Silicon hydroxides

In this paper detailed methods for the determination of placement and assay of silicon hydride (Si-H), silicon hydroxide (Si-OH) and silicon phenyl (Si-0) functional groups in molecular weight components of silicones of the Sylgard (Dow-Corning Co.) type will be described. The methods are illustrated with the analysis of Sylgard addition prepolymers and of model polydimethylsiloxanes (PDMS). 

Coprecipitation of titanium and silicon hydroxides from their precursors, possibly by sol-gel techniques. 

Hydrolysis in the silicones is usually just a special case of the reaction with organic halides. The most important reaction is the preparation of siloxanes by the hydrolysis of chlorosilanes and the subsequent condensation to form the commercially important polysiloxanes (see Chap. 15). Diethyl silane diol, (CjHs)2Si(OH)s, and the corresponding di-n-propyl and di-n-butyl diols have been made by hydrolyzing the dichlorosilanes. The trimethyl and triethyl silicon hydroxides have been prepared by the hydrolysis of complex organic silicon compounds containing the aceto and the amino group, respectively. ... 

Silicon hydroxide. See Silica, hydrated Silicon monocarbide. See Silicon carbide Silicon powder, amorphous. See Silicon Siloxane. See Polysiloxane Silicone Siloxane, dimethyl-. See Dimethylsiloxane Siloxane emulsion. See Silicone emulsion Siloxanes. See Silicone... 

Silica acid Silic acid (polyortho) Silica hydrate Silica, precipitated Silicic acid Silicic acid hydrate Silicic acid hydrated Silicon hydroxide... 

FIGURE 8.1 Basic steps of a typical sol-gel process from a metal alkoxide. Hydrolysis of aUcylorthosilicates affords silicon hydroxides that undergo condensation reactions to form a silicate network (reproduced from [76] with permission from Wiley). 

The volatility rate of silica, k, is shown by Opila and Hann (1997) in furnace studies, and Robinson and Smialek (1999) in burner rig studies, to be controlled by transport of the volatile silicon hydroxide species through a gaseous laminar boundary layer. Eq. (7-6) gives the following expression for the volatility rate, fc, ... 

Hydrated dihydrogen aluminium triphosphate (AlH2P30io 2H20) is an acid with a dissociation constant, pKa, of approximately 1.5 to 1.6. Its acidity per unit mass is approximately 10 to 100 times higher than other similar acids, such as aluminium and silicon hydroxides. 

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