Inorganic Silicon Compounds

The most important industrially utilized silicon compounds include chlorosilanes, methylchlorosilanes, silicones, silicon dioxide and silicic acids in different forms, silicates in the form of glass, water glass, enamel frits, silicate fillers, zeolites, silicon carbide and silicon nitride. 

This section will be confined to chlorosilanes and silicic acid esters. The other compounds will be dealt with, in accordance with their application sector, in other sections of this book. 

Silicates and Silicate Products Silicate products are utilized in a multiplicity of applications. They are dealt with under the following product groups  

Silicon dioxide and Silicic acids Manufacture and applications in the filler sector, see Sections 5.8.3.1 and 5.8.4.I. 

Silicon carbide Manufacture and applications in the nonoxide ceramics sector, see Section 5.5.5.4. 

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Mai, C. and Militz, H. (2004a). Modification of wood with silicon compounds. Inorganic silicon compounds and sol-gel systems a review. Wood Science and Technology, 37(5), 339-348. 

Silicon is next to oxygen the most abundant element in the lithosphere the average content amounts about 30% by weight. Inorganic silicon compounds such as silica and silicates form the basis of most of the rocks forming the earth s crust. In the atmosphere, there is no silicon present, except as dust of cosmic and terrestrial origin. The silicon content in the hydrosphere, mainly in form of dissolved silica (silicic acid), is also very small. 

Because of its use in semiconductors, silicon has emerged as a key element in modem technology. Concurrent with this phenomenon has been an awareness of the toxicity of silicon compounds, many of which, fortunately, have relatively low toxicities. This section covers the toxicological aspects of inorganic silicon compounds. 

Silicon halides (especially the readily available chlorides) are probably the most synthetically useful and versatile monomeric inorganic silicon compounds. They may readily be reduced to hydrides, hydrolyzed to silanols (and subsequently to siloxanes), treated with other protic species such as alcohols, carboxylic acids, amines, and thiols to give SiA)R, Si-0C(0)R, Si NR2, and Si SR species respectively, used to make sUyl pseudohalogen derivatives by treatment with silver or alkali metal salts, for example, treated with sodium... 

This chapter reviews various theoretical aspects of silicon chemistry. The emphasis will be on organosilicon compounds but formal inorganic compounds of silicon such as H2Si=SiH2, H2Si , H3SiNH2, polysilanes, etc., which are closely related to the theme of this book and which we consider to be of interest to the potential reader, will also be discussed. However, we have omitted from the discussion (or mention only briefly) purely inorganic silicon compounds such as silicates. 

Atomic absorption spectrometry (AAS), atomic emission spectrometry (AES) [11], infrared (IR), Fourier transform infrared (FTIR) and Raman spectroscopy have all been studied at various times for the determination of silicon compounds. AAS has been used to determine silicon in methylisobutylketone, chloroform or petroleum ether extracts of packaging materials and foodstuffs [12-17]. However, these methods suffer from the disadvantage that they do not distinguish between organic and inorganic silicon compounds, similarly inductively coupled plasma AES measures total silicon [11]. 

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