Modified silanes

Brook, M.A., Chen, Y., Guo, K., Zhang, Z. and Brennan, J.D. (2004) Sugar-modified silanes precursors for silica monoliths. Journal of Materials Science, 14, 1469-1479. 

Brandhuber, D., Torma, V., Raab, C., Peterlik, H., Kulak, A. and Husing, N. (2005) Glycol-modified silanes in the synthesis of mesoscopically organized silica monoliths with hierarchical porosity. Chemistry of Materials, 17, 4262 1271. 

Markowitz et al. developed a different approach, again in an attempt to overcome some of the inherent difficulties that arise when imprinted bulk materials are used as catalysts [82], Here, the authors used a template-directed method to imprint an a-chymotrypsin TSA at the surface of silica nanoparticles, prepared with a number of organically modified silanes as functional monomers. Silica particle formation was performed in a microemulsion, where a mixture of a non-ionic surfactant and... 

A very attractive method for glassy surface activation is silanization with reactive silanes. Thus, many research groups use aldehyde-modified silanes [25], epoxy silanes [26], and mercapto-silanes [27,28] for generating reactive surfaces. Commonly applied silanes are shown in Fig. 13. In the case of the aldehyde linkage a 5 -amino or hydrazide-modified [29] single strand... 

The surface treatment agent perfluoropolyether-modified silane, (III), was prepared by the author [1] and had improved water/oil repellency, chemical resistance, and antifouling properties. 

The vinyl silane reacts more slowly than the methacrylate in free-radical polymerizations. In addition, vinyl silanes are known to hydrolyze relatively quickly compared to alkyl-modified silanes [4], These two facts make it reasonable to assume that the cause of the oligomerization seen... 

Polyol-Modified Silanes as Precursors for Mesostructured Silica Monoliths... 

Keywords sol-gel chemistry, mesostructured monoliths, glycol-modified silanes... 

Modifications of alkoxysilanes with diols or polyols such as ethylene glycol, glycerol, etc. have been well known since the middle of the last century however, their application was hampered by their hydrolytic instability [7, 8]. Only in recent years is interest in this type of glycol-modified silanes increasing again because of some obvious advantages ... 

The latter point was the one first recognized as an advantage in the synthesis of bio-silica gels as seen in the application of glycerol-modified silanes for the incorporation of otherwise incompatible biomolecules [9, 10]. 

The extraordinarily good compatibility of ethylene glycol-modified silanes with lyotropic liquid-crystal phases of surfactant molecules was demonstrated by Hoffinann in 1998 [11,12]. 

Gel times as a function of pH of the starting solution for EGMS, PGMS, and GLMS modified silanes in the presence of surfactant (Pluronic P123) (note that the gelation time is presented in a logarithmic scale). 

Summary Precursor-derived quaternary Si-B-C-N ceramics frequently possess an enhanced thermal stability compared to SiC, SisN4 or Si-C-N ceramics. The stability of the materials towards crystallization and/or decomposition is directly coimected to the molecular structure and the elemental composition of the polymeric precursors. This paper highlights recent investigations on the synthesis of boron-modified polysilazanes and polysilylcarbodiimides. Hydroboration of polyvinylsilazanes and dehydrocoupling reactions of boron-modified silanes with ammonia or amines as well as cyanamide are described. It is shown that simple organosilicon chemistry provides a means to efficiently optimize ceramic yields and tune elemental composition as well as thermal properties of the polymer-derived ceramics. 

It is known that the advantages of imprinted ormosils (organically modified silanes) over acrylic-based MIPs are their chemical stability, the high thermal stability of sol-gel materials, synthesis in mild temperature conditions, optical transparency, photo-, electro- and chemical stability, all properties that made these materials ideal for use in optical sensing approaches, particularly in aqueous samples.48 50 Although... 

MS-polymers (polymers with moisture-curing modified silane groups),... 

A further modification to these catalysts involves the incorporation of a third, polarity-modifying silane (e. g. PhSi(OMe)3) alongside the aminopropyl silane. The effect of this is quite pronounced, and increases both rate of reaction and the turnover number [30]. 

Recently, Reetz and others have published a number of studies showing that adding organically modified silanes (precursors), such as methyltrimethoxysilane or poly (dimethylsiloxane), to tetraethoxysilane (TEOS) during hydrolysis can produce a protein-doped organicinorganic hybrid material that is hydrophobic [1-7]. Systems already tested... 

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