Growth and Sintering of Fullerene Nanotubes

Colbert, Daniel T.; Zhang, J.; McClure, S. M.; Nikolaev, Pavel; Chen, Z.; Hafner, Jason H.; Owens, D. W.; Kotula, Paul Gabriel; Carter, C. Barry; Weaver, J. H.; Rinzler, Andrew G.; Smalley, R. E.

doi:10.1126/science.266.5188.1218

Cited by 291 publications

(126 citation statements)

References 15 publications

Supporting

Mentioning

123

Contrasting

Unclassified

Order By: Relevance

“…The mechanisms that have been proposed can again be split into gas-phase and solid-phase mechanisms. The gas-phase mechanisms are similar to those of fullerenes and involve step-wise addition that lead to tube lengthening instead of cage closure [102]. The solid-phase mechanisms involves a graphitic sheet (or sheets) of carbon rolling up to form cylinders that can be capped to form nanotubes [37].…”

Section: Nanostructureformation Inflamesmentioning

confidence: 99%

Combustion synthesis of fullerenes and fullerenic nanostructures

Goel

Hebgen

Sande

et al. 2002

Carbon

117

View full text Add to dashboard Cite

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...

show abstract

Section: Nanostructureformation Inflamesmentioning

confidence: 99%

Combustion synthesis of fullerenes and fullerenic nanostructures

Goel

Hebgen

Sande

et al. 2002

Carbon

117

View full text Add to dashboard Cite

show abstract

“…The first paper was just a lot of different tubes; it wasn't single-walled nanotubes at all. 12 It was 1993 that the IBM group and NEC Laboratories came out with individual single-walled nanotubes. 13 The world was ready for it before, and it had come and did come at an earlier time, but nobody picked up on it.…”

Section: Pswmentioning

confidence: 99%

A Conversation with Prof. Mildred Dresselhaus: A Career in Carbon Nanomaterials

Weiss¹

2009

ACS Nano

View full text Add to dashboard Cite

show abstract

“…They are found not only on the top surface of the cathode deposit (Ando, 1993) but also deep inside the deposit (Ando & Iijima, 1993). Large-scale synthesis of MWNTs by arc discharge has been achieved (Ebbesen & Ajayan, 1992;Colbert et al, 1994) in He gas. The same methodology could be applied to the synthesis of SWNTs if a graphite rod containing metal catalysts (Fe, Co, etc.…”

Section: Carbon Nanotubes: Fascinating Nano-objectsmentioning

confidence: 99%