Synergetic Inhibition and Corrosion-Sensing Abilities Based on pH-Sensitive ZIF-8@CeO₂ Core-Shell Nanocontainers...

Area of Science:

• Materials Science
• Corrosion Science
• Nanotechnology

Background:

• Developing advanced anticorrosion coatings with integrated sensing and self-healing capabilities is crucial for extending material lifespan.
• Existing coatings often lack real-time monitoring and rapid response mechanisms for corrosion initiation.

Purpose of the Study:

• To design and synthesize novel nanocontainers for multifunctional anticorrosion coatings.
• To integrate stimuli-responsive release of corrosion inhibitors and indicators for early detection and active protection.

Main Methods:

• Fabrication of core-shell hollow mesoporous cerium oxide (HMCM) microspheres functionalized with zeolitic imidazolate framework (ZIF-8).
• Loading of 1,10-phenanthroline (Phen) as a corrosion indicator/inhibitor into the ZIF-8@HMCM nanocontainers.
• Incorporation of ZIF-8@HMCM-Phen nanocontainers into a waterborne epoxy polymer (WEP) coating.
• Evaluation of corrosion resistance using electrochemical impedance spectroscopy (EIS) and immersion tests.

Main Results:

• ZIF-8 functionalization significantly increased the specific surface area and Phen loading capacity of the nanocontainers.
• The ZIF-8@HMCM-Phen nanocontainers demonstrated stimuli-responsive release of Phen at corrosion sites, enabling visual detection of corrosion initiation via red coloration.
• The ZIF-8@HMCM-Phen/WEP coating exhibited superior corrosion resistance, with |Z|0.01 Hz values over an order of magnitude higher than pure WEP after 80 days of immersion.
• Scratched coating samples showed a visual response within 15 minutes, indicating rapid early corrosion identification.

Conclusions:

• The developed ZIF-8@HMCM-Phen nanocontainers provide a practical platform for creating smart anticorrosion coatings.
• These coatings offer concurrent functions of corrosion monitoring, active inhibition, and self-healing.
• The strategy presents a significant advancement toward durable and intelligent protective materials.