brought into contact with metal surfaces submergedin aqueous buffers and fluorescence images were acquired as a function of time. Heterogeneousfluorescencesignals were observed due to both pH increases atcathodic surface sites and pH decreases at anodic surfacesites. These fluorescence signals showed bothlocalizationand rates of corrosion activity. Three corrosionprocesseswere investigated, galvanic corrosion at a copper/aluminum interface and crevice corrosion and pitting at astainless steel surface. The spatial resolution ofthetechnique was limited by proton/hydroxide diffusion andthe diameter of the individually clad optical fibers comprising the imaging bundle.