Self-healing coating for carbon steel extends lifespan in marine environments, reducing embodied carbon

Researchers developed a stress-responsive self-healing coating for Q235 carbon steel used in marine environments. The coating uses hollow mesoporous silica nanoparticles modified with titanium dioxide and loaded with sodium phytate, a bio-based corrosion inhibitor. When mechanical stress reaches 50% of yield strength, the coating releases the inhibitor at micro-damage sites, forming a protective film that restores corrosion resistance in place. In 18-day immersion tests with saltwater, the coating maintained an impedance modulus around 4500 ohm-cm2 and showed increasing protection from day 5 onward. The titanium dioxide modification also improved tensile strength by 24% and blocked chloride penetration. Longer-lasting steel components mean less frequent replacement, lower material demand, and reduced embodied carbon in marine infrastructure, offshore wind, and port facilities.