Structural evolution of sol–gel SiO2 heated glasses containing silver particles

White luminescence from sol–gel silica doped with silver

“…Of interest is that the addition of 1 mol% Ag did not change the phase of the amorphous structure of silica, even after annealed at 1000°C. This is contrary to previous reports which suggested that the addition of Ag to amorphous SiO 2 promoted partial crystallization of the cristobalite phase [17,18].…”

Characterization of alkali silica reaction gels using Raman spectroscopy

“…There is the possibility that the bands of Q 2 units may have some contribution from a peak linked to Si\ \OH stretching mode of silanol groups at 970 cm −1 [29,36,39]. An attempt was made to use FTIR to verify the existence of silanol in the synthetic gels by confirming the presence of the 950 cm − 1 band which are linked to the stretching of this group [42]. However, it was found that this band of interest was most probably obscured by the broad band between 800 and 1200 cm −1 attributed, among others, to the out of plane bending of carbonate groups, Si\ \O\ \Si asymmetric stretching band and vibrations of tetrahedral SiO 4 groups [43,44].…”

Study of structural short order and surface changes of SiO2 compounds

“…This pronounced shift may be connected to the structural order change of SiO 2 [13]. change of Si-O-Si is provided by the band at 800cm 1 (Figure5).…”

“…The mean peak is associated with the stretching vibration of Si-O-Si [11-12 different bending vibrations attributed to Si are indicated in the figure. The bands located at 555 cm and 950 cm -1 are associated with Si-O bending vibrations of no bridging Si-OH bonds and stretching vibration respectively Si [13][14][15].…”

“…The mean peak is associated with the 12]. In addition, different bending vibrations attributed to Si-O-Si [13][14][15] are indicated in the figure. The bands located at 555 cm -1 O bending vibrations OH bonds and stretching vibration In addition, we can notice that the mean band of SiO2-1 spectra after reaction with and without the presence of 1 before reaction as This pronounced shift may be connected to the ].…”