Composites with Metals

An alternative approach to improve the electrochemical performance of a TMO anode is the preparation of nanostructures consisting of an inert but conducting metallic core surrounded by a shell of a selected TMO. For this purpose, special synthetic routes allow the hierarchical separation of phases. Thus, the use of electrostatic spray deposition led to the formation CoO/Co composite thin films consisted of hollow spherical particles delivering a high reversible capacity of 1182.1 mAhg at 70th cycle and retaining 69.5% of the initial capacity at 10 C [53]. 

Gold nanoparticles have also been chosen due to their high electronic conductivity, their thermod5mamically stable interface with C03O4, and the potential to catalyze electrochemical reactions at the nanoscale. Belcher et al. propose hybrid gold-cobalt oxide wires prepared by a virus-templated synthesis. The cell delivered 94% of its theoretical capacity at a rate of 1.12 C and 65% at a rate of 5.19 C. Thus, the authors evidenced that nanoscale battery components can be designed and assembled on the basis of biological principles [54]. 

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Alumina fibers for composites with metal and plastics are under development as are structural ceramic products, including engine components. Fine, specialty grades of alumina are also used in toothpaste. 

Comparison of Elastomer Composites with Metal and Plastic Composites... 

Title Polymeric and Carbon Compositions with Metal Nanoparticles... 

Composites with metal and ceramic matrices are in development or evaluation. The high fiber prices and the expensive manufacturing process are hindrances. Fibers for the temperature range of 1.300 to I600°C are being developed. 

Use Special-purpose alloys, cementation of iron, neutron absorber in reactor controls, oxygen scavenger for copper and other metals, fibers and filaments in composites with metals or ceramics, semiconductors, boron-coated tungsten wires, rocket propellant... 

S. Virji, J. D. Fowler, C. O. Baker, J. Huang, R. B. Kaner, and B. H. WeiUer, Polyaniline nanofiber composites with metal salts Chemical sensors for hydrogen sulfide. Small, 1,624-627 (2005). 

Similar relations in samples morphology, were noticed by authors in composites with carbon plasma layers deposited on PP nonwoven fabric. They are still, however, characterised by lower SE compared to composites with metallic layers. Likewise promising results of using carbon layers were presented (Wang et al., 2011), where C layers were deposited by siUc-screen printing. Presented layers were in form of short and long nanotubes, whose length was critical for SE. 

M. K. Bmn, R. A. Giddings, and S. Prochazka, Silicon Carbide Composite with Metal Boride Coated Fiber Reinforcement. U.S. Patent No. 5,316,851, May 31, 1994. General Electric Comp. USA. 

Mathews, F. L. and Rawlings, R. D. (1994). Comporite Materials Engineering and Sderux. Chapter and Hall, London. A wide-ranging introduction to composite materials in their various forms, including composites with metallic or ceramic matrices. Maity (non-numerical) self-assessment questions in addition to some numerical end-of-chapter problems. (Relevant to Chapter 6.)... 

Sugai, A. Colored ink compositions with metallic gloss for writing tools. Jpn. Kokai Xokkyo Koho JP... 

The second case describes the behaviour of composites with metallic matrix. Figure 3.452 b, when ... 

If the failure strain in the matrix is larger than in the fibre, the fibres fracture before the matrix fails. This is frequently the case in composites with metallic or polymeric matrix. Figure 9.3 shows the resulting stress-strain diagram. It is assumed that the matrix yields plastically before the fibre breaks. The material deforms elastically until the matrix yields. On further increasing the strain, the strengthening fibres fracture, and the stress-strain curve drops to a small stress value that lies below that of the pure matrix material because of the reduced volume. Eventually, failure by fracturing of the matrix occurs. The fracture strain is smaller than in a pure matrix material. This is due... 

Table 3 Properties of Epoxy Compositions with Metal-Containing Hardeners... 

James, A. and Miller, T., Performance Comparison of Plastic Composites with Metals for Vertical Body Panel Applications, SAE Technical Paper No. 1999-01-0848, SAE International, Warrendale, PA, 1999. 

Another example of this method is the synthesis of dual Au/Pt composites-the aqueous solutions of polyvinyl alcohol and poly-(JV>vinyl-2-pyrollidone) have been used [39] with polymerization in the solution after colloid particle formation. The aggregation of nanoparticles in this case does not usually take place however the polymerization conditions affect the homogeneity of the composite obtained. They show some catalytic propertks, characteristic of bimetallic catalysts. There were some reports on semiconductor composites with metal coatings such as CdS/Rh 40 A composites [44] and CdSe/Ag SO A composites [45]. The former system exhibits enhanced photochemical properties, the latter was used for investigation of Raman scattering of nanocomposites. 

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