In Situ Polymerized Self-Healing Microcapsules as Multifunctional Fillers toward Phosphate Ceramic Coatings.

Area of Science:

• Materials Science
• Corrosion Science
• Surface Engineering

Background:

• Chemically bonded phosphate ceramic coatings (CBPC) suffer from reduced protective efficacy due to micropores and poor self-healing in corrosive conditions.
• Enhancing corrosion resistance, wear performance, and self-healing is critical for phosphate ceramic coatings in demanding applications.

Purpose of the Study:

• To design and evaluate a novel self-healing phosphate ceramic coating with improved corrosion and wear resistance.
• To investigate the self-healing mechanism and the role of microcapsules in coating performance.

Main Methods:

• In situ polymerization of urea-formaldehyde (UF) microcapsules containing 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) within a phosphate ceramic coating matrix.
• Evaluation of corrosion resistance using electrochemical impedance spectroscopy and wear resistance through tribological testing.

Main Results:

• MC-PT@CBPC coatings (x = 0.5, 1.0, 1.5) demonstrated over 90% corrosion inhibition efficiency, with a 1-2 order of magnitude increase in impedance modulus compared to pure CBPC.
• The coatings exhibited active self-healing during prolonged immersion, attributed to PFDTES release and film formation, enhancing hydrophobicity and bonding.
• Improved hardness, reduced wear rate, and lower friction coefficient were observed due to the unique micronanostructure and lubricating PFDTES film.

Conclusions:

• The developed MC-PT@CBPC coatings offer excellent corrosion protection, tribological properties, and self-healing capabilities.
• The novel micronanostructure and in situ self-healing mechanism provide a promising approach for advanced protective coatings in harsh environments.