Novel method for C60 synthesis: A thermal plasma at atmospheric pressure

Yoshie, Ken‐ichi; Kasuya, Shigeaki; Eguchi, Koichi; Yoshida, Toyonobu

doi:10.1063/1.108089

Cited by 59 publications

(26 citation statements)

References 8 publications

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“…Based on this argument, Wang et al [11] further claimed that low operating pressures would promote the formation of fullerenes because a higher axial velocity obtained by the fast expansion of plasma gas can increase the temperature gradients experienced by fullerenes precursors. But this conclusion disagrees with the experimental observations reported by Yoshie and Cota-Sanchez [6,15].…”

Section: Introductioncontrasting

confidence: 73%

“…Besides, the rarefaction effect prevailing in the low pressure environments may result in a poor heat transfer to particles, leading to an incomplete treatment of the feedstock materials. This would be one of the main reasons why the laser ablation or the arc discharge process is routinely performed at the relatively lower pressure of 2.7 kPa [46], while the RF induction plasma process is conducted at the relatively higher pressure of 66 kPa [6,15,44]. It was also found in our previous experiments that the fullerene yield was in any case higher with high operating pressures than with low operating pressures [15].…”

Section: Discussionmentioning

confidence: 88%

“…To date, it has been demonstrated that various fullerenes can be produced by utilizing different methods of generating carbon vapors followed by the formation of carbon clusters. These methods include the arc discharge [5], arc-jet plasmas [6], non-equilibrium plasmas [7], solar flux [8], resistive or inductive heating of a graphite rod [9], and combustion-based methods [10].…”

Section: Introductionmentioning

confidence: 99%

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Modeling of Induction Plasma Process for Fullerene Synthesis: Effect of Plasma Gas Composition and Operating Pressure

Kim

Moradian

Mostaghimi

et al. 2009

Plasma Chem Plasma Process

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A mathematical model has been developed on the continuous synthesis of fullerenes by direct evaporation of carbon-containing materials using induction thermal plasma technology. The main purpose of this study is to numerically investigate the effect of plasma gas composition and operating pressure on the fullerene formation. The simulation results confirmed that Ar-He mixture plasma is more efficient than argon plasma in terms of the particle evaporation, generation of fullerene precursors, fullerene growth and their annealing, and that low pressure operation would decrease the overall yield rate of fullerenes by enhancing the radial diffusion of carbon vapors towards the reactor walls. Thus an operating condition of relatively high helium content in the plasma gas and elevated gas pressure seems much more desirable for achieving a high yield rate of fullerenes. This conclusion is in line with the experimental evidences reported previously.

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Section: Introductioncontrasting

confidence: 73%

Section: Discussionmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling of Induction Plasma Process for Fullerene Synthesis: Effect of Plasma Gas Composition and Operating Pressure

Kim

Moradian

Mostaghimi

et al. 2009

Plasma Chem Plasma Process

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“…Other methods of fullerene synthesis include ion sputtering and electron beam evaporation of graphite [16], vaporization of graphite using highly concentrated solar heating [17,18], resistive heating of graphite [19], laser ablation of graphite [5,20], inductive heating of graphite [21], and carbon particle evaporation in a hybrid thermal plasma [22]. Several production methods using non-graphitic raw materials have also been studied and found to produce fullerenes.…”

Section: Formation Offullerenes and Nanostructuresmentioning

confidence: 99%

Combustion synthesis of fullerenes and fullerenic nanostructures

Goel

Hebgen

Sande

et al. 2002

Carbon

117

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Fullerenes are molecules comprised entirely of sp 2 -bonded carbon atoms arranged in pentagonal and hexagonal rings to form a hollow, closed-cage structure. Buckyballs, a subset which contains C 60 and C 70 , are single-shell molecules while fullerenic nanostructures can contain many shells and over 300 carbon atoms. Both fullerenes and nanostructures have an array of applications in a wide variety of fields, including medical and consumer products. Fullerenes were discovered in 1985 and were first isolated from the products of a laminar low-pressure premixed benzene/oxygen/argon flame operating at fuel-rich conditions in 1991. Flame studies indicated that fullerene yields depend on operating parameters such as temperature, pressure, residence time, and equivalence ratio. High-resolution transmission electron microscopy (HRTEM) showed that the soot contains nanostructures, including onions and nanotubes.Although flame conditions for forming fullerenes have been identified, the process has not been optimized and many flame environments of potential interest are unstudied. Mechanistic characteristics of fullerene formation remain poorly understood and cost estimation of large-scale production has not been performed. Accordingly, this work focused on: 1) studying fullerene formation in diffusion and premixed flames under new conditions to identify optimal parameters; 2) investigating the reaction of fullerenes with soot; 3) positively identifying C 60 molecules in HRTEM by tethering them to carbon black; and 4) providing a cost estimation for industrial fullerenic soot production.Samples of condensable material from laminar low-pressure benzene/argon/oxygen diffusion flames were collected and analyzed by high-performance liquid chromatography (HPLC) and HRTEM. The highest concentration of fullerenes in a flame was always detected just above the height where the fuel is consumed. The percentage of fullerenes in condensable material increases with decreasing pressure and the fullerene content of flames with similar cold gas velocities shows a strong dependence on length. A shorter flame, resulting from higher dilution or lower pressure, favors the formation of fullerenes rather than soot, exhibited by the lower amount of soot and precursors in such flames. This indicates a stronger correlation of fullerene consumption to soot levels than of fullerene formation to precursor concentration. The maximum flame temperature seems to be of minor importance in formation. The overall highest amount of fullerenes was found for a surprisingly high dilution of fuel with argon. The HRTEM analysis showed an increase of the curvature of the carbon layers, and hence increased fullerenic character, with increasing distance from the burner up to the point of maximum fullerene concentration, after which it decreases, consistent with the HPLC analysis. The soot shows highly ordered regions that appear to have been cells of fullerenic nanostructure formation. The samples also included fullerenic nanostructures such as tubes and sp...

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“…In spite of the apparent advantages, there have been a few attempts on fullerene synthesis from carbon powder in inductively coupled RF or hybrid plasmas [10][11][12][13]. The studies were mainly focused on using carbon black precursor of small particle size to improve evaporation efficiency.…”

Section: Effects Of Precursors and Plasma Parameters Onmentioning

confidence: 99%

Effects of Precursors and Plasma Parameters on Fullerene Synthesis in RF Thermal Plasma Reactor

Szépvölgyi

Marković

et al. 2006

Plasma Chem Plasma Process

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Synthesis of fullerenes from graphite powders of different grade was studied in a radiofrequency (RF) plasma reactor. Dependence of fullerene yield on the properties and feed rate of precursors and on the helium content of plasma gas was studied in details. The fullerene yield was influenced by the mean size and the thermal conductivity of graphite particles on the one hand, and the helium content of the gas phase on the other. Soot containing fullerene mixture of 5.9% was produced in best conditions found in this work. The main component of the fullerene mixture was C 60 . In addition, it contained about 30% of C 70 (corresponding to a C 60 /C 70 mass

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Novel method for C60 synthesis: A thermal plasma at atmospheric pressure

Cited by 59 publications

References 8 publications

Modeling of Induction Plasma Process for Fullerene Synthesis: Effect of Plasma Gas Composition and Operating Pressure

Modeling of Induction Plasma Process for Fullerene Synthesis: Effect of Plasma Gas Composition and Operating Pressure

Combustion synthesis of fullerenes and fullerenic nanostructures

Effects of Precursors and Plasma Parameters on Fullerene Synthesis in RF Thermal Plasma Reactor

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