Porous silica as host for PEG-supported coumarin molecules

The design of novel organic–inorganic systems made of poly(ethyleneglycol) (PEG)-supported coumarin loaded into porous silica is presented. The hybrid system was obtained by impregnation of a xerogel silica matrix with a PEG-supported coumarin ethanolic solution. The chemical and physical properties of the hybrid systems are evaluated by means of infrared spectroscopy and thermo-gravimetric analysis, and correlated to UV–Vis optical absorption and time-resolved photoluminescence. It was found that the optical properties of the coumarin, which are not affected by the polymeric PEG support, are preserved upon loading into the silica porous support. The hybrid material obtained may represent a tool for drug delivery as the release of the PEG-supported coumarin from the silica xerogel into water media takes place.