Silicate ORMOSIL

Along with these recent technologies, sol-gel entrapped catalysts made of organically modified silicates (ORMOSIL) doped with one or... 

Scanning electron microscopy (SEM) used to investigate the structure of similar organically modified silicate (ORMOSIL) films shows that certain [Ru(dpp)3]2+-doped octyl-triethylorthosilicate (triEOS)-tetra-ethylorthosilicate (TEOS) composites form uniform, crack-free xerogel films (Figure 6.6) that can be used to construct high-sensitivity oxygen... 

PEBBLEs are water-soluble nanoparticles based on biologically inert matrices of cross-linked polymers, typically poly(acrylamide), poly(decylmethacrylate), silica, or organically modified silicates (ORMOSILs), which encapsulate a fluorescent chemo-sensor and, often, a reference dye. These matrices have been used to make sensors for pH, metal ions, as well as for some nonionic species. The small size of the PEBBLE sensors (from 20 to 600 nm) enables their noninvasive insertion into a living cell, minimizing physical interference. The semipermeable and transparent nature of the matrix allows the analyte to interact with the indicator dye that reports the interaction via a change in the emitted fluorescence. Moreover, when compared to naked chemosensors, nanoparticles can protect the indicator from chemical interferences and minimize its toxicity. Another important feature of PEBBLEs, particularly valuable in intracellular sensing applications, is that the polymer matrix creates a separate... 

In this chapter, recent progress in several key areas is reviewed. These areas are catagorized by material classification rather than by end-use application (1) bulk silica optics (2) optically active doped silica glasses (3) gel-polymer composites (4) organically modified silicates (ormosils) and (5) gradient-index glasses. These represent the five most significant developments in the area of bulk optical materials by the sol-gel process to date. 

Another new class of materials developed in recent years is the organically modified silicates (ormosils) [50-53]. As their name implies, ormosils are silicate materials that have been modified at the molecular level with an organic component. These materials are often refered to as molecular composites or nanocomposites [53]. They combine the hardness and strength of an inorganic glass with the fracture toughness of a polymer material [50]. Unlike the composites of the previous section, however, ormosils are prepared from one solution. In this regard, ormosils are more like copolymers than composites, except... 

Figure 25-2. Microstructure of an organically modified silicate (Ormosil). Poly (dimethyl siloxane) chains combine silica blocks derived from hydrolysis of an alkoxysilane, Si(OR)4.

---