Cool-white light emitting hybrid materials of a resin–mesoporous silica composite matrix encapsulating europium polyoxometalates through an ionic liquid linker

Abstract

Benzoate (4-hydroxybenzoate, 4-mercaptobenzoate and 4-aminobenzoate) functionalized polymer resin (Merrifield resin (MR) or Wang resin (WR)) and mesoporous silica SBA-15 are connected to assemble photofunctional hybrids by bridging lanthanide ions (Gd³⁺, Eu³⁺) through coordination bonds. The organically functionalized mesoporous SBA-15 are synthesized by co-condensation of tetraethoxysilane (TEOS) and modified by organic coupling agent 3-methacryloxypropyltrimethoxy-silane (denoted as MPTMS) in the presence of Pluronic P123 surfactant as a template. Europium polyoxometalates (Na₉EuW₁₀O₃₆·32H₂O, abbreviated as Na₉EuW10) are encapsulated into the composite host through an ionic liquid (1-methyl-3-(trimethoxysilylpropyl) imidazolium) as a double linker, which is fixed on the surface of mesoporous SBA-15. The detailed physical characterization of these photofunctional hybrids are characterized by Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Thermo-gravimetric Analysis (TGA), Transmission Electron Micrographs (TEM), N₂ absorption and desorption and luminescent performance. It is worth pointing out that some hybrids possess high luminescent output (quantum yields) and long decay time (reaching the millisecond scale) and cool-white light (from CIE diagrams). The research provides a strategy to assemble multi-component hybrids to realize the cool-white integration.