Inorganic oxides, organic hybrids

Larsen et al. [31] were the first to combine electrospinning with the sol-gel method to obtain the nanofibers made from inorganic oxides and hybrid materials (organic and inorganic). 

Poly(ethylene oxide). The synthesis and subsequent hydrolysis and condensation of alkoxysilane-terniinated macromonomers have been studied (39,40). Using Si-nmr and size-exclusion chromatography (sec) the evolution of the siUcate stmctures on the alkoxysilane-terniinated poly(ethylene oxide) (PEO) macromonomers of controlled functionahty was observed. Also, the effect of vitrification upon the network cross-link density of the developing inorganic—organic hybrid using percolation and mean-field theory was considered. 

N anomaterials have been around for hundreds of years and are typically defined as particles of size ranging from 1 to 100 nm in at least one dimension. The inorganic nanomaterial catalysts discussed here are manganese oxides and titanium dioxide. Outside the scope of this chapter are polymers, pillared clays, coordination compounds, and inorganic-organic hybrid materials such as metal-organic frameworks. 

By the sol-gel-process, inorganic glassy and hybrid polymeric materials are accessible at comparatively low temperatures [1], Therefore, organic molecules or dyes can easily be incorporated into the oxide matrix. This combination is especially attractive for the development of the following devices optical filters, solid-state lasers, optical switches, nonlinear optical laser hosts, optical data storage media, and photoconductive devices and films [2]. 

If R can react with itself or additional components (R contains vinyl, methacryl or epoxy groups, for example), the result of the condensation process is a flexible network of inorganic oxide covalently bonded to organic polymers, namely a hybrid nanocomposite lacking interface imperfections. The properties of this hybrid nanocomposite are intermediate between those of polymers and glasses, and can meet unique requirements. 

The hybrids generated by the sol-gel process combine the flexibility and mechanical strength of the organic constituent with the hardness, stiffness and transparency of the inorganic silica network. Hardness is often further conferred by the employment of other inorganic oxide particles (such as alumina or titania). This first started in the 1980s when... 

There has been a growing interest in inorganic/organic hybrid materials in recent years with expectations for new or improved properties, which are not exhibited or attainable by using the parent materials separately. The usefulness of such materials has been best manifested by recent successful studies of dye-sensitized solar cells, which typically employ thin film electrodes of porous oxide semiconductors such as TiOz, and whose surface is modified with sensitizing... 

Inorganic-organic hybrid POMs have attracted much attention because the electron and steric properties of the POMs significantly affect the catalytic properties of a metal center [88-91]. One hybrid catalyst consisted of a metallo-salen complex attached covalently to a lacunary POM [SiWn039]8- via two propyl spacers. In contrast with an usual Mn(III) salen species, the metallosalen complex modified with the POM afforded a more oxidized Mn(IV) salen-POM or Mn(III) salen cation radical-POM compound [89]. 

Shin JH, Schoenfisch MH. Inorganic/organic hybrid silica nanoparticles as a nitric oxide delivery scaffold. Chemical Materials 2008, 20, 239-249. 

Flexible and oxidatively stable thermosets were prepared by thermally curing linear poly(silarylene-siloxane-acetylene) elastomers at up to 450°C. Thermooxidative weight loss of 3.69% to 7.69% was observed for these crosslinked inorganic-organic hybrid polymers when isothermed at 350°C under air flow. 

The second area that has exploded during the last decade concerns materials that involve open-frameworks that are constructed from both inorganic and organic components we shall refer to them collectively as hybrid materials and wUl cover them in two separate sections. The first will examine the so-called coordination polymers [14] in which molecular coordination compounds are connected by organic linkers to form chains, sheets or 3-D networks. The second class involves extended metal-oxygen-metal networks that are decorated by organic ligands we shall refer to these as hybrid metal oxides. 

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