Multifunctional polyoxomolybdate ionic liquid coatings for mitigating microbiologically influenced corrosion
DOI: 10.1039/d5mh00373c
Mater. Horiz., 2025, 12, 4648–4661
Accepted: 7th May 2025
Mariella Malefioudaki, Archismita Misra, Nadja Sbeity, Juan Zueco-Vincelle, Miguel A. Laguna-Bercero, Andrea Koerdt, Rafael Martín-Rapún and Scott G. Mitchell
Abstract:
Corrosion of metals and other materials in marine environments poses significant economic, operational, safety, and environmental challenges across the oil and gas industry, the renewable energy sector, and maritime infrastructure. Microbiologically influenced corrosion (MIC) accounts for a substantial portion of this corrosion, with sulfate-reducing bacteria (SRB) and methanogenic archaea (MA) being key contributors. Conventional methods such as cathodic polarization have proven insufficient in mitigating the colonization of corrosive microbial communities in real marine environments, requiring the development of alternative, broad-spectrum antimicrobial strategies to prevent such biofilm formation. Recently, molybdate has emerged as a potential alternative to traditional biocides and nitrate. Our hypothesis is polyoxometalate-ionic liquids (POM-ILs), which exhibit antimicrobial and anticorrosion properties, could have a broader spectrum of antimicrobial activity than demonstrated until now and could be capable of shielding and protecting sensitive metal surfaces from the extreme acidic environments produced by MIC microorganisms. Here we show how two prototype polyoxomolybdate-based POM-ILs, [(CH3(CH2)6)4N]2[Mo6O19] and [(CH3(CH2)6)4N]4[Mo8O26], demonstrated antimicrobial activity at microgram per millilitre concentrations, prevented biofilm formation on metal surfaces, and provided resistance to corrosive acidic environments. Furthermore, impedance measurements were commensurate with electron microscopy studies showing that POM-IL-coated brass coupons withstood extremely corrosive environments. These proof-of-concept results demonstrate how multi-functional POM-IL coatings represent promising MIC mitigation solutions by providing a hydrophobic acid-resistant and biocidal protective layer that prevents biocolonisation and acidic corrosion by MIC microorganisms.
