Single-wall CNTs

In this chapter the results of detailed research on the realistic electronic structure of single-walled CNT (SWCNT) are summarised with explicit consideration of carbon-carbon bond-alternation patterns accompanied by the metal-insulator transition inherent in low-dimensional materials including CNT. Moreover, recent selective topics of electronic structures of CNT are also described. Throughout this chapter the terminology "CNT stands for SWCNT unless specially noted. 

Realistic samples contain CNTs with different layer numbers, circumferences, and orientations. If effects of small interlayer interactions are neglected, the magnetic properties of a multi-walled CNT (MWCNT) are given by those of an ensemble of single-walled CNTs (SWCNTs). The distribution function for the circumference, p(L), is not known and therefore we shall consider following two different kinds. The first is the rectangular distribution, p(L) = mn)... 

FIGURE 32.3 The electrophilic Fukui function of single-wall CNT is plotted as an isosurface with a grid of 0.2 A. 

FIGURE 32.4 (See color insert following page 302.) The localized minima as obtained after the GCMS simulation with carbon dioxide adsorption over single-wall CNT with a fixed fugacity of 100 kPa. 

CNTs have a different porous structure than activated carbon. The specific surface area of CNTs can range from 50 m2/g (multi-walled CNTs with 50 graphene walls) to 1315 m2/g (single-walled CNTs). Theoretically, the porous structure of CNTs is identical to the tubular structure of CNTs and the pore sizes of CNTs correspond to the inner diameters of opened CNTs and should have a narrow distribution. Activated carbons usually have a broad pore distribution covering micropore, meso-pore and macropore ... 

Comparison between Selected Properties of Single-Walled CNTs (SWCNTs) and Competitive Materials or Techniques... 

The 0-d nanoparticles can be nano-metal oxides (such as silica,1 titania,2 alumina3), nano-metal carbide,4 and polyhedral oligomeric silsesquioxanes (POSS),5 to name just a few the 1-d nanofibers can be carbon nanofiber,6 and carbon nanotubes (CNT),7 which could be single-wall CNTs (SWCNT) or multiwall CNTs (MWCNT) etc. the 2-d nano-layers include, but are not limited to, layered silicates,8 layered double hydroxides (LDH),9 layered zirconium phosphate,10 and layered titanates,11 etc. 3-d nano-networks are rarely used and thus examples are not provided here. 

Figure 1. The diagram of physicochemical reaction for welding two single-walled CNT.

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