Nanoscale particle structures composites

Improvements in the properties and performance of fiber-reinforced polymer matrix materials from the addition of nano- and microscale particles have been reported in the literature [8], The availabiHty of different types of nanoparticles offered the possibiHty to tailor fiber/matrix interactions at a nanoscale level. Recently, it has been proven that nanoparticles homogeneously dispersed in a polymer matrix are able to play a beneficial role on the fiber/matrix interfacial adhesion in different types of structural composites [ 11 ], as it will be shown later. Hence, regarding structural properties, nanocomposites appear particularly appropriate as means of enhancing the mechanical properties of conventional composites rather than their use as nanocomposites by themselves, except in some particular cases. 

Structure, composition and electrical properties of YSZ films deposited by ultrasonic spray pyrolysis /. Mater. Sci . 42,3,901-907,0022-2461 Scheeren, C. W. Machado, G. Dupont, J. Fichtner, P. F. P. Texeira, S. R. (2003). Nanoscale Pt(0) particles prepared in imidazolium room temperature ionic liquids Synthesis from an organometallic precursor, characterization, and catalytic properties in hydrogenation reactions. Inorg. Chem. 42,15,4738-4742,0020-1669 Singh, P. Katyal, A. Kalra, R. Chandra, R. (2008). Copper nanoperticles in an ionic liquid an efficient catalyst for the synthesis of bis-(4-hydroxy-2-oxothiazolyl)methanes. Tetrahedron Lett, 49,4,727-720,0040-4039 SusHck, K S. (1988) Ultrasound , VCH, Weinhein, Germany. 

HREM methods are powerful in the study of nanometre-sized metal particles dispersed on ceramic oxides or any other suitable substrate. In many catalytic processes employing supported metallic catalysts, it has been established that the catalytic properties of some structure-sensitive catalysts are enhanced with a decrease in particle size. For example, the rate of CO decomposition on Pd/mica is shown to increase five-fold when the Pd particle sizes are reduced from 5 to 2 nm. A similar size dependence has been observed for Ni/mica. It is, therefore, necessary to observe the particles at very high resolution, coupled with a small-probe high-precision micro- or nanocomposition analysis and micro- or nanodiffraction where possible. Advanced FE-(S)TEM instruments are particularly effective for composition analysis and diffraction on the nanoscale. ED patterns from particles of diameter of 1 nm or less are now possible. 

Possible Mechanisms and Key Characteristics of Nanomaterials. A nanoparticle/nanomaterial is generally defined as a particle/ material having a physicochemical structure greater than typical atomic/molecular dimensions but at least one dimension smaller than lOOnm. It includes particles/ materials engineered or manufactured by humans on the nanoscale with specific physicochemical composition and structure to exploit properties and functions associated with its dimensions. Some of the common nanoparticle types are (1) carbon-based materials (e.g., nanotubes, fullerenes), (2) metal-based materials (e.g., nanogold, nanosilver, quantum dots, metal oxides), and (3) dendrimers (e.g., dendritic forms of ceramics). 

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