Silicon organic-inorganic hybrids

Silicone co-polymer networks and IPNs have recently been reviewed.321 The development of IPNs is briefly described, and the definitions of the main (non-exclusive) classes of the IPNs are cited. Examples of latex IPNs, simultaneous and sequential IPNs, semi-IPNs, and thermoplastic IPNs are provided. The use of silicone-silicone IPNs in studies of model silicone networks is also illustrated. Networks in which siloxane and non-siloxane components are connected via chemical bonds are considered co-polymer networks, although some other names have been applied to such networks. Today, some of the examples in this category should, perhaps, be discussed as organic-inorganic hybrids, or nanocomposites. Silicone IPNs are discussed in almost all of the major references dealing with IPNs.322-324 Silicone IPNs are also briefly discussed in some other, previously cited, reviews.291,306... 

Research of biologically active silicone materials continues. The synthesis and characterization of polysiloxanes having bioactive pendant groups,556 557 and the preparation of bioactive porous organic-inorganic hybrids for medical applications,558 have been reported. 

Pyun, J. Xia, J. Matyjaszewski, K. Organic-Inorganic Hybrid Materials from Polysiloxanes and Polysilsesquioxanes Using Controlled/ Living Radical Polymerization. In Synthesis and Properties of Silicones and Silicone-Modified Materials Clarson, S. J., Fitzgerald, J. J., Owen, M. J., Smith, S. D., Van Dyke, M. E., Eds. ACS Symposium Series 838 American Chemical Society Washington, DC, 2003 pp 273—284. 

Figure 3.12 Examples of building blocks of organic-inorganic hybrid materials along with their names according to a rational nomenclature system that is already applied in the field of silicone research.

We are nowhere close to knowing the potential benefits that nanoscale silicone resin networks, with their special structure-effect relationship, will be able to offer irmovative technologies of the future (nanotechnology). By virtue of their organic-inorganic hybrid nature, silicones open up new paths to special functionalities and enhanced properties of materials. 

Schmidt (35) demonstrated that alkyl substituents enhance ligand electron donation. Hydrolysis is enhanced under acidic conditions, but is retarded under basic conditions, by methyl substitution of ethoxysilane derivatives. This result is important for the generation of organic-inorganic hybrid materials. When TEOS is reacted with silicon monomers containing alkyl substituents (or organic polymers with trialkoxysilane groups), the relative reaction rates just described must be controlled to produce true hybrids and avoid blocky materials. 

Our attempt to obtain a silicon-boron hybrid polymer system was successful. Their complicated crosslinkable structure acts as a thermosetting resin to give thermal and mechanical stability with good processability. Carborane hybridization gives exceptional non-flammability. This is a kind of organic-inorganic hybrid system that has plastic versatility and ceramic stability. 

An organic-inorganic hybrid composite was prepared from silicon nanoparticles [90]. Silicon nanopar-... 

Organic-Inorganic Hybrids towards the Preparation of Porous Silicone Resin Thin Films 697... 

Other unusual additives include oxetanes, vinylic macromono-mers, silicon carbide, superconductive carbon blacks, silver-coated fly ash, metal oxides, Tb for green emission, antibacterial agents, and organic-inorganic hybrid copolymer fibers. In an interesting reversal, transition element acetylacetonate salts were decomposed in a PDMS matrix to give membranes with catalytic activity. ... 

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