Carbon nanotubes, discovery

Regarding a historical perspective on carbon nanotubes, very small diameter (less than 10 nm) carbon filaments were observed in the 1970 s through synthesis of vapor grown carbon fibers prepared by the decomposition of benzene at 1100°C in the presence of Fe catalyst particles of 10 nm diameter [11, 12]. However, no detailed systematic studies of such very thin filaments were reported in these early years, and it was not until lijima s observation of carbon nanotubes by high resolution transmission electron microscopy (HRTEM) that the carbon nanotube field was seriously launched. A direct stimulus to the systematic study of carbon filaments of very small diameters came from the discovery of fullerenes by Kroto, Smalley, and coworkers [1], The realization that the terminations of the carbon nanotubes were fullerene-like caps or hemispheres explained why the smallest diameter carbon nanotube observed would be the same as the diameter of the Ceo molecule, though theoretical predictions suggest that nanotubes arc more stable than fullerenes of the same radius [13]. The lijima observation heralded the entry of many scientists into the field of carbon nanotubes, stimulated especially by the un-... 

In the theoretical carbon nanotube literature, the focus is on single-wall tubules, cylindrical in shape with caps at each end, such that the two caps can be joined together to form a fullerene. The cylindrical portions of the tubules consist of a single graphene sheet that is shaped to form the cylinder. With the recent discovery of methods to prepare single-w alled nanotubes[4,5), it is now possible to test the predictions of the theoretical calculations. 

Since the discovery of carbon nanotubes (CNTs) in 1991 [I], the band structures for CNTs have been calculated by a number of authors [2-7], They have predicted that CNTs can be metallic, narrow- or broad band-gap semiconductors. After macroscopic quantities of CNTs were synthesized [8], it has become possible to explore their practical properties. 

The synthesis of molecular carbon structures in the form of C q and other fullerenes stimulated an intense interest in mesoscopic carbon structures. In this respect, the discovery of carbon nanotubes (CNTs) [1] in the deposit of an arc discharge was a major break through. In the early days, many theoretical efforts have focused on the electronic properties of these novel quasi-one-dimensional structures [2-5]. Like graphite, these mesoscopic systems are essentially sp2 bonded. However, the curvature and the cylindrical symmetry cause important modifications compared with planar graphite. 

Since the discovery of SWNTs, they have been expected to become the building blocks of the next generation of functional nanomaterials. However, their strong cohesive property and poor solubility have restricted the use of SWNTs for fundamental and applied research fields. One method to overcome these problems is to make the SWNTs more soluble by wrapping them with polymers [31]. At the same time, the fabrication of high-performance carbon nanotube (CNT)-based composites is driven by the ability to create anisotropy at the molecular level to obtain appropriate functions. 

Chemists have been working for a long time with particles having sizes of nanometers. The novelty of recent developments concerns the ability to make nanostructured substances with uniform particle sizes and in regular arrays. In this way it becomes feasible to produce materials that have definite and reproducible properties that depend on the particle size. The development began with the discovery of carbon nanotubes by Ijima in 1991 (Fig. 11.15, p. 116). 

Since their first discovery by Iijima in 1991 [1], carbon nanotubes have attracted a great deal of interest due to their very exciting properties. Their structure is characterized by cylindrically shaped enclosed graphene layers that can form co-axially stacked multi-wall nanotubes (MWNTs) or single-walled nanotubes (SWNTs). Like in graphite, carbon atoms are strongly bonded to each other in the curved honeycomb network but have much weaker Van der Waals-type interaction with carbons belonging to... 

M. Prato, K. Kostarelos, and A. Bianco, Functionalized carbon nanotubes in drug design and discovery, Acc. Chem. Res., 41 (2008) 60-68. 

In most publications, Iijima is given credit for the discovery in 1991 of the nanotube structure of carbon (Iijima, 1991 Bethune et al., 1993 Iijima and Ichihashi, 1993). However, it has been said that Oberlin et al. (1976) also imaged carbon nanotubes, perhaps even SWNTs. Incredibly, nearly a century earlier, there was a study on the thermal decomposition of methane that resulted in the formation of long carbon strands, which were proposed at the time as a candidate for filaments in light bulbs (see Bacon and Bowman, 1957). 

B. Chen, G. Parker II, J. Han, M. Meyyappan, and A. M. Cassell, Heterogeneous single-walled carbon nanotube catalyst discovery and optimization, Chem. Mater. 14, 1891 (2002). 

A wide range of nanosfructured carbons has been discovered since fhe original discovery of carbon nanotubes (CNTs) by lijima in 1991. Carbon nanotubes and nanofibers are nanoscale cylinders of rolled up graphene sheets. 

Another technology being pursued in the search for high-capacity hydrogen storage media is that of carbon nanotubes. Since their discovery in 1991 by Sumio... 

M. Manthioux, V.L. Kuznetsov, Guest editorial Who should be given credit for the discovery of carbon nanotubes Carbon 44 (2006) 1621-1624. 

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