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We investigated the stable structures, electronic and Li-adsorption properties of C 54 H 18 and its substituted sheets X 2 C 52 H 18 (X=B, N, Si, P, S, Al and F) by a semiempirical molecular orbital method. The F 2 C 52 H 18 sheet was found to have a unique structure and adsorb more Li atoms than the other sheets. This result suggests that the F-substitution into disordered carbons may increase the Li-storage in disordered carbons. [ABSTRACT FROM AUTHOR]

Nanocarbons, which have been obtained by controlling the structure and bonding nature at the nanometer scale, can provide highly functional performances. Carbon nanotubes and vapor grown carbon fibers of diameter less than 100 nm can have quantum effects, which are very different from those of conventional carbon fibers. In this paper, preparation and properties of nanocarbon, are demonstrated and discussed. [ABSTRACT FROM AUTHOR]

Two different processes, which lead to formation of multishell fullerenes, are reported and discussed. The first process is 3000°C high temperature treatment of C 60 -containing carbon blacks. The second process is laser vaporization of composite carbon targets, containing C 60 and vapor-grown carbon fibers (VGCF). It has been shown that the laser vaporization technique allows increasing the yield up to 40%. Possible mechanisms of formation of the outer shells are discussed. [ABSTRACT FROM AUTHOR]

Polyparaphenylene (PPP)-based carbon is expected for a high-performance material of a negative electrode of lithium (Li) ion secondary battery, but the details of relationship between characteristics and heat treatment have not been known. In this report, electrochemical and electrical properties of heat-treated PPP-based carbon powder were investigated and the possibility of the use as the negative electrode of Li ion secondary batteries was shown. [ABSTRACT FROM AUTHOR]

Structural characterization of novel nanofibers, so called "cup-stacked type carbon nanofibers" with large hollow core and their potential applications are described as compared with those of tubular type of nanotubes and nanofibers. This novel carbon nanofiber containing peculiar features provide the variety of carbon nanotubes and nanofibers from basic science to application field. [ABSTRACT FROM AUTHOR]

Structural changes of truncated graphitic conical graphene layers (cups) stacked carbon nanofiber by post-treatment, such as oxidation and heat treatment, are described in terms of microstructure and morphology. [ABSTRACT FROM AUTHOR]

Recently, the lattice image of well ordered carbons can be observed pretty easily by high-resolution transmission electron microscopy (HRTEM). In this study, the cross section of the new type carbon nanofiber, of which the special structure was unknown, was observed by HRTEM and the detailed structure was analyzed by image processing. Defects were observed in the ordered structure of this material, that is, the (00·1) lattice planes show large fluctuation in alignment of them and the (10·0) lattice planes make several angles with the (00·1) lattice planes. The average repeat distance d 002 was estimated by HRTEM image and image analysis. [ABSTRACT FROM AUTHOR]

High-resolution transmission electron microscopy study of ball-milled lampshade carbon nanofibers is reported in the present paper. Milled fibers became shorter in length, preserving the lampshade structure with highly ordered graphene layers. We have also shown the simulated model for the shortening process of the fiber. [ABSTRACT FROM AUTHOR]