P. Bernier

Large-scale production of single-walled carbon nanotubes by the electric-arc technique

Single-walled carbon nanotubes (SWNTs) offer the prospect of both new fundamental science and useful (nano)technological applications. High yields (70–90%) of SWNTs close-packed in bundles can be produced by laser ablation of carbon targets. The electric-arc technique used to generate fullerenes and multi-walled nanotubes is cheaper and easier to implement, but previously has led to only low yields of SWNTs,. Here we show that this technique can generate large quantities of SWNTs with similar characteristics to those obtained by laser ablation. This suggests that the (still unknown) growth mechanism for SWNTs must be independent of the details of the technique used to make them. The ready availability of large amounts of SWNTs, meanwhile, should make them much more accessible for further study.

ELASTIC PROPERTIES OF C AND BX CY NZ COMPOSITE NANOTUBES

We present a comparative study of the energetic, structural, and elastic properties of carbon and composite single-wall nanotubes, including BN,

Doping Graphitic and Carbon Nanotube Structures with Boron and Nitrogen

{\mathrm{BC}}_{3}

Improved structure and properties of single-wall carbon nanotube spun fibers

, and

Characterization of singlewalled carbon nanotubes-PMMA composites

{\mathrm{BC}}_{2}\mathrm{N}

Carbon nanotubes: The solar approach

nanotubes, using a nonorthogonal tight-binding formalism. Our calculations predict that carbon nanotubes have a higher Young modulus than any of the studied composite nanotubes, and of the same order as that found for defect-free graphene sheets. We obtain good agreement with the available experimental results.

ELECTROCHEMICAL INTERCALATION OF LITHIUM INTO MULTIWALL CARBON NANOTUBES

Composite sheets and nanotubes of different morphologies containing carbon, boron, and nitrogen were grown in the electric arc discharge between graphite cathodes and amorphous boron-filled graphite anodes in a nitrogen atmosphere. Concentration profiles derived from electron energy-loss line spectra show that boron and nitrogen are correlated in a one-to-one ratio; core energy-loss fine structures reveal small differences compared to pure hexagonal boron nitride. Boron and carbon are anticorrelated, suggesting the substitution of boron and nitrogen into the carbon network. Results indicate that singlephaase CyBxNx as well as separated domains (nanosize) of boron nitride in carbon networks may exist.

Growth morphologies during cobalt-catalyzed single-shell carbon nanotube synthesis

This letter describes a method to improve the alignment of single-wall carbon nanotubes in macroscopic fibers produced by a simple spinning process. By contrast to classical composite fibers, where the nanotubes are embedded in a polymeric matrix, they consist of an interconnected network of polymers and nanotubes. This network can be swollen and stretched when the fibers are immersed in an appropriate solvent. The nanotubes alignment, studied by x-ray scattering, is significantly improved by the treatment. The fiber Young’s modulus can also be increased by a factor of 4.

Transport properties of PMMA-Carbon Nanotubes Composites

Thin films of poly(methyl methacrylate)-singlewalled nanotubes (PMMA-SWNTs) composite were produced by spin coating using different nanotubes concentrations. Characterization of these new materials was performed by scanning electron microscopy (SEM) and Raman spectroscopy in order to obtain information on the possible interactions between these two materials and especially, on the modifications of the nanotubes and their organization. It is found that in the composite films, the distance between the nanotubes in bundles increases because of the intercalation of polymer. For low nanotube concentrations, amorphous carbon is dispersed in the polymer matrix giving more uniform thin films.

van der Waals interaction in nanotube bundles: Consequences on vibrational modes

Abstract Using the same experimental set-up as for the solar production of fullerenes, we can also produce carbon nanotubes by direct vaporization of a mixture of powdered carbon and catalyst (Co, Ni, Y). The structure of the nanotubes is strongly dependent on the experimental conditions (pressure and flow rate of Ar gas) and we can obtain either multi-walled nanotubes or ropes of single-walled nanotubes.