Tetraethoxysilane derivatives

Patel, A.K. Sharma, P.S. Prasad, B.B. (2009). Electrochemical sensor for uric acid based on a molecularly imprinted polymer brush grafted to tetraethoxysilane derived sol-gel thin film graphite electrode. Materials Science and Engineering C, 29,1545-1553. 

It was shown in (14) that tetraethoxysilane derivatives can be used as building blocks in the buildup of a hyperbranched structure successive steps in the synthesis of such a polymer have been discussed in (19). The main steps of this process are shown in Scheme 1. It was also discussed that scheme 1 illustrate an idealized development of... 

Orthosilicates are derivatives of orthosilicic acid Si(OH)4. The most common is tetraethyl orthosilicate Si(OC2H04, often called TEOS, an acronym that also fits the alternative way of naming such a compound, tetraethoxysilane. Thus orthosilicates are actually a sub-set of the larger class of XRSi(OR )3 silanes, where the XR group is also an alkoxy group. The XR and OR groups do not have to be the... 

Sol-gel processing almost exclusively involves metal alkoxides as precursor chemicals. An alkoxide is an alkane with an oxygen interposed between at least one of the carbon atoms and the metal—for example, (OC2H5)4Si, known as tetraethoxysilane (TEOS, a.k.a. tetratethyl orthosilicate). Other common alkoxide precursors are listed in Table 7.15. TEOS is used to produce the sol-gel-derived silica that generated the X-ray diffraction pattern in Figure 1.50. Let us use silica as an example to study the steps in the sol-gel process. 

Throughout the reaction, only tetraethoxysilane is detected from the top phase. The gas chromatograms of the trimethylsilylated derivatives obtained from the bottom phase at various time intervals are shown in Fig. 2. After 1 h of stirring, only the monomer (SiO -) is detected, which would have been formed by the hydrolysis of tetraethoxysilane. After 2 h of stirring, the small peak corresponding to the dimer (SioOy-) appears. It is assumed that the amount of hydrolyzed product of tetraethoxysilane increases with time, and the polymerization proceeds in the bottom aqueous phase. 

Spiral shaped hollow nanofibers were formed from the reaction of p-aminophenyl-p-D-glucopyranoside and p-dodecanoylaminophenyl-p-o-glucopyranoside with excess tetraethoxysilane. The diameter distributions of these tubes ranged from 1 to 2 nm and from 3 to 7 nm. Metal oxide nanotubes derived from this process displayed excellent hydrogen adsorption and storage capacity for potential use in hydrogen-powered vehicles. 

Various methods for anchoring Gp titanium derivatives onto organic or inorganic supports have been developed. Heterogeneous epoxidation catalysts have been prepared by the co-polycondensation of Cp2TiCl2 and (CpTiCl2)20 with tetraethoxysilane by a modified sol-gel procedure, and the use in epoxidations of non-activated olefins have been described.1936... 

Starting with acid-catalyzed hydrolysis and condensation (step 1) of the silica precursor (tetraethoxysilane, TEOS), the viscous product (poly(ethoxy)siloxane, PES) is converted into silica hydrogel beads in a stirring process under basic conditions (step 2). Both the viscosity of the sol-gel derived PES and the stirring speed directly influence... 

The characterization of polysiloxane-modified mesoporous silica gels derived from the acid catalyzed hydrolysis of tetraethoxysilane and oligomeric silanol terminated polydimethylsiloxane using Si CPMAS NMR has been report. ... 

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