Tailoring LaB$_6$ nanoparticle-based self-healing film for heat-shielding window

摘要

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 (LaB$_6$)/poly(methacrylate-2-ureido-4[1H]-pyrimidinone) functionalized poly($n$-butyl acrylate) (PnBA-$r$-PMAUPy) film was prepared via an in-situ radical polymerization method to achieve heat insulation and self-healing performance. LaB$_6$ nanoparticles synthesized bya low-temperature method were employed as a NIR shielding material, while PnBA-$r$-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 LaB$_6$ 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 LaB$_6$, respectively. The self-healing film forheat-shielding window can be a promising candidate with long-term service.