In Situ Incorporation of Hydrophobic Emissive Complexes in Monodisperse Copolymer Particles via Surfactant-free Emulsion Polymerization

Abstract

Iridium complex-incorporated monodisperse particles are prepared via surfactant-free emulsion polymerization. For this process, a vinyl-substituted iridium complex (IrV) is synthesized and copolymerized with 4-vinylpyridine (4VP) and methyl methacrylate in an aqueous phase. Toluene is then used as a cargo solvent to transfer the IrV through the aqueous phase in the form of minidroplets. The amphiphilicity of 4VP enhances the transfer efficiency and prevents self-quenching of the copolymerized iridium complexes. The iridium complexes copolymerized in the particles show good photostability for more than 6 months and ∼3.6 times the enhanced photoluminescence quantum yield because of the scattering-induced light extraction effect of the particles. Moreover, phosphorescent three-dimensional photonic crystals (3D PCs) with different photonic band gaps are fabricated by adjusting the size of the emissive monodisperse particles. The phosphorescence of the 3D PC is tuned according to the position of the photonic band gap to reduce the full width at half-maximum by ∼24 nm. © 2020 American Chemical Society.