Tailoring $$\hbox {LaB}_{\mathrm {6}}$$ nanoparticle-based self-healing film for heat-shielding window

Abstract

Effective insulation of near-infrared (NIR) from solar energy via the use of transparent coating on the windows is one of the most essential issues in energy savings. In this work, a novel lanthanum hexaboride ( $$\hbox {LaB}_{\mathrm {6}}$$ )/poly(methacrylate-2-ureido-4[1H]-pyrimidinone) functionalized poly(n-butyl acrylate) ( $$\hbox {PnBA-}r\hbox {-PMAUPy}$$ ) film was prepared via an in-situ radical polymerization method to achieve heat insulation and self-healing performance. $$\hbox {LaB}_{\mathrm {6}}$$ nanoparticles synthesized by a low-temperature method were employed as a NIR shielding material, while $$\hbox {PnBA-}r\hbox {-PMAUPy}$$ was utilized as a material to enhance the reliability of long-term service. Benefitting from hydrogen bonding interaction, the film showed a marked progress in self-healing property at ambient temperature. As displayed by optical absorption results, the increase of $$\hbox {LaB}_{\mathrm {6}}$$ content can effectively enhance the NIR shielding ability. The NIR blocking ratio of the thermal barrier film with a thickness of 0.64 mm can reach 97.5%, and the self-healing rate is about 84% for 20 mg $$\hbox {LaB}_{\mathrm {6}}$$ , respectively. The self-healing film for heat-shielding window can be a promising candidate with long-term service.