In-situ high temperature Raman and Brillouin light scattering studies of sodium silicate glasses

Understanding Sodium Borate Glasses and Melts from Their Elastic Response to Temperature

“…, and the increased network connectivity due to the conversion of threefold boron into fourfold or due to the increased concentration of IRO units after annealing . Variations of elastic moduli with composition in sodium borate glasses are distinctly different from those in sodium silicate glasses where the moduli decrease with the initial increase in Na 2 O content . This is because the addition of Na 2 O to SiO 2 causes a breakdown of the network structure, whereas the initial addition of Na 2 O to B 2 O 3 increases the coordination number of boron and promotes the glass network connectivity…”

“…d, this initial decrease in the Poisson's ratio with Na 2 O content agrees with the increase in the network connectivity/dimensionality due to the increase in fourfold‐coordinated boron . Once nonbridging oxygens (NBOs) start to form above 30% Na 2 O, the Poisson's ratio increases with the Na 2 O content, similar to that observed in sodium silicate glasses . But in annealed glasses, the trend in the Poisson's ratio is a little more complicated where it first increases, then decreases and then increases with increasing Na 2 O content in the composition range studied here.…”

In-situ Raman and Brillouin light scattering study of the international simple glass in response to temperature and pressure

“…These behaviors are between those of abnormal glasses, such as silica glass, whose elastic moduli increase with temperature, and normal glasses, such as window glass [29], whose elastic moduli decrease with temperature. The nearly temperature-independent elastic moduli in the ISG were also previously observed in binary sodium silicate glasses with Na 2 O content between 15-20 mol% [32]. The minimal changes in the elastic moduli within this temperature range reflect the structural integrity of the ISG.…”

Influence of drying temperature and atmosphere on the mechanical strength of iron‐ore agglomerates and sodium silicates for application in sintering processes

“…[18,19] Hematite has a weak band at 1046 cm À1 , which coincides with the Si-O-Si stretching vibrations of sodium silicate at 1060 cm À1 and with the strong band of symmetric stretching present in CO 3 À2 . [20][21][22] The Raman spectra of samples of pure sodium silicate and a mixture of NaOH and iron ore fines are shown in Figure 4. Both samples were dried at 250 8C in a pure CO 2 atmosphere.…”