Using Three-Electrode Electrochemical Impedance Spectroscopy Sensors to Monitor Paint Degradation in Seawater
Open Access
- Author:
- Terosky, Justin
- Graduate Program:
- Engineering Science and Mechanics
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 17, 2023
- Committee Members:
- Albert Segall, Program Head/Chair
Barbara Shaw, Thesis Advisor/Co-Advisor
Elzbieta Sikora, Thesis Advisor/Co-Advisor
Suzanne E Mohney, Committee Member - Keywords:
- Corrosion
Electrochemical Impedance Spectroscopy - Abstract:
- Corrosion and the associated maintenance cost the United States Navy an estimated amount of over $4 billion annually [1]. The primary protective measure against corrosion in seafaring vessels is anti-corrosive paint coatings, and therefore monitoring the health of these coatings would allow more productive and cost-effective maintenance. Using Electrochemical Impedance Spectroscopy (EIS) testing, breakdown of painted coatings can be detected before it becomes visually apparent. Due to this, thin-film Ag/AgCl electrodes along with a small potentiostat and computer interface would allow for effective, modular corrosion-detecting devices. These sensors could be used to monitor the health of the anti-corrosive coatings on Navy Ships, which would reduce maintenance time and costs, and increase the safety and lifespan of these vessels. To determine whether these sensors would be able to collect usable data, a small, corrosion-resistant fixture was developed on which to mount panels coated in Army Chemical Agent Resistant Coating (CARC) with thin-film Ag/AgCl electrodes attached. Atmospheric corrosion data collected during rural atmospheric exposure in the Pennsylvania State University Atmospheric Corrosion Testing Site and marine atmospheric exposure in Redington Beach, Florida was used to determine the reliability of these applique sensors over time. A variety of corrosion-monitoring metrics were also evaluated to determine useful metrics for evaluating the health of these coatings. It was found that the applique electrodes were able to perform consistently with respect to control testing, and the metrics determined to be the most useful for determining the health of coatings using EIS were: low-frequency (~50 mHz) impedance, difference in magnitude of impedance over various frequency ranges, and, when zinc is present in a coating, open circuit potential.