Photoactive barium titanate-encapsulated polymer microcapsules for infrared-reflective coatings

Abstract

Energy-efficient surface applications require infrared (IR)-reflective coatings with strong adhesion and effective thermal management. In this study, polymer microcapsules encapsulating surface-modified barium titanate (BaTiO 3 ) particles were prepared by suspension polymerization. The BaTiO 3 particles were modified with oleic acid (o-BaTiO 3 ) to improve their dispersion in the monomer phase before encapsulation into poly(methyl methacrylate-ethyleneglycol dimethacrylate-benzophenone) (P(MMA-EGDMA-BP)) microcapsules. The BP component was incorporated into the microcapsule shell as a photoactive component to promote UV-assisted coating retention on substrate surfaces. The resulting microcapsules exhibited a coating add-on exceeding 90%, with approximately 98% of the coating remaining after post-treatment and washing. In addition, the BaTiO 3 -containing microcapsules exhibited an average IR reflectance of over 70% and reduced the surface temperature by up to 13 °C under laboratory thermal radiation. These results demonstrate that integrating BaTiO 3 encapsulation with BP-containing polymer microcapsules provides an effective approach for improving coating retention and IR-reflective performance, offering potential for thermal management coating applications.