Nanocarbon materials

Huczko, A. et al. (2005) Pulmonary toxicity of 1-D nanocarbon materials. Fullerenes, Nanotubes, and Carbon Nanostructures, 13 (2), 141—145. Grubek-Jaworska, H. et al. (2006) Preliminary results on the pathogenic effects of intratracheal exposure to onedimensional nanocarbons. Carbon,... 

Nalidixic acid, 3 29 21 104, 123, 215 year of disclosure or market introduction, 3 6t N-alkylation reactions of aniline, 2 785-786 microwaves in, 16 557-558 Naltrexone drug delivery, 9 65—66 Nameplate capacities, 23 547-548 Nametre viscometer, 21 739 NAND arrays, 22 258 Nanoaluminum composites, 10 19, 20 Nanoassemblies, shell and core cross-linked, 20 489-490 Nanocar, 24 62 Nanocarbon materials, 1 718-722 Nanoceramics, 1 705-708 Nanoclays, 11 313-314... 

One synthesis approach that does not rely on CNT formation from the gas phase is molten salt synthesis. The reactor consists of a vertically oriented quartz tube that contains two graphite electrodes (i.e. anode is also the crucible) and is filled with ionic salts (e.g. LiCl or LiBr). An external furnace keeps the temperature at around 600 °C, which leads to the melting of the salt. Upon applying an electric field the ions penetrate and exfoliate the graphite cathode, producing graphene-type sheets that wrap up into CNTs on the cathode surface. Subsequently, the reactor is allowed to cool down, washed with water, and nanocarbon materials are extracted with toluene [83]. This process typically yields 20-30 % MWCNTs of low purity. 

The upscaling of nanocarbon production, while considering purity and homogeneity aspects in the kilogram scale, is a very important factor. Except for multi-walled CNTs no such process has been industrialized so far. If commercially available, high-purity nanocarbon materials provide exorbitant costs of up to several hundred Euro per milligram, which in most cases is inacceptable for applied research. As a consequence, nanocarbons are often synthesized in-house, which substantially lowers the comparability among different studies. Synthesis, characterization, and application must go hand-in-hand to exploit the full potential of nanocarbons. 

The protons/electrons produced in water oxidation at a photoanode side of a PEC device could be used (on the cathode side) to reduce C02 to alcohols/hydrocarbons (CH4, CH30H, HC00H, etc.). In this way, an artificial leaf (photosynthesis) device could be developed [11]. While nanocarbon materials containing iron or other metal particles show interesting properties in this C02 reduction [106], it is beyond the scope of this chapter to discuss this reaction here. It is worthwhile, however, to mention how nanocarbon materials can be critical elements to design both anode and cathode in advanced PEC solar cells. Nanocarbons have also been successfully used for developing photocatalysts active in the reduction of C02 with water [107]. 

Over the last decade, novel carbonaceous and graphitic support materials for low-temperature fuel cell catalysts have been extensively explored. Recently, fibrous nanocarbon materials such as carbon nanotubes (CNTs) and CNFs have been examined as support materials for anodes and cathodes of fuel cells [18-31], Mesoporous carbons have also attracted considerable attention for enhancing the activity of metal catalysts in low-temperature DMFC and PEMFC anodes [32-44], Notwithstanding the many studies, carbon blacks are still the most common supports in industrial practice. 

Abstract. The model for describing the electrical conductivity of nanocarbon material, consisting of the particles of disordered carbon, carbon nanotubes and the ordered carbon phase is proposed. 

Nanocarbon material (NCM), containing both the ordered carbon structures (carbon nanotubes (CNT), the particles of nanographite) and the particles of the disordered carbon phase, is known to be promising for using as elements of the nanodimensional devices and as fillers, for example, of lithium batteries. Structure and phase composition of NCM depend essentially on the methods of their obtaining and the regimes of the subsequent temperature and chemical treatment. Therefore, finding the correlation between the structural and phase composition and transport properties of NCM as well the description of the mechanisms of their conductivity are the important problems. 

Ovsiyenko I., Matzui L., Len T., Kopan V., Scharff P. Structural characteristics of different types of nanocarbon materials. Proceedings of the Int. Conf. Carbon - 2004 (on CD). 

Abstract. Nanocarbon materials and method of their production, developed by TMSpetsmash Ltd. (Kyiv, Ukraine), are reviewed. Multiwall carbon nanotubes with surface area 200-500 m2/g are produced in industrial scale with use of CVD method. Ethylene is used as a source of carbon and Fe-Mo-Al- mixed oxides as catalysts. Fumed silica is used as a pseudo-liquid diluent in order to decrease aggregation of nanotubes and bulk density of the products. Porous carbon nanofibers with surface area near 300-500 m2/g are produced from acetylene with use of (Fe, Co, Sn)/C/Al203-Si02 catalysts prepared mechanochemically. High surface area microporous nanocarbon materials were prepared by activation of carbon nanofibers. Effective surface area of these nanomaterials reaches 4000-6000 m2/g (by argon desorption method). Such materials are prospective for electrochemical applications. Methods of catalysts synthesis for CVD of nanocarbon materials and mechanisms of catalytic CVD are discussed. 

Nanocarbons are among the most promising materials developed last years. Nanocarbon materials include fullerenes, carbon nanotubes (CNT), carbon nanofibers (CNF), nanodiamond, onions, and various hybrid forms and 3-dimensional structures based on these. Several years ago these materials were available in milligram-scale quantities. Now many of them are produced by tones per year. TMSpetsmash Ltd. research team has developed some new kinds of nanocarbon materials and processes for their production. 

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