Synthesis, Characterization, and Utilization of Iron II Ion Sensing Fluorescent Probes for Detection of Early Onset Anodic Corrosion

Corrosion effects can be seen in infrastructure all around the world. From rusted bridges, ships, and other steel surfaces, the price of corrosion adds up quickly with repairs, maintenance, and complete replacement. Common approaches to corrosion detection and prevention require slow, optical inspection to begin the repair and maintenance process, which can also be very slow and costly. However, recent literature suggests that metal chelating probes can yield new understanding of the processes of corrosion faster and with greater specificity in location and diversity in mechanisms for early onset of corrosion. Earlier corrosion detection can be characterized by several ways. One method, fluorescence, is a tool used to detect, quantify and observe corrosion. The work provided in this document focuses specifically on a pyrene-TEMPO species that becomes fluorescent by the donation of electrons from metal ions (namely iron II) that are generated at anodic sites in the corrosion process. By observing these events, we will be able to qualitatively detect the early onset of corrosion and potentially quantitatively monitor early corrosion, which would allow for improved timing for maintenance and repairs and less costly repair processes for coated steel substrates. Herein, we report the synthesis, characterization, and utilization of the pyrene-TEMPO species in the solution state, solvated resin state, and final glassy matrix coated state. We report the effect of these three solution and polymer physical states on fluorescence intensity as well as emission wavelengths with and without Fe2+