Bamboo-Like Carbon Nanotubes

The carbon phase of obtained metal-carbon nanocomposites was shown to contain different types of nanostructured carbon particles in parallel with main graphite-like structures. Bamboo-like carbon nanotubes (CNT) with 14-30 nm in their outer diameter were observed in structured carbon material when GdCl3 was used as a component of composite-precursor (Fig. 4). In this case IR radiation intensity provides the heating of sample to 910 and 1000°C. 

Cui, H., Zhou, O., Zhu, W. and Stoner, B. R., Deposition of aligned bamboo-like carbon nanotubes via microwave plasma enhanced chemical vapor deposition . Journal of Applied Physics, 2000,88, 6072-6074. 

Because of the speeial atomie arrangement of the earbon atoms in a carbon nanotube, substitutional impurities are inhibited by the small size of the carbon atoms. Furthermore, the serew axis disloeation, the most eommon defeet found in bulk graphite, is inhibited by the monolayer strueture of the Cfj() nanotube. For these reasons, we expeet relatively few substitutional or struetural impurities in single-wall earbon nanotubes. Multi-wall carbon nanotubes frequently show bamboo-like defects associated with the termination of inner shells, and pentagon-heptagon (5 - 7) defects are also found frequently [7]. 

The conversion of acetylene on an iron catalyst on Si02-support is a typical example. In this process, acetylene is thermally decomposed by leading it over a bed of catalyst within a quartz tube heated at about 700 °C (500-1000 °C, generally). Apart from the desired MWNT, there are also larger, fibrous structures and layers of amorphous graphene observed. These tend to coat the catalyst particles. The bamboo-like nanotubes (Section 3.3.4) usually obtained from this method are often covered with amorphous carbon too and, in parts, they are considerably curved. In addition to these bent species, there is also a spiral or helical structure... 

Apart from the hitherto described single-waUed and multiwalled carbon nanotubes, there is a variety of further structures with tubular or related geometries. These include bamboo-hke and so-called cup-stacked nanotubes as well as nano-homs and hehcal nanotubes. like normal SWNT and MWNT they consist of curved graphene layers, but they feature additional structural peculiarities that will be considered in the following sections. 

Figure 13.10 (a) Schematic depiction of a multiwaiied carbon nanotube (MWNT) as formed by a series of coaxial rolled-up graphene layers (b) TEM image of multiwaU coaxial nanotubes reported by lijimain 1991 (3). (c) Bamboo-like multiwaiied carbon nanotube. (Reproduced with permission from C. J. Lee et al., Chem. Phys. Lett. 2000, 323, 560.)... 

Heng, L.Y., Chou, A., Yu, )., Chen, Y, and Gooding, J.J. (2005) Demonstrating the advantages of using bamboo-like nanotubes for electrochemical biosensor applications compared to single walled carbon nanotubes. Electrochem. Commun., 7 (12), 1457-1462. 

Eguilaz, M., Ferreyra, N.E, and Rivas, G.A. (2014) Dispersions of hollow and bamboo-like multi-walled carbon nanotubes in polyethyleneimine critical analysis of the preparation conditions and applications for electrochemical sensing. Electroanalysis, 26 (11), 2434- 2444. 

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