Development of color-tunable photoluminescent polycarbonate smart window immobilized with silica-coated lanthanide-activated strontium aluminum oxide nanoparticles

Simple inorganic/organic nanocomposite was employed to create afterglow smart window. An organic/inorganic nanocomposite was created by combining recycled polycarbonate plastic (RPC) with silica-coated lanthanideactivated strontium aluminum oxide nanoparticles (LSAO NPs). The LSAO NPs were coated with silica by the heterogeneous precipitation approach to offer LSAO-encapsulated silica nanoparticles (LSAO@SiO2). Transmission electron microscopy (TEM) was employed to study the morphologies of LSAO and LSAO@SiO2 NPs, demonstrating diameters of 4-18 nm and 85-98 nm, respectively. In order to assure the formation of transparent plastic window, phosphorescent strontium aluminate nanoparticles were distributed uniformly throughout the polycarbonate plastic. The color shift features were studied with the use of luminescence spectra and CIE Lab coordinates. Both blank and glowing sheets were transparent in the standard visible light. After being excited at 374 nm, the window sheets emitted at 527 nm. After being exposed to ultraviolet light, the photoluminescent sheets brightened to a vivid green. The photoluminescent window sheets displayed persistent and reversible luminescence. Scanning electron microscope (SEM), X-ray fluorescence (WDXRF) and energy-dispersive X-ray (EDXA) were used to examine the morphology of sheets. The improved ultraviolet protection and superhydrophobic activity were achieved without compromising the film inherent physico-mechanical properties.