Luminescent properties of encapsulation of europium complex into meso-structured silica monoliths

Meso-structured silica monoliths using PEG (PEG=polyethylene glycol) as a low-cost template and synthesized via sol-gel methods were used as host materials for incorporation of europium complexes Eu(BA)3Phen (BA=benzoic acid and Phen=1,10-phenanthroline). The meso-structured silica was silylated by 3-aminopropyltriethoxysilane (APTES) or 3-glycidoxypropyltrimethoxysilane (GPTMS) before wet impregnation. Samples were characterized by BET, diffuse reflectance (DR) spectroscopy, infrared spectroscopy and fluorescence measurements. The results showed that the emission quantum efficiency of GPTMS silylated meso-structured silica with larger pore size was up to 44.6%. Also, the lifetime measurement showed the complex encapsulated in this rigid matrix had longer lifetime than the pure complex in solid or liquid.