Silicates preparation

Fig. 72. Relation between composition and specific refraction of a large number of sodium silicates (prepared by different authors).

Figure 8 shows infrared (IR) spectra of the various gels obtained by drying at 100°. Gel of nickel silicate prepared by the SHOP method gave quite different IR spectra profiles from that of either the dried nickel hydroxide or the silica gel, thus supporting the conclusion obtained from the DTA data. 

Fio. 8. Infrared spectra of dried gels a, for nickel hydroxide b, for silica hydrogel c and d, for nickel silicates prepared by the SHOP method at final pH s of 6.6 and 8.4, respectively. 

Nickel silicate prepared by the SHOP method has little activity for hydrogenation in general, but exhibits a high selective activity for the hydrogenation of the benzene nucleus when heated above 500° for 1 hour in hydrogen. It is noticeable that this catalyst has no ability to hydrosplit the C—C bond. 

Cat. 2 Cu-silicate MFI-type Cu-silicate prepared by the rapid crystallization method. The Cu content was 0.57 wt%. 

Okada, Y (1994) Characterization of C-S-H from high reactive -dicalcium silicate prepared from hillebrandite. Journal of the American Ceramic Society 77,1313-1318. 

Alkaline chemicals, e.g. 50% sodium hydroxide, sodium silicate, preparations of alumina and plating solutions (where the soluble silica in diatomite and perlite makes them unsuitable)... 

FIGURE 19 SEM image of intact (A) and broken (B) hollow spheroids of synthetic Mg-phyllo(hexadecyl)silicate prepared by microemulsion methods. Scale bar represents 20 microns. (From Ref. 228.)... 

Comparable behavior was found for a potassium silicate prepared either from Si02 dispersions in KOH or from potassium water glass solutions [95], This silicate is related to magadiite but differs by the reversible transition between hydration states with basal spacings of 1.51 nm and 1.73 nm. (Sodium magadiite does not expand above 1.56 nm.) The air-dried acid with a basal spacing of 1.34 nm rehydrates to —1.5 nm, in contrast to the H+ form of magadiite, which remains at 1.32 nm. The structural difference between these crystalline silicic acids is also evident in enhanced intercalation behavior the acid form of the... 

The composite isotherm for propanol (l)/water (2) is S-shaped with an azeotropic point at Xi = 0.35 (Fig. 25b), which indicates that both compounds, propanol and water, are adsorbed. As in the case of methanol and ethanol, propanol was enriched at the external surface in amounts corresponding to two laya-s. The molar ratio of propanol/water depends on the conditions of parent potassium silicate preparation. For 0.1 < Xi < 0.8, i.e., for the linear section of the isotherm, it varies between 1.4/4.1 and 1.25/2.6 for acids prepared from two different samples of K2Si2o04i VH2O [159]. This is again indicative of the influence of preparation conditions on the stracture (fine structure of the layers, hydrogenbonding system) of alkali silicates and their corresponding crystalline silicic acids. 

Oh E., Chakrabarti K., Jung H., Whang C. Microstructures and mechanical properties of organically modified silicate prepared under various process conditions. Mater. Sd. Eng. 2002 B90 60-66 Pope E.J.A., Asami M., Mackenzie J.D. Transparent silica gel-PMMA composites. J. Mater. Res. 

Ravaine, D., A. Seminet, and Y. CharboniUit, 1986. A new family of organically modified silicates prepared from geh. J Non-Cryst Solids 82 210-19. 

Figure 3. XRD and MAS NMR data for a gallium-aluminium silicate prepared by sol-gel synthesis,...

Apatite-Type Lanthanum Silicates Prepared via Mechanochemical... 

Table 4. Structural parameters of Fe-doped apatite-type lanthanum silicate prepared via MA of Si02-La203-Fe203 followed by annealing at 1200°C.

In the cement industry, the main components of this type of reaction are calcium silicates prepared by the action of silica on calcium carbonate (calcareous) according... 

RAVAiNE D, SEMiNEL A, CHARBOUiLLOT Y and viNCENS M, A uew family of Organically modified silicates prepared from gels , J Non-Cryst Solids, 1986, 82, 210-219... 

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