Carbon nanotube single-wall

Flafner J FI, Bronikowski M J, Azamian B R, Nikolaev P, Rinzier A G, Colbert A T, Smith K A and Smalley R E 1998 Catalytic growth of single-wall carbon nanotubes from metal particles Chem. Phys. Lett. 296 195... 

The diameter distribution of single-wall carbon nanotubes is of great interest for both theoretical and experimental reasons, since theoretical studies indicate that the physical properties of carbon nanotubes are strongly dependent on the nanotube diameter. Early results for the diameter distribution of Fe-catalyzed single-wall nanotubes (Fig. 15) show a diameter range between 0.7 nm and 1.6 nm, with the largest peak in the distribution at 1.05 nm, and with a smaller peak at 0.85 nm [154]. The smallest reported diameter for a single-wall carbon nanotube is 0.7 nm [154], the same as the diameter of the Ceo molecule (0.71 nm) [162]. 

Whereas multi-wall carbon nanotubes require no catalyst for their growth, either by the laser vaporization or carbon arc methods, catalyst species are necessary for the growth of the single-wall nanotubes [156], while two different catalyst species seem to be needed to efficiently synthesize arrays of single wall carbon nanotubes by either the laser vaporization or arc methods. The detailed mechanisms responsible for the growth of carbon nanotubes are not yet well understood. Variations in the most probable diameter and the width of the diameter distribution is sensitively controlled by the composition of the catalyst, the growth temperature and other growth conditions. 

Fig. 17. Schematic models for a single-wall carbon nanotubes with the nanotube axis normal to (a) the 6 = 30° direction (an armchair (n, n) nanotube), (b) the 0 = 0°...

Structurally, carbon nanotubes of small diameter are examples of a onedimensional periodic structure along the nanotube axis. In single wall carbon nanotubes, confinement of the stnreture in the radial direction is provided by the monolayer thickness of the nanotube in the radial direction. Circumferentially, the periodic boundary condition applies to the enlarged unit cell that is formed in real space. The application of this periodic boundary condition to the graphene electronic states leads to the prediction of a remarkable electronic structure for carbon nanotubes of small diameter. We first present... 

Fig. 19. The energy gap FJ, for a general chiral single-wall carbon nanotube as a function of 100 kidt, where dt is the nanotube diameter in A [179].

Fig. 25. Room temperature Raman spectra for purified single-wall carbon nanotubes excited at five different laser wavelengths, showing evidence for the resonant enhancement effect. As a consequence of the ID density of states, specific nanotubes (n, m) are resonant at each laser frequency [195].

Many of the carbon nanotube applications presently under consideration relate to multi-wall carbon nanotubes, partly because of their greater availability, and because the applications do not explicitly depend on the ID quantum effects associated with the small diameter single-wall carbon nanotubes. 

Figure 11.7. Two types of single-walled carbon nanotubes.

The electronic properties of single-walled carbon nanotubes have been studied theoretically using different methods[4-12. It is found that if n — wr is a multiple of 3, the nanotube will be metallic otherwise, it wiU exhibit a semiconducting behavior. Calculations on a 2D array of identical armchair nanotubes with parallel tube axes within the local density approximation framework indicate that a crystal with a hexagonal packing of the tubes is most stable, and that intertubule interactions render the system semiconducting with a zero energy gap[35]. 

Synthesis and Purification of Multi-Walled and Single-Walled Carbon Nanotubes... 

Behaviour of Single-Walled Carbon Nanotubes in Magnetic Fields... 

FIGURE 4.4 Graphene sheet and single-walled carbon nanotube. 

The force effect is applicable to investigation of the mechanical properties of nanomaterials [28, 29]. We measured TERS spectra of a single wall carbon nanotube (SWCNT) bundle with a metallic tip pressing a SWCNT bundle [28]. Figure 2.13a-e show the Raman spectra of the bundle measured in situ while gradually applying a force up to 2.4 nN by the silver-coated AFM tip. Raman peaks of the radial breathing... 

R. E. (2001) Reversible water-solubilization of single-walled carbon nanotubes by polymer wrapping. Chem, Phys, Lett, 342, 265-271. 

Fischer, J. E., Zhou, W., Vavro, J., Llaguno, M. C., Guthy, C HaggenmueDer, R., Casavant, M. J., Walters, D. E. and Smalley R. E. (2003) Magnetically aligned single wall carbon nanotube films Preferred orientation and anisotropic transport properties./. Appl. Phys., 93, 2157-2163. 

Robel, I., Bunker, B. A. and Kamat, P. V. (2005) Single-walled carbon nanotube-CdS nanocomposites as light-harvesting assemblies Photoinduced charge-transfer interactions. Adv. Mater., 17, 2458-22463. 

Guldi, D. M., Rahman, G. M. A., Jux, N., Tagmatarchis, N. and Prato, M. (2004) Integrating single-wall carbon nanotubes into donor-acceptor nanohybrids. Angew. Chem. Int. Ed., 43, 5526-5530. 

Paloniemi, H., Lukkarinen, M., Aaritalo, T., Areva, S., Lerro, J., Heinonen, M., Haapakka, K and Lukkari, J. (2006) Layer-by-layer electrostatic self-assembly of single-wall carbon nanotube polyelectrolytes. Langmuir, 22, 74—83. 

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