Stability, UV shielding properties, and light conversion behavior of Eu(BMDM)3@polysiloxane nanoparticles in water and polyurethane films

Bifunctional Eu(BMDM)3@polysiloxane nanoparticles were prepared through reprecipitation–encapsulation methods using 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-1,3-propanedione (BMDM) ligand and octyltrimethoxysilane (OTS) precursor and embedded into waterborne polyurethane (PU) coatings to fabricate transparent optical composite films. The photostability and thermostability of the nanoparticles in water and their ability to block UV and convert light when embedded in PU films were investigated. In comparison with the control Eu(BMDM)3 nanoparticles, the Eu(BMDM)3@polysiloxane nanoparticles, especially those prepared at a Eu(BMDM)3/OTS mole ratio of 1:2, exhibited far superior stability under storage conditions, UV irradiation, and heating. They also showed excellent UV-shielding and highly efficient light conversion properties because of the protective polysiloxane. -- Highlights: ► Eu(BMDM)3@polysiloxane nanoparticles were successfully prepared. ► The nanoparticles show excellent stability to storage, UV light, and heat. ► PU film with 0.3 wt% nanoparticles exhibited excellent UV shielding performance. ► The nanoparticles can be used as bifunctional additives for agriculture film.