Process for manufacturing single-wall carbon nanotubes

Abstract

A process for manufacturing single-wall and multiwall carbon nanotubes, comprising the stage of ablation by pulsed electronic beams of a graphite target that contains metallic catalysts.

Description

TECHNICAL FIELD[0001]The present invention relates to a process for manufacturing single-wall carbon nanotubes.[0002]More specifically, the present invention relates to the preparation of nanoparticles (clusters) of carbon formed by nanotubes or nanofibers and particularly to the preparation of single-wall-nanotubes or SWNT.BACKGROUND ART[0003]Carbon nanotubes can be classified into two large categories: multiwall nanotubes and single-wall nanotubes. These two categories of nanotubes form two very different kinds of material in terms of structure and synthesis.[0004]Multiwall carbon nanotubes comprise a plurality of single-wall carbon nanotubes arranged concentrically.[0005]Nanotube physics is an interesting overlap of molecular physics along the transverse cross-section and of solid-state physics along the axis. In a manner similar to fullerene crystals, where the C60 molecules can be arranged in an orderly manner to form a crystal, the nanotubes can be arranged in bundles of nanot...

AI Technical Summary

Benefits of technology

[0022]A particular object of the present invention is to provide a process that allows to obtain carbon nanotubes in which the content of single-wall nanotubes is higher than the content of multiwall nanotubes.

[0023]Another object of the present invention is also to provide a process that is more simple and effective and has a lower energy consumption.

[0040]a) the yield (in terms of ablated material) per pulse (for an equal energy carried by a single pulse) is higher because of the higher efficiency of the energy release process on the part of the electrons with respect to the photons of the laser;

[0042]c) the lower cost of the channel-spark system with respect to laser ablation systems, the lower energy consumption and the greater simplicity of the system allow, for an equal cost, the simultaneous use of at least three devices.

Problems solved by technology

Although it is possible to achieve an exceptionally high quality of SWNTs grown in this manner, this technique has an important disadvantage, i.e., it allows only to produce fractions of a gram per hour.

Moreover, the production costs of single-wall carbon nanotubes by using this technique are currently very high, currently approximately 1000 euros per gram, and this limits its possible applications.

This technique produces relatively large quantities of low-purity material.

The subsequent purification stages provide equally low yields with respect to laser ablation, which has comparable costs.

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