Epoxy Composite Coating with Excellent Anti-Corrosion and Self-Healing Properties Based on Mesoporous Silica Nano-Containers

Abstract

Anti-corrosion coating containing smart nano-containers which load inhibitors is playing an increasingly important role in extending the lifetime of metal coating or slowing down metal corrosion. Whereas, the low loading amount of the inhibitors in the nano-containers limits its application. In this work, mesoporous silica (SiO2) nano-material was prepared and designed as a container in which AMT inhibitor was loaded. The prepared materials were further modified and used as additives in the anti-corrosion epoxy coating. The results showed that the loading capacity of AMT inhibitors could reach to 36% and the release amounts of AMT from SiO2-based nano-containers gradually increased as the pH of the system decreased. When the pH was 3, 5, and 7, the release rate of AMT was 92.3%, 73.6%, and 50.2% respectively indicating that the stronger acidic system could exacerbate the damage of metal, but the increasing release amounts of inhibitors could effectively slow down the metal corrosion. The release behavior experiments ensured that the epoxy composite coating doped nano-containers could exhibit self-healing function under the different acidic conditions. In addition, EIS results also showed that the epoxy composite coating showed excellent anti-corrosion property and self-healing performance in harsh environment.

Keywords: Mesoporous silica, 2-Amino-5-mercapto-1, 3, 4-thiadiazole, Self-healing, Anti-corrosion