Physical, silicate glasses

The physical and chemical properties of silicate glasses depend on the composition of the material, ion size, and cation coordination number (9). A melt or glass having a Si02/Na20 ratio of 1, ie, sodium metasiUcate [1344-09-8] is expected to possess a high proportion of (SiO ) chains. At a ratio of 2, sheets might predominate. However, litde direct evidence has been shown for a clear predominance of any of these stmctures. The potential stmctures of sihcate melts of different ratios are discussed in detail elsewhere (10—12). 

Silicon shows a rich variety of chemical properties and it lies at the heart of much modern technology/ Indeed, it ranges from such bulk commodities as concrete, clays and ceramics, through more chemically modified systems such as soluble silicates, glasses and glazes to the recent industries based on silicone polymers and solid-state electronics devices. The refined technology of ultrapure silicon itself is perhaps the most elegant example of the close relation between chemistry and solid-state physics and has led to numerous developments such as the transistor, printed circuits and microelectronics (p. 332). 

Physical properties, silicate glasses. 152-54 Phytoplankton, impact of Pu waste. 275-92... 

Silicate glasses, physical properties, 150-54 Single-phase reactions, ground-water 335-44 Site, ground-water leaching,... 

Rabinovich, E. M. (1983). On the structural role of fluorine in silicate glasses. Journal of Physical Chemistry, 24, 54-6. 

Huang, C. and Cormack, A.N. (1990). The structure of sodium silicate glass. Journal of Chemical Physics 93 8180-8186. 

Pollard, A.M., Matthew, J.A.D. and Heavens, O.S. (1980). Electron loss spectra of silicate glasses. Physics and Chemistry of Glasses 21 167-170. 

Fig. 5. Plot of logm B and Na normalized release rates vs. the activity of silicic acid for both phase-separated and physically homogeneous glass specimens. All rates were plotted at steady-state conditions. MAGNOX and HLP-31 represent phase-separated whereas LAWA33 and HLP-9 represent homogeneous glass specimens. The behaviour of homogeneous glass includes an inverse relationship between rates and silicic acid activity and a difference between B and Na rates as silicic acid activity increase. The magnitude of the difference between B and Na rates is related the amount of excess Na (see Fig. 3). Relatively faster element release rates ( lOx), identical release rales of Na and B, and independence from activity of silicic acid appears to characterize phase-separated glass.

Dran, J.-C., Della Mea, G., Paccagnella, A., Petit, J.-C. Trotignon, L. 1988. The aqueous dissolution of alkali silicate glasses Reappraisal of mechanisms by H and Na depth profiling with high energy ion beams. Physics and Chemistry of Glasses, 29, 249-255. 

Figure 1 The atomic scale structure of the potassium silicate glass containing 20 mol % K20 (Reproduced with permission from reference 17. Copyright 1991 American Institute of Physics.)...

Sviridov SI, Eliseeva NP. Field-assisted diffusion of potassium ions in sodium silicate glass. Glass Physics and Chemistry. 2006 32(6) 604-ll. DOI 10.1134/... 

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