Investigations of Mussel Adhesive Proteins as Flash Rust Inhibitors
Journal of the Electrochemical Society
Several proteins found in the adhesive system of the common blue mussel Mytilus edulis have chemical properties which may enable them to inhibit the flash rusting of steels. In this work, Mytilus edulis foot proteins (MAPs) 1, 3, and 5 were isolated and applied to a high strength low alloy steel in a number of buffer systems containing varying amounts of borate, acetate, and phosphate at pH 5.5-7.0. Treated steel samples were then monitored in an exposure chamber at 40 • C and 100% relative
... d 100% relative humidity for 7 days. The MAP treatments were also evaluated using electrochemical impedance spectroscopy (EIS). The effect of enzymatic crosslinking of the applied proteins using mushroom tyrosinase was also investigated. Steel samples treated with MAP-1 did not inhibit corrosion when the protein was dissolved in deionized water, and the effect of MAP-1 dissolved in buffers containing acetate was not significantly different from control samples. However, when dissolved in 0.05 M phosphate buffer solution at pH 5.5, MAP-3 and MAP-5 were capable of significantly increasing the time to corrosion and significantly reducing the mass loss of the steel coupons in the exposure chamber compared with controls when treated with enzyme. The performance of the crosslinked MAP-5 was similar to a commercial flash rust inhibitor applied at the same mass concentration as the protein, suggesting that MAP-5 and similar proteins or polymers may be capable of inhibiting corrosion.