pH Mapping of Localized Corrosion in Confined Electrolytes by Total Internal Reflexion Fluorescence Microscopy

摘要

A device for pH mapping derived from optical sensors similar to TIRFM (Total Internal Reflection Fluorescence Microscopy) has been developed for future possible applications in the field of localized corrosion. The basic principle of this sensor is based on the excitation of a fluorescent silica polymer film of nanometer dimensions, deposited by sol-gel method on a waveguiding layer. Using this sensor as a crevice former the pH changes have been recorded for a cavity machined in a Fe-17%Cr electrode for different sizes of gap.