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08/2007;
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ABSTRACT: A new production method is presented allowing the production of bulk quantities of fullerenes and other carbon nanomaterials using a 3-phase thermal plasma (260 kW). The main characteristics of this method lie in the independent control of the carbon throughput by injection of a solid carbon feedstock, and the immediate extraction of the synthesised product from the reactor, allowing production on a continuous basis. The currently investigated plasma facility is of an intermediate scale between lab-size and an industrial pilot plant, ready for further up scaling to an industrial size. The influence of a large number of different carbon precursors, plasma gases and operating conditions on the fullerene yield has been studied. At this state, quantities of up to 1 kg of carbon can be processed per hour with further scope for increase, leading to production rates for this type of materials not achievable with any other technology at present.
Proceedings, XVI International Winter school on Electronic Properties of Novel Materials. 10/2002;
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ABSTRACT: More than 99% of the carbon black is presently produced by incomplete combustion processes; the by far dominant one is the 'furnace process' developed 60 years ago. This paper presents a new route in which the cracking operation is carried out in the absence of oxygen thanks to an external electric energy supply given by a plasma arc.
Carbon. 01/2002;
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Technical Proceedings of the 2005 NSTI Nanotechnology Conference and Trade Show "Nanotech 2005".
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17th International Symposiul on Plasma Chemistry ISPC 17.
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High Technology Plasma Processes.
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ABSTRACT: The highly flexible plasma system allows the independent flow control of plasma gas, carbonaceous feedstock and metal catalyst. Further important control parameters include current intensity and product quenching rate yielding in an excellent control of the thermal history of the carbon products. Temperature profiles measured along the reactive flow of carbon particles are presented, mapping time-temperature relations for typical operating conditions. In addition, the principle product families are presented. From the characteristics observed and NT product analysis, it is concluded that the AC plasma technology shows a significant potential for the continuous production of bulk quantities of carbon-based nanotubes of controlled properties and novel tube-like nanostractures.
Fullrenes, nanotubes and carbon nanostructures.
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Proceedings, carbon black world 2002.
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ABSTRACT: The residue is received by ablation of a carbon electrode by arc, laser or solar power, incomplete combustion of hydrocarbons, thermal plasma treatment of carbon powder and condensation of gas forming carbon in an inert or partial inert atmosphere. The carbon is soot, graphite, allotropic carbon or a mixture. The residue is used as hydroxylating agent, wetting agent, additive in rubber compounds, halogenating agent such as chlorine or bromine and oxidizing agent such as potassium permanganate. The residue is converted with ammonia, alkyl or aryl amines and ozone under formation of ozonide and is subjected under cycloaddition, Grignard reaction, electro-chemical reaction, Diels-Alder reaction and fullerene reaction. Donor acceptor Molecule complexes are formed. An independent claim is included for functionalized carbon-containing residue + Die vorliegende Erfindung stellt ein Verfahren zur Weiterverarbeitung des kohlenstoffhaltigen Rückstandes aus der Fulleren- und Kohlenstoff-Nanostrukturen-Herstellung bereit, dadurch gekennzeichnet, dass der Rückstand durch Einbringen von chemischen Substituenten funktionalisiert wird und die Funktionalisierung währen oder nach der Herstellung durchgeführt wird. Ferner wird der nach dem Verfahren erhältliche funktionalisierte kohlenstoffhaltige Rückstand und dessen Verwendung als Hydroxylierungsmittel, Benetzungsmittel, als Zusatz in Gummiverbindungen und zur Tether-gerichteten Fern-Funktionalisierung bereitgestellt.
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ABSTRACT: Different families of carbon nanostructures produced by a continuous plasma process are presented. Due to the flexibility of this original technology, properties of classical carbon black products can be adjusted more freely during synthesis and an even wider range of parameters is accessible. Novel products with distinctive characteristics are observed when treating nanostructured material in the high-temperature plasma. Evaluation of the application properties of selected materials indicates in certain cases an excellent performance. Plasma-synthesised or plasma-treated carbon nanomaterials have an important potential to improve the performance of carbon-black-containing materials.
Fullerenes Nanotubes and Carbon Nanostructures.
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ABSTRACT: A series of carbon blacks and fullerene soot was produced by a 3-phase Alternative Current (AC) plasma technology. Surface properties of parent materials and their oxidized homologues were studied by Fourier transform infra red spectroscopy (FT-IR), pH of the point zero charge (pHPZC) and acid/base titration. Presence of chemically bounded oxygen and hydrogen in the parent materials was attributed to the ageing of the materials, while the considerable differences observed in the material reactivity toward nitric acid were associated with properties of nanostructure, governed by conditions of plasma synthesis method. The most stable materials are the carbon blacks having the highly ordered graphitic structure, prepared in thermal plasma process by hydrocarbons cracking. These materials present a low surface reactivity. On the other hand, the fullerene soot, obtained in helium atmosphere from pure carbon, exhibits a very high surface reactivity, induced by structure desorganization and probably the presence of dangling bonds.
Fullerenes Nanotubes and Carbon Nanostructures.
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Actes des journées scientifiques du Groupe français d'étude de carbone (GFEC 2002).
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ABSTRACT: Plasma carbon black, a new material? For several years already, the Plasma process for carbon black production has been promoted and considered as a threat to the furnace black production. After a brief introduction to the fundamental differences between a partial combustion process and plasma process, plasma blacks have been compared with partial combustion blacks. The plasma blacks have not been optimised but are more a selection of materials based on feedstock and operating conditions. Physico-chemical properties as well as SUM and high resolution TEM micrographs illustrate differences and similarities. Surface heterogeneity of those carbon blacks has been characterised by static gas adsorption. This way the more graphitic nature of the selection of plasma blacks could be demonstrated, explaining the specific behaviour of those blacks in rubber compounds. The specificity of the carbon blacks investigated is not only in the production technique, namely plasma torch, but also in the variety of the row materials used, demonstrating the flexibility of the process. Methane, ethylene, pyrolysis fuel oil and even a renewable vegetable oil have been used.
Rubber Chemistry and Technology Proceedings, American Chemical society, Rubber division meeting.
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ABSTRACT: High-yield syntheses of peculiar carbon nanotubes and carbon `necklace'-like morphologies have been obtained using a sophisticated thermal plasma technology. This method is based on a thermal plasma, which vapourizes the carbonaceous precursor in the presence of metal catalyst. Electron microscopy analyses provide evidences for a `stacked-cup' structure for the carbon nanotubes. Carbon nano-`necklaces' are constituted by the repetition of multi-wall carbon spheres, connected along one direction in a `bell'-like structure, and containing frequently an encapsulated metal particle. Microscopic growth mechanisms are also proposed to interpret both syntheses. Due to their intriguing topology, these new carbon nanotubes and necklaces may find important applications in nano-technology.
Carbon.
