Synthesis and spectroscopic characterization of coumarin 440 dye doped silica gel rods

We have studied silica gel by sol–gel technique for the preparation of new dye-laser materials. Silica gel rods with dimension 50 × 10 mm2 have been prepared successfully without breaking. It shows high transparency and good mechanical strength. Tetraethylorthosilicate (TEOS), formamide in molar ratio (0.25:0.70), 80 ml ethanol, 20 ml dimethylformamide (DMF), 10 ml water, hydrochloric acid as a catalyst (at pH 6), and 0.5 ml silicone defoaming agent/surfactant have been used. The synthesis has been carried out in a beaker and the reaction mixture is caste in to the flat bottom glass tubes at 40 °C after thoroughly mixing of all the ingredients. These complex reactions, that carried out by hydrolysis and condensation in the silica gel formation show less gel time ∼8–10 h at 40 °C. Coumarin. 440 dye was doped during the preparation of all the ingredients solution mixture. It has been observed that that the compatibility of Nile blue dyes with silica-gel promise good homogeneity with transparency.In the present study, synthesis, dye doping, FTIR, UV–vis/NIR, and fluorescence have been studied. We have observed that coumarin doped silica gel rods give good fluorescence showing sharp peaks in the visible range. UV–vis spectra of prepared silica gel also indicate the absorption in visible range. Thermal stability of rods were studied by DSC/TGA methods. Eventually it is found that these dye doped silica gel materials explore the possibility for new solid-state dye laser materials.