Barnacle Cement Protein: An Efficient Bioinspired Corrosion Inhibitor

Abstract

To prevent corrosion damage in aggressive environments such as seawater, metallic surfaces are usually coated with corrosion inhibitors typically made of organic molecules. Unfortunately, these inhibitors generally exhibit environmental toxicity, affecting living organisms and leaving harmful chemicals in natural habitats. Thus, there is a strong need to develop greener corrosion inhibitors that are chemically and mechanically robust but do not leach toxic chemicals. Here, we show that the recombinant protein r MrCP20 from the adhesive cement protein of the barnacle Megabalanus rosa efficiently protects AH36 steel against corrosion under high salt conditions mimicking the marine environment. We reveal that these anti-corrosion properties are linked to the protein’s biophysical properties, namely its strong adsorption to surfaces combined with its interaction with free Fe ions released by steel substrates, which form a stable layer that increases the coating’s impedance and delays corrosion. Our findings highlight the synergistic action of r MrCP20 in preventing corrosion and provide molecular-level guidelines to develop alternative green corrosion inhibitor additives.