Liquid-like PDMS brushes/TiO₂ microcapsule-driven coatings with integrated self-healing, photodegradation, and antifouling functions

This study reports a novel core-shell structured microcapsule system, in which 2-hydroxyethyl methacrylate is used as the core material and Ethyl cellulose (EC) as the shell. Titanium dioxide (TiO₂) nanoparticles were electrostatically assembled onto the microcapsule surface and subsequently grafted with polydimethylsiloxane (PDMS) under UV irradiation, forming PDMS-functionalized TiO₂-ethyl cellulose microcapsules (PDMS-TECM). These microcapsules were uniformly embedded within an epoxy matrix to construct a robust and intelligent coating. The incorporation of TiO₂ significantly enhanced the thermal stability, mechanical strength, and UV-induced thermal effects of the coating, enabling rapid crack closure under UV exposure. Simultaneously, the photocatalytic activity of TiO₂ enabled the degradation of organic pollutants, while the grafted PDMS chains imparted surface hydrophobicity and antifouling properties. The synergistic integration of UV-induced thermal self-healing, photocatalytic cleaning, and hydrophobic surface functionality provides a multifunctional strategy for the development of next-generation self-sustaining coatings suitable for harsh environments.