Multi-component assembly and photophysical properties of europium polyoxometalates and polymer functionalized (mesoporous) silica through a double functional ionic liquid linker.

ABSTRACT

In this paper, we put forward a strategy to assemble a novel series of multi-component photofunctional hybrid materials (named as Eu-Si-P1(2,3)) centered with europium polyoxometalates (Na9EuW10O36·32H2O, abbreviated as EuW10) and polyester modified silane (P1-Si, P2-Si, P3-Si, P1 = poly glycohol, P2 = bis(2-hydroxyethyl)ether, P3 = 2-hydroxyethyl methacrylate) through an ionic liquid compound (1-methyl-3-(trimethoxysilylpropyl) imidazolium chloride, IM(+)Cl(-)) as the double functional linker. Furthermore, using Pluronic P123 surfactant as a template to control the sol-gel process of organically modified siloxane precursors, Eu-SBA15-P1(2,3) hybrids with mesoporous silica are constructed correspondingly. The results reveal that Eu-Si-P1(2,3) hybrids present the lower red/orange intensity ratio, longer lifetime and higher quantum yield than Eu-SBA15-P1(2,3) hybrids. The luminescent lifetime and quantum efficiency of Eu-Si-P1(2,3) hybrids are comparable with EuW10 compounds in spite of their low concentration of photoactive EuW10, which is important for practical applications. The CIE chromatic coordinates of some systems are close to the cool-white region and can be expected to be utilized as cool white lighting (close to sunlight).