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Recent Patents on Materials Science
ISSN (Print): 1874-4648
ISSN (Online): 1874-4656
DOI: 10.2174/1874464811306010020

Ennoblement Due to Biofilms: Indicator for Potential Corrosion and Source of Electrical Energy

Author(s): Brenda J. Little, Jason S. Lee, Richard I. Ray, Shelton Austin and Justin C. Biffinger
Pages 20-28 (9)
Ennoblement, a positive shift in corrosion potential, due to biofilm formation is the basis of patents for biofilm monitoring and power generating devices. Ennoblement is a global phenomenon that is routinely cited as a mechanism for microbiologically influenced corrosion of some passive alloys. Increased corrosion is attributed to acceleration of the oxygen reduction reaction via several potential mechanisms that have been debated for decades. Because the phenomenon is predictable and reproducible at specific locations, ennoblement is the basis for patented methods and devices for monitoring biofilm formation and relating ennobled potentials to increased likelihood of corrosion and for evaluating cleaning and biocide treatments. Furthermore, when anodes and cathodes can be separated, as in a microbial fuel cell, biofilm formation on the cathode increases the potential difference between the two and the resulting power output. Most patented fuel cells using metal cathodes do not refer specifically to ennoblement in the disclosures.
Biofilms, ennoblement, microbial fuel cell, microbiologically induced corrosion, microbiologically influenced corrosion, oxygen reduction reaction, redox-active compounds, seawater battery, microbial film, MICROBE-BASED POWER SOURCES
Naval Research Laboratory, Code 7303, 1009 Balch Blvd, Stennis Space Center, MS 39529, USA.