Amorphous carbon domains

Recent investigations have indicated that the aliphatic carbon fraction, rather than aromatic fraction, was strongly correlated to HOC sorption. For instance, the sorption of phenanthrene was related to nonpolar aliphatic carbon fraction, excluding poly(methylene), but was very strongly correlated with the content of the amorphous nonpolar aliphatic domains including amorphous poly(methylene) (Mao et al. 2002). In other words, the rubbeiy, relatively low-density, and amorphous nonpolar aliphatic carbon domains are excellent for phenanthrene partitioning (Figs. 3 and 4). 

Figure 15.9. 13C CPMAS NMR spectrum of humin extracted from a brown chernozem soil from Western Canada. The characteristic doublet in the unsubstituted aliphatic region is characteristic of methylene carbon (28-34 ppm) and shows the presence of both amorphous (soft) domains at 29 ppm and crystalline (rigid) domains at 33 ppm in soil humin. Reprinted from Simpson, M. I, and Johnson, R C. E. (2006). Identification of mobile aliphatic sorptive domains in soil humin by solid-state 13C nuclear magnetic resonance. Environ. Toxi. Chem. 25, 52-57, with permission from the Society of Environmental Toxicology and Chemistry.

Only few attempts have been made to rationally design the mesoscopic fine structure of nanotubes fabricated by wetting nanoporous hard templates with polymeric solutions. Chen et al. infiltrated solutions of PS-fo-PAN in DMF into AAO. As described above, the PAN was at first crosslinked and then carbonized. However, the PS domains were converted into holes, and porous amorphous carbon nanotubes could be fabricated [89]. hi a similar approach, Rodriguez et al. used a solution of PS-fo-PVP and carbohydrates associated with the PVP blocks via hydrogen bonds in DMF into AAO and obtained mesoporous amorphous carbon nanotubes with the positions of the mesopores determined by the positions of the PS domains. Solvent annealing of the BCP/hydrocarbon films in DMF/benzene vapor led to a significantly... 

Carbon blacks are distinguished from most other carbons by their extremely small particle sizes and by the very broad range of particle sizes that can be produced. Primary particles are defined as the roughly spherical regions of rotational crystalline domains within amorphous carbon. The primary particle diameter (fineness) is used to describe the primary particle dimension. Prior to any graphitization treatment, the microstructure of the primary particle is turbostratic. However, significant differences exist between carbon black types that are related to the sizes... 

FIGURE 1.23 Effect of the objective aperture on the bright dot size and position (a) Bright dot size versus size of the Airy disc aperture. Curve A corresponds to amorphous carbon film. Curve B corresponds to localized coherent domains, (b) As aperture size increases in the same position (insets), the bright dot size decreases, (c) Effect of variable defocus (-700 A and zero) upon bright dot images (amorphous state), (d) Effect of same defocus in the case of coherent domains (heat-treated fihn). (Adapted from A. Oberlin, M. Oberlin, and M. Maubois. Study of thin amorphous and crystalline carbon films by electron microscopy. Phil. Mag. 32, 833-846 (1975). With permission.)... 

The initial aim of this review was to clarify and discuss a series of inappropriately used terms, such as amorphous or disordered carbons. In the process of reviewing the available data unexpected new concepts emerged related to the carbonization and graphitization processes, by realizing the importance of heteroatom contribution. The domain of existence of the various substances such as amorphous carbon and BSUs (Section 1.2) and LMO turbostratic carbons (Section 1.3) has thus been defined more precisely (Table 1.13) by using diffraction techniques or their associations (Section 1.1). 

Fig. 3. Correlation of the modified Freundlich coefficient K oc with the weight fraction of (a) nonpolar aliphatic carbon, excluding poly(methylene) and (b) amorphous nonpolar aliphatic carbon in domains, including amorphous poly(methylene). Adapted from Mao et al. (2002).

This approach, however, requires the absence of ill-defined carbon deposits originating from defect-induced soot formation on the surface of nanocarbons during their synthesis. Pyrolytic structures often counteract the control over activity and selectivity in catalytic applications of well-defined nanocarbons by offering an abundance of highly reactive sites, however, in maximum structural diversity. Although some nanocarbons are equipped with a superior oxidation stability over disordered carbons [25], such amorphous structures can further induce the combustion of the well-ordered sp2 domains by creating local hotspots. Thermal or mild oxidative treatment,... 

Nanocarbon hybrids have recently been introduced as a new class of multifunctional composite materials [18]. In these hybrids, the nanocarbon is coated by a polymer or by the inorganic material in the form of a thin amorphous, polycrystalline or single-crystalline film. The close proximity and similar size domain/volume fraction of the two phases within a nanocarbon hybrid introduce the interface as a powerful new parameter. Interfacial processes such as charge and energy transfer create synergistic effects that improve the properties of the individual components and even create new properties [19]. We recently developed a simple dry wrapping method to fabricate a special class of nanocarbon hybrid, W03 /carbon nanotube (CNT) coaxial cable structure (Fig. 17.2), in which W03 layers act as an electrochromic component while aligned... 

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