Applications of Carbon Nanotubes

Some applications of carbon nanotube-reinforced plastics are tabulated in Table 7.5. 

In addition to the mechanical properties, carbon nanotube-reinforced polymers have interesting electrical properties, in particular, their electrical conductivity 

Electrical Properties of Carbon Nanotube/Polymer-Based Polymers 

Polyethylene carbon nanotube Electrical conductivity and rheological properties 18 

Poly(p-phenylene vinylene) Electrical and optical properties 20 

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Application of carbon nanotubes for high strength composite materials... 

Shvedova, A.A. et al. (2009) Mechanisms of pulmonary toxicity and medical applications of carbon nanotubes two faces of Janus Pharmacology Therapeutics, 121 (2), 192-204. 

A. Bianco, K. Kostarelos, and M. Prato, Applications of carbon nanotubes in drug delivery, Curr. Opin. Chem. Biol., 9 (2005) 674—679. 

M. Valcarcel, B.M. Simonet, S. Cardenas, and B. Suarez, Present and future applications of carbon nanotubes to analytical science. Anal. Bioanal. Chem. 382, 1783—1790 (2005). 

Trojanowicz, M. 2006. Analytical applications of carbon nanotubes A review. Trends in Analytical Chemistry 25 480-89. 

Terrones M (2003) Science and technology of the twenty-first century synthesis, properties and applications of carbon nanotubes. Annual Review of Materials Research 33 419-501. 

Bandaru PR (2007) Electrical properties and applications of carbon nanotube structures. JNanosci Nanotechnol 7 1239-1267. 

Bekyarova E, Ni Y, Malarkey EB, Montana V, McWilliams JL, Haddon RC, Parpura V (2005) Applications of carbon nanotubes in biotechnology and biomedicine. J Biomed Nanotechnol 1 3-17. 

Polizu S, Savadogo O, Poulin P, Yahia L (2006) Applications of carbon nanotubes-based biomaterials in biomedical nanotechnology. J Nanosci Nanotechnol 6 1883-1904. 

Bianco A, Kostarelos K, Prato M (2005) Application of carbon nanotubes in drug delivery. Curr Opin Chem Biol 9 647-649... 

Rakov EG (2001) Chemistry and application of carbon nanotubes. Usp Khim 70 934—973... 

Bio-applications of carbon nanotubes have been predicted and explored ever since their discovery. Significant progress has been made in the effort to overcome many fundamental and technical barriers toward bio-applications. Much of this research is in the field of biosensors to be discussed in the next section. 

The above analysis takes the synthesis methods, the performance affected by the dispersion of CNTs, enhanced physical properties and the latest applications of carbon nanotube/polyurethane composites described in literature reports as the reference point. In the interest of brevity, this is not a comprehensive review, however, it goes through numerous research reports and applications which have been learned and described in the recent years. Despite that, there are still many opportunities to synthesize new carbon nano-tube/polyurethane systems and to modify carbon nanotubes with new functional groups. The possibility of producing modern biomedical and shape memory materials in that way makes the challenge of the near future. 

The unique two-phase structures of polyurethane that offers the elasticity of rubber combined with the toughness and durability of metal make them one of the most extensively studied and frequently used materials in carbon nanotube related nanocomposites. The main difficulty in developing CNT based polyurethane nanocomposites was how to achieve uniform and homogeneous CNT dispersion. Further investigations on the interactions between carbon nanotubes and two-phase structures are critical for the wider applications of carbon nanotube/polyurethane composites. 

The first application of carbon nanotubes in the preparation of a sensor was reported by Britto in 1996. Since then, an increasing number of publications involving sensors based on earbon nanotubes (either single or multi-wall) for substrates like glucose, laetate, aleohols, phenols, neurotransmitters, aminoacids, proteins, carbohydrates among others, have been reported. This fact demonstrates the usefulness of earbon nanotubes for the development of eleetrochemical sensors. 

Molecular wires and molecular switches have been developed for molecular electronics. In particular, much of the progress made in the field of molecular electronics is based on the application of carbon nanotubes. 

The carbon nanotubes can be useful in the separation of molecules not only with different sizes (monomethyl naphthalenes) but also those with different shapes (dimethyl naphthalenes) as demonstrated with a tube of inner diameter of 7.3A. The above results have clearly indicated that the application of carbon nanotubes for gas separation is in very early stage of a technology with far-reaching consequences. The important point brought out is the fact that computational techniques such as MD and CG methods are efficient for screening and designing of carbon nanotubes for selective adsorption and separation of molecules. 

Table 2.3 Applications of carbon nanotube-protein bioconjugates.

Table 2.6 Applications of carbon nanotube-nanoparticle-protein bioconjugates.

Figure 3.110 Application of carbon nanotubes as sensors. A scheme is shown in (a). The electric response upon addition of NO2 or NH3 is clearly dependent on the concentration ((b) and (c)). The arrows indicate the time of analyte addition ( AAAS 2000).

Still for an industrial scale application of carbon nanotubes as filler in polymer materials, their price remains to be markedly reduced. Hence, for the time being, nanotube composite materials are only available for special examinations and applications. 

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