M. Meyyappan

John Pelesko

Victor Giurgiutiu

Sergey Edward Lyshevski

Nelson Tansu

Ronald Arif

Zhian Jin

Carbon nanotubes (CNTs) were discovered in 1991 [1] by Sumio Iijima of the NEC Corporation. Since then,

research activities exploring their structure, properties, and applications have exploded across the world. Carbon

nanotubes exhibit unique electronic properties and extraordinary mechanical properties, and, hence, have

received attention in nano-electronics, sensors, actuators, field emission devices, high strength composites and a

host of other applications. A detailed discussion on properties, growth, characterization, and application

development can be found in a recent textbook [2]. Here, a brief overview of these subject matters is presented.

Configurationally, a carbon nanotube can be thought of as a two-dimensional graphene sheet rolled up in the

form of a tube. A single-walled carbon nanotube (SWNT) is a tubular shell made of hexagonal rings (in a

sheet) of carbon atoms, with the ends of the shells capped by dome-like half-fullerene molecules. The SWNTs

are classified using a nomenclature (n, m) where n and m are integer indices of two graphene unit lattice

vectors corresponding to the chiral vector of a nanotube (see Figure 4.1) [3]. A multiwalled carbon nanotube

(MWNT) is configurationally a stack of graphene sheets rolled up into concentric cylinders with the ends

either closed with half-fullerenes or left open. Figure 4.2 shows transmission electron microscopy (TEM)

images of a SWNT and a MWNT. The individual SWNTs in Figure 4.2a is about 1 nm in diameter. The

MWNT has a central core with several walls with a spacing close to 0.34 nm between two successive walls

(Figure 4.2b).