Probing the corrosion resistance of a smart electroless Ni-P composite coating embedded with pH-responsive corrosion inhibitor-loaded nanocapsules
By Li, Jiankuan; Zeng, Hongbo; Luo, Jing-Li
Published in Chemical Engineering Journal
Chemical Engineering Journal
2020
Abstract
A smart electroless Ni-P composite coating incorporated with pH-responsive benzotriazole (BTA)-loaded nanocapsules was successfully fabricated and applied on N80 carbon steel for the first time, and the improved corrosion resistance was evaluated by electrochemical measurements and surface characterization techniques. The coating incorporated with the functionalized nanocapsules exhibits excellent anti-corrosion performance in the CO2-saturated brine. This is originated from the filling of the nanocapsules into intrinsic micropores of the coating, which impairs the electrolyte penetration at the beginning stage of immersion, and the release of BTA when triggered by the local acidification of the micropores due to penetration of aggressive medium as immersion further proceeds. Furthermore, the incorporated nanocapsules endow the smart coating with a good anti-corrosion stability, showing a maximum inhibition efficiency of over 80%. The well-protected coating surface shows much less corrosion pits and no evidence of lateral coating disbondment at the coating/substrate interface according to the surface characterization results.