Nanoparticles carbon nanotubes

Chapter 1 contains a review of carbon materials, and emphasizes the stmeture and chemical bonding in the various forms of carbon, including the foui" allotropes diamond, graphite, carbynes, and the fullerenes. In addition, amorphous carbon and diamond fihns, carbon nanoparticles, and engineered carbons are discussed. The most recently discovered allotrope of carbon, i.e., the fullerenes, along with carbon nanotubes, are more fully discussed in Chapter 2, where their structure-property relations are reviewed in the context of advanced technologies for carbon based materials. The synthesis, structure, and properties of the fullerenes and... 

The final section of the volume contains three complementary review articles on carbon nanoparticles. The first by Y. Saito reviews the state of knowledge about carbon cages encapsulating metal and carbide phases. The structure of onion-like graphite particles, the spherical analog of the cylindrical carbon nanotubes, is reviewed by D. Ugarte, the dominant researcher in this area. The volume concludes with a review of metal-coated fullerenes by T. P. Martin and co-workers, who pioneered studies on this topic. 

Electron irradiation (100 keV) of the sample, heated to 800°C, yields MWCNTs (20-100 nm in length) attached to the surface. Such nanotube growth does not take place if natural graphite, carbon nanoparticles or PTFE are subjected to electron irradiation. The result implies that the material may be a unique precursor for CNTs and may constitute a new preparation method. 

Murr, L.E., Garza, K.M., Soto, K.F., Carrasco, A., Powell, T.G., Ramirez, D.A., Guerrero, P.A., Lopez, D.A., and Venzorlll, J. (2005) Cytotoxicity assessment of some carbon nanotubes and related carbon nanoparticle aggregates and the implications for anthropogenic carbon nanotube aggregates in the environment. International Journal of Environmental Research and Public Health, 2 (1), 31-42. 

There has been a vast increase in publications on carbon nanoparticles, such as Buckminster fullerene (C60) and single-walled nanotubes (SWNTs), since the late 1990s in response to the successful mass production methods of manufacturers... 

The nanostructured surfaces resemble, at least to a certain degree, the architecture of physiological adhesion substrates, such as extracellular matrix, which is composed from nanoscale proteins, and in the case of bone, also hydroxyapatite and other inorganic nanocrystals [16,17,24-27]. From this point of view, carbon nanoparticles, such as fullerenes, nanotubes and nanodiamonds, may serve as important novel building blocks for creating artificial bioinspired nanostructured surfaces for bone tissue engineering. 

Figure 29. Fiuman osteoblast-like MG 63 cells in cultures on material surfaces modified with carbon nanoparticles. A fullerene Cgo layers deposited on carbon fibre-reinforced carbon composites (CFRC), B fullerene C o layers deposited on microscopic glass coverslips, C terpolymer of polytetrafluoroethylene, polyvinyldifluoride and polypropylene, mixed with 4% of single-wall carbon nanohorns, D the same terpolymer with high crystalline electric arc multi-wall nanotubes, E diamond layer with hierarchically organized micro- and nanostmcture deposited on a Si substrate, F nanocrystalline diamond layer on a Si substrate. Standard control cell culture substrates were represented by a PS culture dish (G) and microscopic glass coverslip (FI). Immunofluorescence staining on day 2 (A) or 3 (B-Fl) after seeding, Olympus epifluorescence microscope IX 50, digital camera DP 70, obj. 20x, bar 100 pm (A, C, D, G,H)or 200 pm (B, E, F) [16].

The discovery of fullerenes in 1985 led to the era of nanomaterials.1 The three-dimensional geometry of these molecules as well as their unique properties distinguishes them from conventional molecules encountered in organic chemistry. Due to recent discoveries in this field, the horizons of this area have broadened to encompass various new molecules such as endohedral fullerenes, nanotubes, carbon nanohorns, and carbon nano-onions. This chapter discusses the electrochemical behavior of some of these carbon nanoparticles with special emphasis on endohedral fullerenes. Since a large number of fullerene derivatives have been prepared and their various electrochemical studies in different solvents and electrolytes have been reported, the electrochemistry of these derivatives is beyond the scope of this text.2 3 Among the other carbon nanoparticles, the electrochemistry of derivatives of carbon nanotubes has been reported. These studies have been highlighted in the final part of the chapter. 

Keywords carbon nanoparticles, carbon nanotubes electrochemical treatment transmission electron microscopy particle size. 

Ci LJ, Zhou ZP, Song L, Yan XQ et al (2003) Temperature dependence of resonant Raman scattering in double-wall carbon nanotubes. Appl Phys Lett 82(18) 3098-3100 Osswald S, Behler K, Gogotsi Y (2008) Laser-induced light emission from carbon nanoparticles. J Appl Phys 104(7) 074308-l-074308-6... 

The pressure of inert gas is another important parameter of the arc discharge method. The higher the pressure of helium in the combustion chamber, the better yields of nanotubes will be obtained while at the same time the fraction of carbon nanoparticles is reduced. The proportion of tubes and nanoparticles is about 2 1 in the best samples. At more than 500Torr/9.7psi, however, the overall yields... 

MWNT can also be prepared by laser ablation. Contrary to the synthesis of single-walled nanotubes, no catalyst is added here, but a pure graphite target is vaporized by means of a focused laser beam. The resulting MWNT are precipitated at cooler positions within the reactor. Here as well, the operating temperature is about 1200 °C because the number of defects increases and the yields of MWNT decrease at lower temperatures. Below 200 °C then, no growth of carbon nanotubes is observed anymore. The process produces a considerable portion of amorphous carbon, fullerenes, and carbon nanoparticles besides the desired MWNT. These impurities have to be removed before further use. The yields of multiwalled nanotubes usually range about 40%. 

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