Characterization of the Microenvironments of PRODAN Entrapped in Tetraethyl Orthosilicate Derived Glasses

6-Propionyl-2-(dimethylamino)naphthalene (PRODAN) has been widely used to probe the internal environment of sol−gel derived glasses. It is generally assumed that the entrapped probe reports primarily on the internal solvent environment, through changes in emission wavelength, lifetime, or anisotropy. However, we show that other effects, such as aggregation of the probe and adsorption of the probe onto the silica surface, can also alter the …