Synthesis and spectroscopic characterization of Nile Blue 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 50mm×10mm have been prepared successfully without breaking. It shows high transparency and good mechanical strength. Tetraethylorthosilicate (TEOS), formamide in molar ratio (0.25:0.70), 80ml ethanol, 20ml dimethylformamide (DMF), 10ml water, hydrochloric acid as a catalyst (at pH 6) and 0.5ml 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 ∼8–10h at 40°C. The doping of dye (Nile Blue 690) has been taken during the preparation of all the ingredients solution mixture. It has been observed that the compatibility of Nile Blue dye with silica-gel promise good homogeneity with transparency. In the present study, synthesis, dye doping, FTIR, UV/vis–NIR and fluorescence spectroscopy have been studied. We have observed that Nile Blue doped silica gel rods material give good fluorescence showing sharp peaks in the visible range. UV–vis spectra of prepared silica gel material also indicate the absorption in visible range. Thermal stability of rods was 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.