Nano-sized material

Ab-initio quantum chemical calculations at the HF/3-21G level of theory were applied to consider the nature of the active sites of sodalite P-cage of the LTA type zeolite and faujasite structures. Especially, the nature of sodium, potassium and silicon atoms encapsulated within the sodalitic P-cage, and their structural and molecular parameters have been described. We have shown that up to four sodium and four potassium atoms as well as five silicon atoms could be encapsulated within the sodalite P-cage. The unique properties of these nano-size materials relate directly to the encapsulated guest atom containing fragments stabilized within the sodalite P-cage of the LTA type zeolite or faujasite structures. 

The carbon nanotubes possess such properties as high conductivity, excellent strength and stiffness, and chemical inermess. CNTs also show unusual electronic characteristics that are dependent on lattice helicity and elasticity. The density of SWNTs is estimated to be smaller (0.6g/cm ) than graphite due to the presence of hollow channels in the center of CNTs. As expected for nano-sized materials, the surface area of CNTs is very large, e.g. 10-20m /g for MWNTs and the value of SWNTs is expected to be an order of magnimde higher. Some detailed discussion of the mechanical, electronic, and chemical properties of CNTs can be found in the following sections. 

Since the discovery of renowned Kubo s size effect, nano-sized materials have been investigated extensively such as a cluster which is an aggregate of less than 10 atoms or molecules with a diameter of 1 nm or less. Because of an intermediate nature of the cluster between gas and condensed phases, the cluster is sometimes called a material of the fourth phase after gas, liquid and solid phases. The cluster is attractive not only because of its dramatic size-dependent properties but also providing a model for the theory of a few body system, whose size is too small to be treated by statistical physics and thermodynamics but too large and too complicated to be handled by quantum chemistry. 

With nanotechnology techniques, a variety of products can be made to be smaller and more effective. As nano-sized materials used in nanotechnology, proteins can be applied to many fields such as biotechnology, medicine, pharmacy, and advanced materials. Control of self-assembly based on protein-protein interaction enables us to perform a bottom-up design of fiber. Amyloid fiber [1] is one of the examples of... 

There are several modes for the frontal polymerization of metal-containing monomers. One such mode is polymerization in a high-temperature burning regime. This method is followed by thermolysis of the products to obtain metal-containing composites that include nano-sized materials. The kinetic peculiarities of high-temperature pyrolysis of the Co(II) acrylamide complex have been studied [84], The rate of the process is approximately satisfied by a first-order equation of autocatalysis (Eq. 4-26), where k = 4.2-10 exp[-24,000/(7 )] (s ), 0 l.910 ... 

If two or more types of different materials are mixed up and treated in defined conditions (varying with temperature, pressure, and other chemical and physical processes), a composite material with a clear interfacial boundary will be obtained. If a major part of the produced composite consists of polymer, then it is called a polymeric composite. A polymeric composite material is one of the most developed areas of modern science and technology. In addition to composite materials, modern science and technology use nano-sized materials. Such composites are called nanocomposites, whose main attraction is related to very high operation properties, such as flexibility, elasticity, recycling, hardness, resistance to abrasion, and optical and electrical transmission [9]. 

In the last few years, the enhanced interest to nano-sized materials has been developed due to potentially imusual physical properties of those items compared to common substances. The magnetic properties of such substances are of great interest and presently tmder intense investigations [1-9]. 

The homopolymerization of reactive surfactants in the form of assemblies, such as micelles or liquid crystals, have been attempted as a way to freeze the structure and prepare various types of nano-sized materials. Polymerization of micelles has not been entirely successful, however. With both spherical and rod-like micelles, the polymerized aggregates were of much larger size than the original structures. With liquid crystals and, in particular, with vesicles, the result is more promising. Stable vesicles, of interest for drug administration, have been prepared by free-radical polymerization of preformed vesicles. Such vesicles need not be based entirely on polymerizable surfactants. Incorporation of... 

Environment-Friendly Methods for Converting Biodegradable Polyesters into Nano-Sized Materials... 

In addition to the outlined morphological difference between the two types of polymer blends, without and with hydrogen bonding between the blend partners, it turned out that the mechanism of formation of the nano-sized materials is completely different for the one or the other case. Detailed studies on the mechanism of formation of the individual micro- and nanofibrils led to the conclusion that it takes place during the cold drawing via coalescence of the elongated droplets [18], as schematically illustrated in Figure 9.9. 

In addition to the technical and commodity applications [38], another important opportunity for the application of the polymer nano-sized materials is their use for biomedical purposes. As mentioned in the Section 9.1, organ transplantation nowadays practically has no technical problems - the main problem is the lack of donors, and this problem is solved by the tissue engineering. The latter uses scaffolds from polymer materials with specific properties formulated at the beginning of the chapter. 

Comparing the above-described basic requirements for scaffolds, on the one hand, and the fibrillar and/or porous character of the nano-sized materials manufactured via the MFC approach on the other, one can conclude that these materials could be of biomedical interest. Nano-sized biodegradable biocompatible polymers with a 3-D network structure seem to be particularly attractive because of their nanoporosity and extremely high specific surface (Figures 9.5b, 9.6, 9.7a,b, 9.10b, and 9.11). An additional advantage of these materials is the fact that they are manufactured without the use of any organic solvents as water is the only solvent. 

What could be the next challenge The first could be improvement of the mechanical performance of the final nano-sized materials. As demonstrated above, in the cases when H-bonding in polymer blends exists, the final nanomorphology is similar to the 3-D nanofibriiiar network, which does not possess the superior mechanical properties of noninterconnected nanofibrils. Scaffolds with high mechanical performance (e.g., for bones and tendons repair) are frequently needed in tissue engineering, possibly prepared with the use of water only as a solvent. 

Fakirov, S., Bhattacharyya, D., and Panamoottil, S.M. (2014) From bulk polymers to nano-sized materials with controlled nanomorphology. Int. J. 

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