Absorption and fluorescence spectra of rhodamine B molecules encapsulated in silica gel networks and their thermal stability

The absorption, fluorescence and fluorescence excitation spectra of rhodamine B molecules encapsulated into −O −Si −O − networks (by the sol–gel processing of a tetraethyl orthosilicate (TEOS) solution containing rhodamine B) were measured and their thermal stability was investigated. The absorption and fluorescence spectra of rhodamine B measured during the sol—gel process are similar to those of rhodamine B adsorbed on porous Vycor glass and dissolved in ethanol solution. These results indicate that the rhodamine B molecules are encapsulated in a stable for in the − O − Si − O − networks of the silica gel during the gelation of the TEOS solution. The thermal stability of the encapsulated rhodamine B molecules is enhanced.