Fullerene soot

Anacleto, J. F., Quilliam, M. A. and Boyd, R. K., Analysis of fullerene soot extracts by liquid chromatography-mass spectrometry using atmospheric pressure ionization , in Proceedings of the 41st ASMS Conference on Mass Spectrometry and Allied Topics, San Francisco, CA, May 30-June 4, 1993, p. 1083. 

Example Fullerene soots as obtained by the Huffman-Kratschmer synthesis of fullerenes can be characterized by positive- as well as negative-ion LDI. [115] The LDI-TOF spectrum of such a sample exhibits fullerene molecular ion signals well beyond m/z 3000 among these, Ceo and 070" are clearly preferred (Fig. 10.11). Furthermore, such samples provide experimental carbon-only isotopic patterns over a wide mass range (Chap. 3.2.1). 

Supported nanoparticles (1-1.5 nm) based on Ru4Pt2 entities have been obtained by using a Ru4Pt2(CO)i8 precursor on carbon black and fullerene soot [63]. XANES analysis showed differences between the interaction of nanoparticles with both carbon black and fullerene supports. In particular, a change in the electronic properties of the nanoparticles on fullerene is proposed this change was related to a strong interaction between the nanoparticle and a surface-atom, probably via the formation of a Ru-carbide phase. 

Different isomers of C qO have been prepared by photooxygenation [48], by MCPBA-oxidation [48], by ozonolysis [49] or they were extracted from fullerene soot [11, 50]. Isolation from fullerene soot and analysis of the product of photooxygenation and thermal ozonolysis yields only [6,6]-closed epoxide structures. As already observed for CgoO, ozonolysis and subsequent photolysis of the ozonide C7QO3 gives different [5,6]-open oxidoannulene structures [49]. 

The reason for this may be attributed to the lower abundance of the parent compounds in fullerene soot, which has prevented their ample use in synthetic investigations. To complicate matters, C76,... 

For the in-rubber investigations, the fullerene soot EP-P434 was used. The plasma-treatment conditions were a RF power of 100 W, an acetylene concentration of 40 Pa, and a treatment time of 2.5 h. 

EP-P434 Fullerene soot 70 Fullerene sites Timcal Graphite and Carbon... 

Hydrophobicity - The surface tension of the fullerene soot before treatment was in the range of 70 mJ/m2 after deposition of polyacetylene it was reduced to... 

Amount of deposited material - Table 4 shows the deposited weight measured with thermogravimetric analysis (TGA) for the different carbon black types after polyacetylene deposition at 27 Pa monomer pressure, 250 W power, and 1 h treatment time. These values show that the most active carbon black is the fullerene soot EP-P434. 

This fullerene soot EP-P434 showed a deposition of 5.5% when the RF power was reduced to 100 W, with 40 Pa acetylene and 2.5 h treatment time. This sample will be discussed in detail later for its in-rubber performance Section 5. 

Morphology - The picture in Fig. 11 clearly shows the coating on fullerene soot primary particles. The thickness of the coating could be quantified as being... 

Application of a plasma coating onto carbon black is very difficult compared to silica. It was only practically feasible for fullerene soot (left over from the fullerene production), which contains a large amount of reactive groups on its surface. Polyacetylene-plasma-treated fullerene soot provides an improved dispersion in SBR and in a SBR/EPDM blend compared to untreated fullerene black. However, the effect on the stress-strain properties is rather limited and the coating has only a slight effect on the final properties. 

Investigations of absorption properties of the sample series thermolysis residue (T), fullerene soot from chamber walls (S2), fullerene soot collected at chamber outlet (SI), and fullerenes (F) were carried out. Also the investigation of hydrogen sorption by graphitized sorbent AI2O3 (A) obtained by original plasma technique [6] was carried out. 

Figure 2. Temperature dependence of desorbed hydrogen mass from different samples SI -fullerene soot collected at chamber outlet surface, S2 - fullerene soot collected from chamber walls, F - fullerenes, T -thermolysis residue, A - graphitized AI2O3...

Keywords arc discharge, fullerene, soot, recrystalized graphite, ionization wave... 

The small amounts of D3-C78 found in fullerene soot and its difficult purification have almost completely impeded the exploration of its chemistry so far.5 62 63... 

Owing to a low abundance in fullerene soot as well, and to a small near-UV extinction coefficient, it took until 1996 for the next higher fullerene, Cso, to be isolated and characterized by 13C NMR spectroscopy.64 The measured resonances were consistent with 20 groups of four symmetry-equivalent carbon atoms, and in combination with theoretical calculations on the structures and... 

A chiral isomer of C2-symmetry (41 13C NMR resonances) has been shown to be the major component in the C82 fraction of fullerene soot.20,58 However, it was not possible to determine experimentally which one of the three C2-symmetric structures among the nine IPR-satisfying C82 isomers11 had been isolated. 

In a similar experiment, derivatization of the C84 fraction of fullerene soot with optically pure bis[(A)-l -phenylbutyl malona(e afforded a series of... 

Following our protocol to separate fullerene isomers by the intermediacy of defined covalent adducts, the fraction of fullerene soot was subjected to Bingel cyclopropanation with bis (.S )-l -phenyl butyl malonate (cf. Section III.C).60 Among the products two chiral mono-adducts and four chiral bis-adducts were isolated in pure state and characterized. An analysis taking into consideration the symmetries of the compounds as deduced from H- or 13 C NMR spectroscopy, the magnitudes of their Cotton effects (these are relatively large, between ca. 10 and 200 M 1 cm-1 in the case of chiral fullerene... 

We pleasantly remember stimulating discussions on chirality and configurational descriptors with Professor Vladimir Prelog. Our work was supported by the Swiss National Science Foundation. We thank Hoechst AG for samples of pure C70 and fullerene-soot extract enriched in higher fullerenes. 

FIGURE 1 An FT-ICR mass spectrum of hot toluene extract of fullerene soot produced by high-temperature laser vaporization of a 10% La20j/graphite composite rod. 

Figure 21 Carbon nanotube production, (a) carbon arc method for multi-walled carbon nanotubes (b) the carbon arc method with metal impregnated rods for single wall nanotube production (c) laser irradiation of metal impregnated graphite for single wall nanotube production (d) hydrocarbon decomposition in presence of a catalyst for multiwall nanotube production (e) fullerene oven to produce graphitic nanoparticles, including short tubes, by heating fullerene soot to high temperatures in vacuum.

In a wholly different approach, nanotubes have also been formed in very low yields by heating fullerene soots to very high temperatures in tantalum ovens in... 

Only the D2 and D2d isomers of Cg4 have been isolated as a 2 1 mixture (D2 D2d) from fullerene soot. None of the other 22 possible isomers [35] have been isolated, although the detection of a third isomer has been recently suggested [35dj. With one exception, all electrochemical studies done on 34 so far have involved the 2 1 mixture of D2 and D2d isomers, and as in the case for the other fullerenes, results have been solvent dependent (see Table 4) [20,24,26,36]. In all solvents studied with the exception of pyridine, there appears to be no difference in the reduction potential of the two isomers i.e., no single reduction exhibits a two-component wave with the 2 1 current intensity ratio expected for the two separate isomers [24,25,36]. In pyridine, however, 10 redox waves are observed, of which the first six have been assigned to the first, second, and third reductions of each isomer with the aid of ESR spectroscopy (see also Table 4) [20]. The only known oxidation of Cg4 has been observed in TCE. The process occurs at +0.93 V versus Fc/Vc (see Fig. 5c) [26]. 

We conclude this chapter with a few brief notes about the availability of fullerenes for research applications. The Budty bibliography database, described in the introduction, lists several commercial suppliers of fullerenes. As of this writing, the quoted price is around 250 per gram of purified Ceo- There are also several detailed descriptions of the construction and operation of fullerene soot reactors and solvent-reflux purification systems in the literature.[Ko91, Kh92]. 

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