Oxidation of Fullerenes by Ozone

Like typical alkenes, fullerenes can be oxidized by ozone. Epoxidation reaction takes place on C₆₀, and C₆₀On (n=l-5) are formed. Mass spectrometry and chromatography identified the stable existence of two isomers for the dioxides and three for the trioxides in the product mixtures. At lower temperatures, fragmentation occurs and results in the formation of the polar products. C₇₀ and carbon nanotubes also react with ozone but at a much slower rate.     

臭氧催化氧化-活性炭吸附处理DDNP废水

采用臭氧催化氧化-活性炭吸附方法处理DDNP废水,与单独臭氧氧化相比,催化剂的加入可以提高反应后期酸性环境下臭氧的氧化效率。试验选用Fe-活性炭催化组合,在曝气量为70 L/min,臭氧质量浓度为11.5mg/L的情况下处理500 mL废水,1 h后废水中COD、色度、硝基酚类化合物去除率分别达到72.6%、94.3%、80.6%;活性炭吸附处理臭氧催化氧化后DDNP废水可达到《兵器工业水污染排放标准》。当活性炭饱和导致水质超标时,采用臭氧对活性炭进行再生20 min,经反复10次试验,出水水质中COD稳定在131.47~152.96 mg/L,色度和硝基酚类化合物的含量低于排放标准,处理效果良好,具有可重复性。     

Production of Fullerenes by Combustion

Abstract

The progress in the production of fullerenes from flaming soot is reviewed in terms of the experimental conditions, characteristics in the product distribution, and formation mechanisms.     

Production of Fullerenes by Combustion

The progress in the production of fullerenes from flaming soot is reviewed in terms of the experimental conditions, characteristics in the product distribution, and formation mechanisms.     

Time-Resolved Mass Spectrometric Studies of Fullerenes and Endohedral Fullerenes

Abstract

The energetics and dynamics of C₂ evaporations from fullerene radical cations C_n ^?+ were studied with and without ion trapping techniques. Electron space charge trapping was applied in electron ionization experiments. RF trapping in a Paul type ion source was applied for Laser MPI. Appearance energies, kinetic energy releases and metastable fractions were determined. the experimental data were modeled by finite heat bath theory (FHBT) and by RRKM/QET. Evaporation (binding) energies as well as conventional and intrinsic kinetic shifts were deduced. Our results support the following conclusions: (a) C₆₀ sits on the leading edge of a magic shell, with C₅₈ only slightly less stable and C₆₂ considerably less stable than C₆₀; (b) Dissociative decay is able to compete with radiative decay of C₆₀ ^?+ only at internal energies in excess of 37.6 eV (T_b>2300 K); (c) a Ne endohedral atom has a slightly stabilizing effect on the C₆₀ ^?+ cage whereas La is strongly stabilizing the C₈₂ ^?+ cage; (d) C₂ loss is a true evaporation in the sense of having a loose transition state with no reverse activation energy; (e) the C₂ evaporations are statistical in nature and theories such RRKM/QET and FHBT are in excellent agreement with experimental observations.     

Ozone Reaction with C70 and C60 Fullerenes: The Effect of Temperature on the Reaction Kinetics

It has been confirmed that the effect of temperature on the rate constants (k) of ozone reaction with C₇₀ and C₆₀ fullerenes follows the Arrhenius law. The experimental values of activation energy (E_a) and pre-exponential factor (A), like as those of other simple alkenes, are in the order of 2.4-2.6 kcal mol^-1 and (1.2-1.8) × 10⁷ L mol^-1 sec^-1, respectively. They are practically equal for the both fullerenes. It has also been found that the value of the rate constant k of C₇₀ fullerene ozonolysis is higher in comparison to the respective k-value of C₆₀.     

微波等离子体法合成洋葱状富勒烯的研究

在微波等离子体条件下, 以乙炔炭黑/二茂铁为原料, 低温合成纳米洋葱状富勒烯(Nano-structured Onion-like Fullerenes: NSOFs). 采用HRTEM、Raman和XRD等分析方法对产物的形貌、尺寸、微观结构及其物相结构进行了表征. 结果表明, 以乙炔炭黑/二茂铁为原料可大量合成NSOFs, 其外观呈准球状或多面体状、实心、直径分布均匀, 最外碳层由闭合的、呈波浪状的石墨片构成.     

Sulphur Contaminated Fullerenes

We report on the presence of sulphur in a commercial C₆₀/C₇₀ mixture and in C₆₀ separated by column chromatography on activated carbon. By heating under dynamic vacuum, ca. 2 wt% sulphur was eliminated from the mixture and ca. 4 wt% from C₆₀.     

Photoelectrochemical Investigation of Fullerenes

Fullerene solar cells are demonstrated. Illuminated, C₆₀ drives oxidation of redox couples in solution. a photoelectrochemical solid/liquid, rather than a solid state, junction, improves photocurrent, and a C₆₀ single crystal, and not polycrystalline film, decreases dark current, and thereby light driven charge transfer dominates.     

Seminatural Occurrence of Fullerenes

In continuation to our search of fullerenes in usual soots, sixteen additional samples of Chinese ink stick have been analyzed by HPLC. When combined with our previous results, we recognize that C₆₀-content in Chinese ink sticks decreases with time following the first order rate law. This novel observation was interpreted in terms of diffusion-dissipation of C₆₀ molecules through the solid stick.     

Zirconium Cage-Doped Fullerenes

Abstract

Some zirconium containing fullerenes were synthesized by vaporizing a zirconium-containing graphite anode with DC arc discharge technique, extracted by CS2 through low temperature extraction method, and characterized by field desorption mass spectra (FDMS). The results show that these doped fullerenes were zirconium cage-doped fullerenes.     

Fullerenes and Viruses

Abstract

It is well known that any, sometimes very small, changes in the chemical structure can lead to the dramatic changes in biological properties. Therefore it is necessary to divide into two different topics the studies of biological properties of fullerene and fullerene‐like compounds. In the enormous variety of data on the biological activity of fullerenes it is possible to select some with defined mechanism of action. This selection showed that in case of using the fullerene‐containing compositions the main mechanisms of drug action, namely unspecific, specific (ligand–receptor) interaction and membranotropic can be obtained. Therefore fullerenes as compounds with broad biological potential are very promising not only for the design of antiviral compounds, but also for the design of various types of drugs.     

Cycloaddition Reactions of Fullerenes

In the review examples of [1 + 2], [2 + 2], [3 + 2] and [4 + 2] cycloaddition reactions of fullerenes are described.     

Zirconium Cage-Doped Fullerenes

Some zirconium containing fullerenes were synthesized by vaporizing a zirconium-containing graphite anode with DC arc discharge technique, extracted by CS2 through low temperature extraction method, and characterized by field desorption mass spectra (FDMS). The results show that these doped fullerenes were zirconium cage-doped fullerenes.     

Fullerenes in Russia

Structure and main features of the Russian Research Program “Fullerenes and Atomic Clusters” are presented. Results of investigations in the framework of this Program in 1996 are briefly reviewed.     

Seminatural Occurrence of Fullerenes

In continuation to our search of fullerenes in usual soots, sixteen additional samples of Chinese ink stick have been analyzed by HPLC. When combined with our previous results, we recognize that C₆₀-content in Chinese ink sticks decreases with time following the first order rate law. This novel observation was interpreted in terms of diffusion-dissipation of C₆₀ molecules through the solid stick.     

Fullerenes in Russia

Abstract

Structure and main features of the Russian Research Program “Fullerenes and Atomic Clusters” are presented. Results of investigations in the framework of this Program in 1996 are briefly reviewed.