Hydroxyapatite nanoparticles as novel low-refractive index additives for the long-term UV-photoprotection of transparent composite materials

Abstract

Hydroxyapatite (HA) nanoparticles are introduced as a novel type of low-refractive-index additives for the formation of transparent polymer powder coatings. The beneficial effects of nano-HA for the long-term UV-photoprotection of polyester composite materials under accelerated weathering conditions are demonstrated in this work. These results are of considerable interest for the development of new hybrid organic–inorganic systems to be used as coating materials for outdoor applications such as transparent UV-resistant protection layers stabilized with functional nanoparticles based on cheap and biocompatible compounds.