Using novel polymer microspheres as an efficient UV filter and blue light converter for constructing multifunctional transparent polyvinyl alcohol films

Overexposure to ultraviolet (UV) light can pose a threat to human health and lead to the photodegradation of organic materials, thereby there is great interest in the development of UV-shielding and UV-to-visible light converting materials. In this study, a novel polymer microsphere with both UV-shielding and blue-light-emitting characteristics was fabricated by grafting disodium 4,4′-bis[(4-anilino-6-hydroxyethylamino-1,3,5-triazin-2-yl) amino] stilbene-2,2′-disulphonate (VBL) onto poly (maleic anhydride-co-α-methyl styrene) (PMAS) microspheres via an esterification reaction. The as-prepared PMAS-VBL microspheres were then incorporated into polyvinyl alcohol (PVA) to prepare composite films . The introduction of PMAS-VBL endowed PVA with excellent UV-shielding and fluorescent properties, which are mainly derived from the UV-to-blue light converting ability of VBL. PVA films containing 7 wt% PMAS-VBL microspheres can block almost 100% UV light while the visible light transmittance was maintained at 66.9% and the absolute quantum yield of the films reached up to 74.26%. This work opens up a new pathway for fabricating UV filters and blue light converters, which are very promising for a diversity of UV-shielding and fluorescence-based applications.