Carbon nano tubes properties

The newest addition to the forms of elemental carbon is the nanotube. A carbon nanotube is a long cylinder of carbon atoms, connected together in much the same way as in a fullerene. Both the diameter and the length of carbon nano-tubes can vary. Properties of nanotubes, such as their ability to conduct electrical charge, change dramatically with the dimensions of the tube. Carbon nanotubes are under intensive study. For example, a carbon nanotube laid down on a silicon chip forms a molecular transistor. Such devices may eventually lead to further miniaturization of the chips that are at the heart of modem computers. 

Nano-photosynthesis can produce sugar and starch for food and further synthesis of cellulose can produce paper and wood to avoid clear-cutting forests. Carbon retrieved from the atmosphere and recycled from existing wastes by MNT will be used to make carbon nano-tubes, with superior properties to steel. Carbon will be the most common structural and functional element for a MNT-based civilization [32,33]. A carbon-based MNT material production model is conceptualized as in Fig. 9. If there is a specific need for metal, a nano-factory with trillions of nano-assemblers will synthesize steel, copper, and alloys in order to skip mining and refining [32,33]. Therefore, industrial wastewater, hazardous wastes and air pollution will all vanish. 

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. 

Synthesis and Properties of PEEK/Carbon Nano tube Nanocomposites... 

Dominicis and Fantoni present a method for the computation of the electronic first hyperpolarizability of chiral carbon nano-tubes (CNTs). The CNT eigenstates are computed by an algorithm reported by Damnjanovic et al. They discuss the symmetry properties of CNTs and selection rules for electronic transitions and demonstrate that the use of symmetry reveals the state-to-state transitions, which contribute to the first hyperpolarizability of CNTs. The latter is related to particular state-to-state transitions. The principles for predicting the magnitude of the first hyperpolarizability and its relation to the topology of CNTs are also discussed. 

Saito, R., Dresselhaus, G., and Dresselhaus, M.S. (1998) Physical Properties of Carbon Nano tubes, Imperial College Press, London. 

Sun, X., Chen, T., Yang, Z., Peng, H., 2013a. The Alignment of carbon nano tubes an effective route to extend their excellent properties to macroscopic scale. Acc. Chem. Res. 46, 539-549. 

Chen, X. L. and Liu, Y. J. Square representative volume elements for evaluating the effective material properties of carbon nano tube-based composites. Comput Mater Sci., 29, 1-11 (2004). 

Donaldson, K, Aitken, R., Tran, L., et al., 2006. Carbon nano-tubes a review of their properties in relation to pulmonary toxicology and workplace safety. Toxicological Sciences 92 (1), 5-22. 

The functionalized carbon nano tubes can present different mechanical and electrical properties when compared to the unfimctionalized carbon nanotubes. These chemically modified structures can be used to facilitate the interaction of the nanotubes with organic and biological molecules and with other chemical groups as toxic molecules, drugs, and even viruses and bacteria (FUho and Fagan 2007). 

Wang YH, Lin J, Huan CHA, Macroscopic field emission properties of aligned carbon nanotubes array and randomly oriented carbon nano tubes layer. Thin Solid Films, 2002.405(1-2) 243-247. 

By applying cationic polymerization of tetrahydrofuran starting from the carbonyl chloride group-functionalized multiwalled carbon nano tubes (MWNT) with silver perchlorate as a catalyst poly-THF was chemically anchored to MWNT surfaces affecting their properties. 

---