Bulk nanostructure

Bulk nanostructured materials are soUds with nanosized microstructure. Their basic units are usually nanoparticles. Several properties of nanoparticles are useful for applications in electrochemical sensors [67], However, their catalytic behavior is one of the most important. The high ratio of surface atoms with free valences to the total atoms has led to the catalytic activity of nanostructured SEs being used in electrochemical reactions. The catalytic properties of nanoparticles could decrease the overpotential of electrochemical reactions and even provide reversibility of redox reactions, which are irreversible at the bulk metal SE [68], Multilayers of conductive nanoparticles assembled on electrode surfaces produce a high porous surface with a controlled microenviromnent. These structures could be thought of as assemblies of nanoelectrodes with controllable areas. 

Key words severe plastic deformation, bulk nanostructured materials, strength and ductility... 

Previous investigations have demonstrated that use of HPT provides an ability to produce homogeneous nanostructures with a grain size of about 100 nm and less [7,11,13], These earlier studies have allowed to consider this method as an SPD technique for bulk nanostructured materials processing. 

Similarly, well-ordered bulk nanostructures can also be achieved by triblock copolymers as shown impressively, for example, by Abetz for styrene-butadiene-rert-butyl methacrylate triblock copolymers [13] (Fig. 5.6). 

Bhadeshia HKDH. The first bulk nanostructured metal. Sci Technol Adv Mater 2013 14 014202. 

The development of BCP able to produce bulk nanostructured precursors with volumetric densities of high efficient nucleation domains greater than 10 and preferably approximately 10 nanodomains/cm . Foams produced from these precursors are expected to reach very fine porous structures (<100 nm) and high porosities up to 80-90%. 

Key features of nanostructures that typically are exploited are a high surface area, a short solid state diffusion path, a high aspect ratio (ID materials), fast electron separation and transport, and fast switching of surface charges (inch oxidation state of the entire bulk nanostructure or its surface). Except for these conventional features, specific features to the nanoscale, namely quantum size effects, such as band-gap-widening or ballistic electron transport " may be the target of electrochemical processing. 

R.Z. Valiev, R.K. Islamgaliev, I.V. Alexandrov, Bulk nanostructured materials from severe plastic deformation. Prog. Mater Sci. 45(2), 103-189 (2000)... 

Lan, Y. C., Minnich, A. J., Chen, G., Ren, Z. E. (2010). Etthanex ment of thermoelectric figure-of-merit by a bulk nanostructuring approach. Advanced Functional Materials, 20, 357-376. 

Lopez-Medina, R., Rojas, E., Banares, M. A., and Guerrero-Perez, M. O. Highly active and selective supported bulk nanostructured MoVNbTeO catalysts for the propane ammoxidation process. Catal Today 192,67-71 (2012). 

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