Dual‐Loading Strategy Constructing Smart Coatings With Novel Hydroxyapatite/ZIF‐8 Composites

Abstract

The marine environment with high humidity and salinity poses higher requests on the service life of traditional polymer coatings therefore, various fillers have been developed for modification. Smart coatings built by fillers that possesses passive barrier and active self‐healing properties show considerable prospects in metal protection. Herein, we applied a novel dual‐loading strategy to design tannic acid (TA) decorating hydroxyapatite (HAp)/zeolite imidazole framework (ZIF‐8) loading 2‐amino benzothiazole (2‐ABT) composite fillers. The epoxy coating (EP) doped with ABT@ZIF8‐HAp@TA (AZHT/EP) presented hydrophobicity and improved mechanical performance on Q215 steel. Moreover, the |Z|f=0.01Hz of AZHT/EP after immersion in saline water for 28 days (6.24 × 1010 Ω•cm2) is higher than pure EPs with two magnitudes. The anticorrosion mechanism of the AZHT/EP was proposed based on the analysis of corrosion products. To conclude, the dual‐loading strategy has considerable potential in designing smart coatings for corrosion protection in harsh environments.