Chemical composition nanocomposites

Composites made with carbon nanostructures have demonstrated their high performance as biomaterials, basically applied in the field of tissue regeneration with excellent results. For example, P.R. Supronowicz et al. demonstrated that nanocomposites fabricated with polylactic acid and CNTs can be used to expose cells to electrical stimulation, thus promoting osteoblast functions that are responsible for the chemical composition of the organic and inorganic phases of bone [277]. MacDonald et al. prepared composites containing a collagen matrix CNTs and found that CNTs do not affect the cell viability or cell proliferation [278]. 

A major application of this scientific field is in the production of novel nanocomposite materials with unique characteristics. By changing the processing conditions and chemical composition of the film, it is possible to affect its structure and consequently, its physico-chemical properties. Therefore the key to a successful production of such important materials, specifically, nano structural films of predetermined optical, magnetic, dielectric,... 

A study of the chemical composition, structure, photo- and electroluminescent properties of a planar metal-organic nanocomposite gold island film - A1 oxyquinoline has been performed. 

Nanocomposites in which one of constituent phases has at least one dimension smaller than 100 run have recently attracted much attention as perspective functional materials of broad spectrum of applications. The growing interest to these novel systems is quite understandable since the bulk behavior of materials can be dramatically altered by controlling their cluster nanostructures, and this control can lead to greatly improved performance. Besides, the characteristics of nanomaterials could be purposely tuned not only by the variation of the chemical composition of the clusters but also by variation of their size and size distribution. 

Institution under the Dept, of Chemicals Petrochemicals, Indian Ministry of Chemicals Fertilizers. Prof Nayak has been heading the operations of 15 CIPET centres, situated at different locations in India, over the past 4 years. He has 24 years of research experience in the areas of polymer composites, nanocomposites, blends alloys, recycling technologies biopolymers. Prof Nayak has delivered over 300 presentations at national international conferences, published over 150 research papers and has been awarded 5 patents. 

Clays are classified on the basis of their crystal structure and the amount and locations of elelectric charge (defidt or excess) per unit cell. Crystalline days range from kaolins, which are relatively uniform in chemical composition, to smectites, which vary in their composition, cation exchange p>rop>erties, and ability to expand. The most commonly employed smectite clay for the preparation of polymeric nanocomposites is bentonite, whose main mineral component is montmorillonite (Utracki, 2004). 

TEM. However, this observation is in all cases qualitative and highly localised. A general idea of the morphology of polymer nanocomposites can also be obtained by SEM. The dispersion pattern of the nanomaterial in the polymer matrix may be visualised from SEM micrographs. In addition to topographical information, this also provides the chemical composition near the surface of the nanocomposites or nanomaterials (energy dispersive X-ray spectroscopy, EDX system). 

The well-known nonequilibrium process of plasma chemical synthesis has found practical application for a large number of compounds and compositions. However, in recent years more attractive and well-developed processes of synthesis become gas phase condensation under quasi-equilibrium conditions of moderate heat and mass transfer. This process becomes preferable over latter plasma chemical synthesis due to its ability to control the thermal regime and more flexibility in regard to dispersion and purity of the synthesized product. Uniformity of particle size and chemical composition (powder purity) are essential for fabrication of nanocomposites or dense nanocrystalline materials with improved physical, chemical and mechanical properties. This is because the particle size distribution determines the stability of grains during consolidation of a polycrystal while the concentration of impurities affects properties of grain boundaries and entire material (Table 5.1). 

We provide a literature survey of a number of classical techniques used to quantify the chemical composition of porous silicon, highlighting their general merits and potential limitations with the material. Much of the early literature was focused on photoluminescent material, but increasingly there are studies on nanocomposites where chemical composition analysis is required to assess the degree and uniformity of impregnation or surface attachment. 

In this paper we have demonstrated the application of gas-phase combustion processes to produce nanocomposites with superparamagnetic properties. The combustion process was designed in such a way as to allow for the rapid formation of nano-liquid droplets which would phase segregate, combined with rapid quenching to preserve the microstructure and chemical composition. The resulting material showed superparamagnetic behavior between 155 K and room temperature. 

Marat Ibragimovich Abdullin, DSc, is currently Dean of Technological Faculty and Head of Laboratory at Bashkir State University in Ufa, Russia. He is expert in the fields of chemical physics, physical chemistry, chemistry and physics of high molecular compounds as well as synthesis and modification of polymers (including degradation and stabilization of polymers and composites-nanocomposites). He has published about 750 original papers and reviews as well as several monographs. 

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