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Filamentous carbon is a carbon-containing deposit structure that refers to several allotropes of carbon, including carbon nanotubes, carbon nanofibers, and microcoils.〔 It forms from gaseous carbon compounds. Filamentous carbon structures all contain metal particles. These are either iron, cobalt, or nickel or their alloys. Deposits of it also significantly disrupt synthesis gas methanation.〔 Acetylene is involved in a number of method of the production of filamentous carbon. The structures of filamentous carbon are mesoporous and on the micrometer scale in dimension. Most reactions that form the structures take place at or above . Filamentous carbon's applications include cleaning up spills of crude oil and the creation of strong and lightweight composites. Filamentous carbon also has significantly different thermodynamic properties from graphite, another form of carbon. However, filamentous carbon partially consists of graphite sheets. ==Properties== Filamentous carbon structures typically range between 10 and 500 nanometers in diameter. They are typically 10,000 nanometers (10 micrometers) long. They have a duplex structure. The outside of the structures is difficult to oxidize, but the core oxidizes more easily. A metal particle is typically located at the growing end of the structure, although it is sometimes found in the middle of it instead. Also, more than one filament can sometimes grow out of one metal particle. Filamentous carbon is either helical, straight, or twisted.〔 It contains graphite layers in a conical shape.〔 They planes of graphite located close to the interface between the carbon and the nickel atom in the filament are parallel to the interface. The filaments can also be hollow. Filamentous carbon has thermodynamic properties that are different from those of graphite. This is partially due to the fact that the structure of filamentous carbon is more disordered than the structure of graphite. Other theories on the difference in properties include that the deviation is based on the formation of an intermediate phase of carbides. This theory was proposed by De Bokx ''et al.'' and Manning ''et al.''. However, it is unlikely if the central metal atom is nickel because in that case, since carbides decompose at , and carbides formation was not observed during such a reaction.〔 A difference between the solubities of metal and filamentous carbon also allows carbon diffusion to occur.〔 When the allotrope engages in a gasification reaction below , the reaction's activation energy is approximately 178 kilojoules per mole.〔 Filamentous carbon is mesoporous and has unusual textural properties.〔 It also has paramagnetic properties. It also has a high level of mechanical strength. The nickel particles located in filamentous carbon that is grown in methane and hydrogen gas between and tend to be pear-shaped at the higher end of the temperature range. At higher temperatures, the metal particle becomes deformed. The length of the conic structure of the filaments also increases with temperature. When a copper and silica catalyst is exposed to methane and hydrogen at , hollow, long filamentous carbon structures were formed, and these also contained drops of metal. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Filamentous carbon」の詳細全文を読む スポンサード リンク
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