A High-Performance Anti-Corrosive Epoxy Coating Based on Ultra-Thin Hydroxyapatite Nanosheets with pH-Responsive...

Area of Science:

• Materials Science
• Corrosion Science
• Nanotechnology

Background:

• Increasing demands for long-term anti-corrosion coatings in challenging environments.
• Emergence of intelligent coatings to meet these advanced requirements.

Purpose of the Study:

• To enhance the anti-corrosion performance of epoxy resin coatings.
• To develop an intelligent coating utilizing modified nanocontainers for improved corrosion resistance.

Main Methods:

• Grafting beta-cyclodextrin (β-CD) onto hydroxyapatite (HAp) nanoparticles using a silane coupling agent.
• Encapsulating benzotriazole (BTA) within the β-CD/HAp nanocontainers.
• Embedding the modified nanocontainers into an epoxy resin matrix.

Main Results:

• The developed coating exhibited excellent corrosion resistance in immersion and scratch tests.
• A low-frequency impedance value of 6.28 × 10^7 Ω cm^2 was maintained after 30 days of immersion.
• The coating formed an inert protective layer through the reaction of released corrosion inhibitor with corrosion products.

Conclusions:

• The intelligent coating provides enhanced passive barrier function via HAp nanoparticles.
• The β-cyclodextrin component imparts a pH-responsive active corrosion inhibition mechanism.
• The combined functionalities result in superior anti-corrosion capabilities in aggressive environments.