Fullerenes from a Fulgurite

Daly, Terry; Buseck, Peter R.; Williams, Peter W.; Lewis, C. F.

doi:10.1126/science.259.5101.1599

Cited by 110 publications

(39 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On Earth, fullerenes, primarily C 60 and C 70 , have been extracted from two Cretaceous-Tertiary boundary sites in New Zealand and may be the result of extensive wildfires [39]. They have also been found in fulgurite, a glassy rock that forms when lightning strikes the ground [40], in coal samples found in China [41,42], and in shungite, a carbon-rich Precambrian rock from Karelia, Russia [43]. Fullerenes were also found in residue from the Allende meteorite [44] and the 1.85-billion-year-old Sudbury meteorite impact structure in Ontario, Canada [45].…”

Section: Formation Offullerenes and Nanostructuresmentioning

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: Formation Offullerenes and Nanostructuresmentioning

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

“…Finding anatase within the fulgurite specimen provides further evidence to suggest that the temperature of the glass formation was lower in some regions within the sample than the reported 1800 • C attained, when lightning hits the surface of sand or a rock (Uman 1964;Krider & Dawson 1968). Daly et al (1993) previously reported fullerenes in a fulgurite, though the pathway of fullerenes production could not be definitively linked to the fulgurite formation process (Heymann et al 2003). Graphite has also been observed in fulgurite glasses, presumably resulting from the reduction of organic compounds in the precursor soil (Essene & Fisher 1986).…”

Section: Resultsmentioning

confidence: 94%

A Raman spectroscopic study of a fulgurite

Carter

Hargreaves

Kee

et al. 2010

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

A Raman microspectroscopic study of several fulgurites has been undertaken. A fulgurite is an amorphous mineraloid, a superheated glassy solid that is formed when a lightning bolt hits a sandy or rocky ground and thermal energy is transferred. The Raman spectra revealed several forms of crystalline and fused silica and also the presence of polyaromatic hydrocarbons found in an interfacial zone of a glass bubble. This, together with the presence of anatase, a low-temperature polymorph of TiO 2 , suggested that some regions of the fulgurite specimen were not subjected to temperatures of 1800 • C, which are attained when lightning hits the surface of sand or a rock.

show abstract

“…Rather, alternative ways should be explored as to how these unusual mineral assemblages may have formed. We suggest that they may be the products of lightning strikes (Essene and Fisher, 1986;Daly et al, 1993). Novel ultra-high temperature experiments at >6000 K reported here show that ultra-reduced phases can precipitate directly from plasmas.…”

Section: Introductionmentioning

confidence: 89%

Ultra-high pressure and ultra-reduced minerals in ophiolites may form by lightning strikes

Ballhaus¹,

Wirth²,

Fonseca³

et al. 2017

Geochem. Persp. Let.

View full text Add to dashboard Cite

Since ultra-high pressure (UHP) minerals have been discovered in ophiolites from Tibet and the Polar Urals, it is speculated that the mantle sections of ophiolites may originate deep within the mantle. The UHP minerals are frequently found together with ultra-reduced silicides, carbides, and nitrides. Consequently, it is argued that the deep mantle, or at least domains within it, must be highly reduced, so reduced that practically all transition elements at depth are present in the metallic state. We find it problematic to rewrite the history of ophiolite complexes based on these observations and suggest we should search for alternative and more realistic modes of origin. Electric discharge experiments at >6000 K reported here show that the UHP and highly reduced phase assemblages may precipitate from plasmas. We argue that the mineral assemblages may originate by lightning strikes. As such, they may not record the origin and emplacement history of the mantle lithologies within which they occur.

show abstract

Fullerenes from a Fulgurite

Cited by 110 publications

References 24 publications

Combustion synthesis of fullerenes and fullerenic nanostructures

Combustion synthesis of fullerenes and fullerenic nanostructures

A Raman spectroscopic study of a fulgurite

Ultra-high pressure and ultra-reduced minerals in ophiolites may form by lightning strikes

Contact Info

Product

Resources

About