Multicomponent silicates

Multicomponent Silicate Systems. Most commercial glasses fall into the category of sihcates containing modifiers and intermediates. Addition of a modifier such as sodium oxide, Na20, to the siUca network alters the stmcture by cleaving the Si—O—Si bonds to form Si—0-Na linkages (see Fig. 3c). 

Pereira, A.P.V., Vasconcelos, W.L and Orefice, R.K. (2000) Novel multicomponent silicate-poly(vinyl alcohol) hybrids with controlled... 

Dilmore, M.F. (1977). Chemical Durability of Multicomponent Silicate Glasses. 

Ghiorso M.S. (1987a) Chemical mass transfer in magmatic processes, III crystal growth, chemical diffusion and thermal diffusion in multicomponent silicate melts. Contrib. Mineral. Petrol. 96, 291-313. 

Van Der Laan S.R., Zhang Y., Kennedy A., and Wylie P.J. (1994) Comparison of element and isotope diffusion of K and Ca in multicomponent silicate melts. Earth Planet. Sci. Lett. 123, 155-166. 

Si02, 18 B2O2, 7 AI2O2, 3 BaO, 6 Na20 Multicomponent silicates TEOS, B(0CH3)3, M(OCpp... 

Pelton, A. D. Blander, M. Computer Assisted Analysis of the Thermodynamic Properties and Phase Diagrams of Slags in Proc. Second Int l. Symp. on Metallurgical Slags and Fluxes, Fine, H. A. Gaskell, D. R., eds., TMS-AIME, Warrendale PA, 1984, pps 281-294 Blander, M. Pelton, A. D. Analyses and Predictions of the Thermodynamic Properties of Multicomponent Silicates , t6[Pg.193]

Si02, 18 B203, 7 A1203, 3 BaO, 6 Na Multicomponent silicates TEOS, B(OCH3)3, Al(OC4H9)3, Ba(OC2H5)2... 

With multicomponent amorphous polymeric materials, prediction of the occurrence of a surface enrichment effect is very difficult because of many uncertain parameters. With worked multicomponent silicate glasses, the wet grinding and polishing process, and the cleaning with liquids, leaches out the soluble constituents,... 

Figure 12a,b. (top a) Si-O pair distribution functions for four multicomponent silicate glasses (see Table 2 for compositions). First Si-0 peak unaffected by composition, but second Si-O peak changes slightly, with EG3 shghtly shorter distance than other compositions, (bottom b) Al-O pair distribution functions for four multicomponent silicate glasses (see Table 2 for compositions). Shght differences in stracture with composition, especially in the second peak in EG3. 

Almeida R.M., Du X.M., Barbier D., OrignacX. Er +-doped multicomponent silicate glass planar waveguides prepared by sol-gel processing. J. Sol-Gel Sci. Technol. 1999 14 209-216 Almeida R.M., Morais P.J., Marques A.C. Planar waveguides for integrated optics prepared by sol-gel methods. Philos. Mag. B 2002 82 707-719. Available at http //www.tandf.co.uk/ joumals/titles/14786435.htinl... 

Some examples of QSPR results involving NMR computed parameters and structural descriptors obtained by MD obtained for a number of multicomponent silicate... 

Multicomponent Silicates briefly discusses synthetic schemes employed to make multicomponent gels and presents the results of several structural studies that examine polymer growth in binary silicate systems. 

It is certainly beyond the scope of this book to discuss in any detail the solution chemistry pertinent to the large number of multicomponent silicate systems described in the literature. However, it is necessary to address at the minimum the synthetic strategies employed in multicomponent gel synthesis. In aqueous systems coprecipitation is so commonly used that it warrants no further discussion here. In alkoxide systems, there are two general approaches 1) hydrolysis of mixed-alkoxide or metal organic precursors and 2) sequential addition of alkoxides to partially hydrolyzed precursors. 

Numerous multicomponent silicate and some nonsilicate gels have been consolidated to glass as is evident from the extensive list compiled by James in Table 7. It is certainly not the purpose of this chapter to present an account of structural changes that occur for all these systems however, examples of... 

Refractive index versus spinning frequency for spun films prepared from multicomponent silicate precursors aged at 50°C and pH 3 for two weeks prior to deposition. 

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