Nanostructured inorganic composite materials, 96

Nanostructured materials are nothing new. Chrysotile fibers are an example (Fig. 16.22), as are bones, teeth and shells. The latter are composite materials made up of proteins and embedded hard, nanocrystalline, inorganic substances like apatite. Just as with the imitated artificial composite materials, the mechanical strength is accomplished by the combination of the components. 

Mesostructured aluminophosphate / surfactant composite materials were prepared from aqueous and alcoholic systems. Syntheses in ethanol or methanol, respectively, lead to mixtures of two nanostructured phases. One of these consists of hexagonally arranged rod-like assemblies of the surfactant molecules with the head groups located in the centres, encapsulating the inorganic aluminophosphate the other is lamellar. The syntheses were monitored by in-situ temperature- and time-resolved small angle X-ray scattering (SAXS). 

Nanomaterials energy and applications As nanocrystals and nanotubes are better understood, it becomes possible to rationally design nano-structured materials for specific purposes. This area includes both chemical synthesis and physical properties of nanostructured materials incorporating fullerenes, organic conductive polymers, and inorganic nanostructures. A central goal is composite materials for solar energy utilization—new types of solar cells. 

A variety of nanoeomposite materials designed to mimic the nanostructure and composition of natural bone have been proposed. The most common inorganic component is hydroxyapatite it is the mineral component of bone and indeed it provides good osteoconductivily and adhesion to existing bone tissues. 

Inorganic nanoshell-coated organic polystyrene beads with well-defined nanostructures are attractive because of their applications in the fields of SERS, catalysis, biochemistry, and chemical sensors. The core-shell type composite materials are in the frontier of advanced research, in which the shell component determines the surface properties and the core component indirectly induces the other properties of the system. Bimetallic nanosheUs on functionalized polystyrene beads have been fabricated through a layer-by-layer deposition pathway involving the electrostatic interaction of the polystyrene moiety. 

Abstract Nanostructured organic-inorganic composites have been the source of much attention in both academic and industrial research in recent years. Composite materials, by definition, result from the combination of two distinctly dissimilar materials, the overall behavior determined not only by properties of the individual components, but by the degree of dispersion and interfacial properties. It is termed a nanocomposite when at least one of the phases within the composite has a size-scale of order of nanometers. Nanocomposites have shown improved performance (compared to matrices containing more conventional, micron-sized fillers) due to their high sirnface area and significant aspect ratios - the properties being achieved at much lower additive concentrations compared to conventional systems. 

Current research focuses on the combination of PTs with inorganic materials of high electron affinity, such as nanostructured CdSe or Ti02. Composite materials based on colloidal nanorods of CdSe and P3HT were first reported by Alivisatos to achieve a PCE of 1.7% [445]. Frechet and coworkers have synthesized an end-functionalized PT 252 bearing an aminomethyl group that can effectively disperse CdSe nanocrystals to afford intimate nanocomposites [446]. Depending on the composition of the film, solar cells based on 252 can lead to PCE of 1.6% under solar illumination. 

In the large field of nanotechnology, polymer-based nanocomposites have become a prominent area of current research and development for biomedical applications.In principle, nanocomposites are an extreme case of composite materials in which interface interactions between the two phases, the matrix and the reinforcement, are maximized. In the literature, the term nanocomposite is used for polymers with sub-micrometre dispersions. In polymer-based nanocomposites, nanometre sized particles of inorganic or organic materials are homogeneously dispersed as separate particles in a polymer matrix. Researchers have tried a variety of processing techniques to obtain dense polymer nanocomposite films. The incorporation of nanostructures into polymers can generally be done in different ways as indicated below ... 

Inorganic Aerogel Materials as Nanostructured Energetic Composites... 

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