Sodium trisilicate

Figure 7. EE and PIE accompanying the fracture of sodium trisilicate glass in three point bend. Fracture occurred at time t = 0. Both emissions show evidence of detector saturation at fracture. (Reproduced with permission from Ref. 13. Copyright 1988 American Vacuum Society.)...

The Ti 2p doublet appears on the extreme left side of Fig. 1. Ti02 was added to the glass because it is present in nuclear waste and also because it is useful as an internal reference for binding energy determinations ( 1 ). The sodium trisilicate glasses with various additive oxides, listed in Table I, were studied by XPS. 

Secondary relaxation in sodium trisilicate glass has been observed in the measurements of electrical modulus (M ) and shear modulus (G ) as shown in Figure 9.02. It can be seen from the figure that behaviours of... 

Figure 9.02 Shear modulus and electrical modulus for sodium trisilicate glass. Note the relaxation step in G around 0 C and that of M at 0.4 Hz at 0 C (After Angell, 1988).

Describe the effect of quenching versus annealing on each of the following properties of a sodium trisilicate glass. 

A sodium trisilicate glass contains 0.1 mol% Cr03. The glass is heat treated in 400 torr of hydrogen gas, which reduces the ions to Cr ions. The density of the glass is 2.5 gm cm", the hydrogen permeability at the treatment temperature is 2 x 10 molecules s cm" atm. How thick is the reduced layer after 10 hours of treatment After 50 hours If the sample is 5 mm thick, what % of the Cr " has been reduced to Cr after 20 hours ... 

Explain the process of dissolution of a sodium trisilicate glass in water. Explain the effect of pH on the process. Explain why a sodium alumino-silicate glass is more durable than a sodium silicate glass in water, but is less durable in a strong acid. 

Figure 18. Heavy line density profile of Ne atoms that were placed as a gas phase above a sodium trisilicate glass surface (ORIGINAL) and allowed to adsorb at 77 K. Light line same glass, but Na ions removed from the glass surface (Na depleted), showing greater penetration when Na ions removed. See text for details. Glass smface located at 0, bulk to left (-10 direction), gas phase to right.

Her RK (1979) The chemistry of silica. John Wiley and Sons, New York Isard JO (1959) Electrical conductivity in aluminosilicate glasses. J Soc Glass Technol 43 113-123 Kamitsos El, Kapoutsis JA, Jain H, Hsieh CH (1994) Vibrational study of the role of trivalent ions in sodium trisilicate glass. J Non Cryst Sol 171 31-45... 

The fabrication scheme for core-shell nanoparticles was adapted from work done by Lee and Meisel and Ung et al." Silver nitrate (99.998%), hydrogen tetrachloro-aurate(III) (99.999%), sodium citrate dihydrate (99+%), (3-aminopropyl)trimethoxysilane (97%), and sodium trisilicate solution (27%) were used. Absolute ethanol was used for quenching the Si02 shell growth. In all cases, the metallic core of the core-shell nanoparticle was synthesized before growing the dielectric shell. 

---