Advanced nanosized

Very few applications for the liquid crystalline structure in food systems are known at present. However, it seems that technologists are starting to discover the potential of the lamellar and cubic phases for entrapment of flavors and for release of active nutraceuticals or additives. Recently [49,50] it was stressed that some advanced nanosized new structures termed cubosomes can be derived from the cubic phases. These unique structures are excellent reservoirs and microreactors for the protection of sensitive materials against oxidation and hydrolysis and as solubilization reservoirs and microreactors for selective processes with high selectivity and specificity. 

There is currently considerable interest in processing polymeric composite materials filled with nanosized rigid particles. This class of material called "nanocomposites" describes two-phase materials where one of the phases has at least one dimension lower than 100 nm [13]. Because the building blocks of nanocomposites are of nanoscale, they have an enormous interface area. Due to this there are a lot of interfaces between two intermixed phases compared to usual microcomposites. In addition to this, the mean distance between the particles is also smaller due to their small size which favors filler-filler interactions [14]. Nanomaterials not only include metallic, bimetallic and metal oxide but also polymeric nanoparticles as well as advanced materials like carbon nanotubes and dendrimers. However considering environmetal hazards, research has been focused on various means which form the basis of green nanotechnology. 

Hence polysaccharides have been viewed as a potential renewable source of nanosized reinforcement. Being naturally found in a semicrystalline state, aqueous acids can be employed to hydrolyze the amorphous sections of the polymer. As a result the crystalline sections of these polysaccharides are released, resulting in individual monocrystalline nanoparticles [13]. The concept of reinforced polymer materials with polysaccharide nanofillers has known rapid advances leading to development of a new class of materials called Bionanocomposites, which successfully integrates the two concepts of biocomposites and nanometer sized materials. The first part of the chapter deals with the synthesis of polysaccharide nanoparticles and their performance as reinforcing agents in bionanocomposites. 

Biopolymers have diverse roles to play in the advancement of green nanotechnology. Nanosized derivatives of polysaccharides like starch and cellulose can be synthesized in bulk and can be used for the development of bionanocomposites. They can be promising substitutes of environment pollutant carbon black for reinforcement of rubbers even at higher loadings (upto SOphr) via commercially viable process. The combined effect of size reduction and organic modification improves filler-matrix adhesion and in turn the performance of polysaccharides. The study opens up a new and green alternative for reinforcement of rubbers. 

Equation 3.1 and Equation 3.2) (including the mean particle sizes obtained) (Adapted from Bonnemann, H. and Brijoux, W., in Surfactant-Stabilized Nanosized Colloidal Metals and Alloys as Catalyst Precursors/Advanced Catalysts and Nanostructured Materials, Moser, W., Ed., Academic Press, San Diego, 1996, pp. 165-196, Chap. 7. With permission from Elsevier Science.)... 

Nanosized materials or nanostructures have dimensions, as their name implies, in the 1-100 nanometer range [5, 6]. It is in this size region that the interaction between biology, chemistry, and physics is the most synergistic. Consequently, it is also an area which may yield truly advanced materials. 

Significant new insight has been gained into the formation of small clusters and nanosized metallic particles [501,502]. This fundamental information is not only inherently fascinating, but it is vitally important for the construction of new generations of advanced nanostructured materials. Evolution of nanosized metallic particles from non-metallic clusters and the chemistries of these species will, therefore, be discussed in the following sections. 

Fine tuning of the Fermi levels of nanosized metallic and size-quantized quasi-metallic particles by adsorbing (or desorbing) charges, ions, or molecules opens the door to the construction of tailor-made advanced materials [538]. 

Powder X-ray diffraction (XRD) is a fundamental technique for the structural characterization of condensed matter. It provides evidence of bulk structures in various dimensions. By coherent scattering, the translational symmetry of a lattice is represented in a diffraction pattern, and the atomic species with their average site occupations are reflected in intensities. In powder diffraction, a full structure analysis has become possible as a result of advances in modeling strategies (Langford and Louer, 1996 McCusker et al., 1999). If the diffracting lattice planes are comparable in their dimensions to the wavelength of the X-rays (i.e., they are nanosized), or if the lattice plane distance is not constant but described by a... 

Among the several drug delivery systems, liposomes - phospholipid nanosized vesicles with a bilayered membrane structure - have drawn a lot of interest as advanced and versatile pharmaceutical carriers for both low and high molecular weight pharmaceuticals. At present, liposomal formulations span multiple areas, from clinical application of the liposomal drugs to the development of various multifunctional liposomal systems to be used in therapy and diagnostics. This chapter provides a brief overview of various liposomal products currently under development at experimental and preclinical level. 

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