Spectroscopic studies on Na2O–SiO2 glasses with different Ag concentration using silica obtained from wastes of a geothermal plant

Vitrified galvanic waste chemical stability

“…These results were interpreted from the literature. [16][17][18] The vibration modes found are similar to usual silica glasses, those are, 1200 cm The near 500 cm −1 peaks absence indicates that metallic oxides are not segregated. These results possibly indicate that the metallic oxides will be completely linked with the silicate structure.…”

Biocide glass based on Nb2O5-SiO-CaO-Na2O system

“…Fig. 2 presents FTIR spectra for T15CNb and T20CNb allowing to identify chemical species and, mostly, functional groups as result of interaction between relative energy and the infrared beam over them [13][14][15].…”

Formation of Ag‐Cu nanoparticles in SiO2 films by sol‐gel process and their effect on the film properties

“…Two solutions were prepared in parallel: (a) 5 ml of silver nitrate 10 M, 18.3 ml of TEOS, 13.2 ml of water, 0.1 ml of nitric acid; (b) 5 ml of cupric nitrate 10 M, 18.3 ml of TEOS, 13.2 ml of water, 0.1 ml of nitric acid. These solutions were mixed together 2 h after preparation and allowed to hydrolyze for 1 h. The sol-gel films on glass and Silicon (100) substrates were obtained from this solution by dip coating with withdrawing velocity of 10 mm/s and allowed to dry at 100 °C for 2 h. After that the samples were annealed at 500 °C either in atmospheric air conditions during 4 h or in reducing atmosphere (90N 2 :10H 2 ), also during 4 h. The films obtained by this technique were 200 -300 nm thick [6,7], and slightly colored due to the light absorption and scattering by silver aggregates. The sol-gel powdered samples were obtained keeping the starting solution in an open container at ambient conditions for 5 days until gelation and drying were completed.…”

“…The porosity of gel coatings makes them suitable for gas sensing where the high specific surface area is an important feature. Photochromic coatings including silver halide microcrystals have been formed via the sol-gel process, where the coated glass became photosensitive after Ag microcrystals precipitation at 300 °C [6,7]. It was also found [8] that the presence of Ag particles induces SiO 2 matrix to crystallize in a cristobalite form at 500 °C, although usually the temperature required is 1400 °C.…”