Water diffusion into silica glass at a low temperature under high water vapor pressure

Stress-enhanced ion diffusion at the vicinity of a crack tip as evidenced by atomic force microscopy in silicate glasses

“…Na ¼ 10 nm 2 =s and D water ¼ 0:01 nm 2 =s at 90 C: The high value of ratio between D þ Na and D water was confirmed by more recent experiments [64][65][66]. Gehrke's work gave [49]: D þ Na = 0.29 nm 2 /s for soda-lime glass rods of similar composition corroded in distilled water at 23°C.…”

Reactivity of SiCl and SiF groups in SiO2 glass with mobile interstitial O2 and H2O molecules

“…3 shows IR absorption spectra of Cl-and F-doped samples before and after the H 2 O loading. The H 2 O loading incorporated $10 19 -10 20 cm À3 SiOH groups and $10 18 -10 19 cm À3 interstitial H 2 O [17], whose absorption bands are located at $3670 and $3300-3500 cm À1 , respectively [3,4]. No other distinct induced absorption was found in the F-doped sample.…”

“…The Cl-doped sample was annealed for 480 h at 400°C. The F-doped sample was treated for 3720 h at lower temperature, 170°C, to increase the fraction of interstitial H 2 O with respect to that of SiOH groups by suppressing the hydrolysis of glass network [2][3][4]. The samples were characterized by visible-ultraviolet (VIS-UV), Fourier-transform (FT) IR and FT-Raman spectrometers (Hitachi U-4000, Perkin Elmer Spectrum One and Nicolet Model 960, respectively).…”

Glass Fibre Strength—A Review with Relation to Composite Recycling

“…It is noteworthy that this reaction breaks structural bonds, which must have consequences on the response of the glass structure to applied stress. At high enough temperatures, the reaction is fast, and reaction equilibrium is established with an equilibrium constant [88]. The concentration of dissolved molecular water, [H 2 O], in the glass is proportional to atmospheric water vapour pressure.…”

“…Interestingly, this would imply that exposure of glass to elevated temperatures could presumably lower the water content and increase the measured modulus (as has been experimentally observed by Yang and Thomason [54]). It has been suggested that water enters into glasses, accelerated by tensile stress and causes swelling, which reduces modulus and strength in a manner similar to the plasticization effect in polymers [88,89]. Furthermore, the magnitude of K has been shown to increase in the temperature range 200-550˝C in silica glass [91], implying the likelihood of increasing Si-O-Si structural bond breakage with increasing conditioning temperature in the temperature range, which causes significant strength loss in GF.…”