Eco-friendly silane as corrosion inhibitor for dual self-healing anticorrosion coatings

Abstract

Corrosion resistance and active protection performance of organic coatings can be improved by incorporation of corrosion inhibitor-loaded nanocontainers. Herein, 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (FTES) as a green corrosion inhibitor was encapsulated in hollow mesoporous silica (HMS). FTES-loaded HMS (FHMS) was embedded in an epoxy coating on the surface of the magnesium (Mg) alloy. Artificial defect in FHMS-loaded epoxy coating was made by needle punching. The long-term anticorrosion behavior and self-healing properties of the modified coating were evaluated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). In all cases, FHMS can enhance corrosion resistance of the epoxy coating. Among all the FHMS-loaded coatings, the coating containing 0.5 wt% FHMS (FHMS-0.5%) still exhibits excellent corrosion protection performance after 2688 h of immersion. Meanwhile, it shows superior self-healing ability in the scratched areas. These are attributed to the fact that FTES released from HMS nanoparticles can interact with the epoxy coating and the Mg alloy substrate. Moreover, FTES silane can also form a crosslinked Si-O-Si network by itself.