Siliconic acids

When the system is stopped to be loaded with raw stock, it receives air with humidity, which breaks down silicon tetrachloride into hydrogen chloride and gel of silicon acid, as well as self-inflammable silanes. Calcium chloride (the melting point is 772 °C, the boiling point is 1600 °C) remains in the chlorinator and combines with pieces of unreacted ferrosilicon to form cinder, which is accumulated in the furnace and loaded off with graphite. 

No such compound has ever been isolated and identified, however. A single organic group seems to exert insufficient retarding influence on the condensation of the silanetriol, and so it proceeds immediately to split out water and to form polymeric products. At one time it was thought that the condensation produced a siliconic acid analogous to a carboxylic acid ... 

This supposed siliconic acid is a white silicalike solid, however, and obviously is polymeric rather than of the monomeric form shown. 

Siliconic acid. A hypothetical compound of silicon analogous to a car-... 

Apart from the reaction with halogen derivatives, use was also made, for the synthesis of silicon-containing cellulose esters, of the reaction of alcoholysis, with cellulose, of tetraalkoxysilanes or alkyl(aryl)trialkoxy-silanes and the amides of siliconic acids (64) ... 

The consolidation mechanism of SPC compositions containing these additives can be considered as resulting from two processes decompression of silicon acid gel due to a decrease in the surface tension of intermicellar liquid and polymerization under the influence of acid solutions. 

USE Photographic developer. In determination of iron detection and determination of phosphorus and silicon. Acid indicator in bacteriology. 

Gas chromatography with NPD has been applied to the simultaneous analysis of HA and its basic metabolites in biological samples. HA and metabolites are first extracted from the biological material with an ion exchange resin. After elution and lyophUization, the sample is reacted with HFBA, and the derivatives purified on a silicone acid column. Acetylation of the ring NH group, if present, precedes GC analysis. Sensitivity was reported in the picomolar range. 

Germanium/Silicon Acids. Germanium-hydrogen and silicon-hydrogen bonds are quantitatively cleaved with sodium hydride in ethereal solvents (eq 11). ... 

Keywords Silica Clusters / Meta-Silicon Acid / Quantum-Chemical Modeling / Semiempirical AMI and PM3 Approximations / Vibrational Spectroscopy... 

It was postulated that the silicon dioxide molecule is a first intermediate product in the route from silicon tetrachloride to fumed silica. Due to high temperatures in the flame the ortho-silicon acid or meta-silicon acid will not be the main product of silicon tetrachloride hydrolysis or/and oxidation. The silicon dioxide molecule is well known to be stable at high temperatures or in a matrix-isolated state. Therefore, we are able to use silicon dioxide molecules as initial silicon-containing substances to simulate silica particle formation. Meta-silicon acids are able to react with other meta-silicon acid molecules and produce bigger clusters. Three meta-silicon acid molecules form cyclic clusters with four-coordinated silicon atoms and two-coordinated oxygens (Fig. 1). At high temperatures this cluster may loose some water molecules from hydroxyl groups and... 

Figure 18. C li XPS spectra of thin films (ca. 2 nm) of PMMA on oxidized substrates of increasing basic character (a) silicon (acidic), (b) aluminum (weakly basic), (c) nickel (strongly basic). (From Ref. 124.) The numbers of the components in (a) refer to the schematic of Fig. 19. Additional components in (b) and (c) are related to the specific interactions shown in Fig. 19. 

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