Tetraethylorthosilicate tetraethoxysilane

Thermal decomposition of two starting materials in inert organic solvent may provide a convenient route for the synthesis of mixed oxides or precursor of mixed oxides. For example, when a mixture of aluminum isopropoxide and tetraethoxysilane (tetraethylorthosilicate) in a 3 1 ratio is decomposed in toluene, an amorphous product is obtained." Note that thermal decomposition of the former compound alone yields %-alumina, while the latter compound alone does not decompose at the reaction temperature." Mullite is crystallized by calcination of the product at 900°C." It is known that the crystallization behavior of mullite from the precursor gel depends on the homogeneity of mixing of aluminum and silicon atoms in the precursor when the precursor gel has atomic scale homogeneity, mullite is crystallized at 900°C, and the gel with homogeneity in a nano... 

The first CVD process to be introduced into semiconductor technology in 1961 was that involving the pyrolysis of tetraethoxysilane, Si(OEt)4 (commonly called TEOS from tetraethylorthosilicate) [31]. Since that time, a vast literature has been developed on silica-CVD from TEOS and a number of reviews published [32, 33]. Deposition occurs at an optimum temperature around 750°C. However, under LPCVD conditions, the growth temperature can be significantly lowered (> 600°C). 

The first method uses the controlled concurrent hydrolysis of tetraethoxytitanium (IV) and tetraethoxysilane. This procedure has been labeled the mixed alkoxide method. Frequently, the acronyms TET (tetraethyltitanate) and TEOS (tetraethyl orthosilicate or tetraethoxysilane) are used for the respective reactants these are derived from the alternative names tetraethyl titanate and tetraethylorthosilicate. In examples described in patents, the synthesis involves adding TET to TEOS and then combining the alkoxide mixture with an aqueous solution of a SDA, which is typically tetrapropylammonium hydroxide (TPAOH). The resulting precursor mixture is then heated to a temperature of 175 °C to initiate crystallization. Subsequent washing of the crystallized solid with water, drying, and air calcination produces framework titanium-containing silicalite. 

Chemistry. In the most important example, hydrolysis of an alkoxysilane such as tetraethoxysilane or tetraethylorthosilicate (TEOS),... 

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