Anti-corrosion coating within a polymer network: Enabling photothermal repairing underwater

Designated repairing of a damaged anti-corrosion coating underwater remains a big challenge because of the requirements on both fluidity and stability of the coating in water during repairing, as well as the water resistance for corrosion prevention. Herein, we develop a novel composite coating by confining the paraffin wax (PW) within a polypropylene (PP) network fabricated through thermally induced phase separation (TIPS). Integrating with the carbon-based photothermal agents, PW experiences a solid-to-liquid transition at an elevated temperature caused by photothermal effect and flows across the PP network to the damaged region. The PP network plays a crucial role in preventing the detachment of molten PW from the substrate by reserving it through capillary and hydrophobic interactions. Such a bicontinuous structure enables fast, designated and repeatable insitu repairing underwater under a near-infrared (NIR) laser, and the coating exhibits outstanding corrosion resistance before damage and after repairing.

Automated summary

Researchers have developed a novel composite coating by confining paraffin wax within a polypropylene network through thermally induced phase separation. By integrating carbon-based photothermal agents, the paraffin wax undergoes a solid-to-liquid transition at an elevated temperature caused by photothermal effect and flows to the damaged region, ensuring fast repair underwater. The coating exhibits outstanding corrosion resistance both before and after damage.