Carbon nanotubes multi walled

Fig. 14. High resolution TEM observations of three multi-wall carbon nanotubes with N concentric carbon nanotubes with various outer diameters do (a) N = 5, do = 6.7 nm, (b) N = 2, do = 5.5 nm, and (c) N = 7, do = 6.5 nm. The inner diameter of (c) is d = 2.3 nm. Each cylindrical shell is described by its own diameter and chiral angle [151].

Whereas multi-wall carbon nanotubes require no catalyst for their growth, either by the laser vaporization or carbon arc methods, catalyst species are necessary for the growth of the single-wall nanotubes [156], while two different catalyst species seem to be needed to efficiently synthesize arrays of single wall carbon nanotubes by either the laser vaporization or arc methods. The detailed mechanisms responsible for the growth of carbon nanotubes are not yet well understood. Variations in the most probable diameter and the width of the diameter distribution is sensitively controlled by the composition of the catalyst, the growth temperature and other growth conditions. 

Because of the speeial atomie arrangement of the earbon atoms in a carbon nanotube, substitutional impurities are inhibited by the small size of the carbon atoms. Furthermore, the serew axis disloeation, the most eommon defeet found in bulk graphite, is inhibited by the monolayer strueture of the Cfj() nanotube. For these reasons, we expeet relatively few substitutional or struetural impurities in single-wall earbon nanotubes. Multi-wall carbon nanotubes frequently show bamboo-like defects associated with the termination of inner shells, and pentagon-heptagon (5 - 7) defects are also found frequently [7]. 

Many research opportunities exist for the controlled manipulation of structures of nm dimensions. Advances made in the characterization and manipulation of carbon nanotubes should therefore have a substantial general impact on the science and technology of nanostructures. The exceptionally high modulus and strength of thin multi-wall carbon nanotubes can be used in the manipulation of carbon nanotubes and other nanostructures [212, 213]. 

Many of the carbon nanotube applications presently under consideration relate to multi-wall carbon nanotubes, partly because of their greater availability, and because the applications do not explicitly depend on the ID quantum effects associated with the small diameter single-wall carbon nanotubes. 

Among the several known types of carbon fibres the discussion in this chapter is limited to the electric arc grown multi-walled carbon nanotubes (MWCNTs) as well as single-walled ones (SWCNTs). For MWCNT we restrict the discussion to the idealised coaxial cylinder model. For other models and other shapes we refer to the literature [1-6],... 

Peng, Y. T., Hu, Y. Z., and Wang, H., "Patterned Deposition of Multi-walled Carbon Nanotubes on Self-assembled Monolayers, Chinese Science Bulletin, Vol. 51, No. 2, 2006, pp. 147-150. 

AlexeyevaN, Laaksonen T. 2006. Oxygen reduction on gold nanoparticle/multi-walled carbon nanotubes modified glassy carbon electrodes in acid solution. Electrochem Commun 8 1475-1480. 

Monteiro-Riviere, N.A. et al. (2005) Multi-walled carbon nanotube interactions with human epidermal keratinocytes. Toxicology Letters, 155 (3), 377—384. 

Muller, J. et al. (2005) Respiratory toxicity of multi-wall carbon nanotubes. Toxicology and Applied Pharmacology,... 

Sakamoto, Y. et al. (2009) Induction of mesothelioma by a single intrascrotal administration of multi-wall carbon nanotube in intact male Fischer 344 rats. Journal of Toxicological Sciences, 34 (1), 65-76. 

Cheng, C. et al. (2009) Toxicity and imaging of multi-walled carbon nanotubes in human macrophage cells. Biomaterials, 30 (25), 4152-4160. 

Sato, Y. et al. (2005) Influence of length oncytotoxicity of multi-walled carbon nanotubes against human acute monocytic leukemia cell line THP-I in vitro and subcutaneous tissue of rats in vivo. Molecular BioSystems, 1 (2), 176-182. 

Park, E.J. et al. (2009) Pro-inflammatory and potential allergic responses resulting from B cell activation in mice treated with multi-walled carbon nanotubes by intratracheal instillation. Toxicology,... 

Lacerda, L. et al. (2008) Dynamic imaging of functionalized multi-walled carbon nanotube systemic circulation and urinary excretion. Advanced Materials,... 

Deng, X. et al. (2007) Translocation and fate of multi-walled carbon nanotubes in vivo. Carbon, 45 (7), 1419-1424. 

A classic case is an EC of a faradic type in which an electrode is comprised of Ni(OH)2, MnOOH, etc. active materials. Since in these chemistries the conductivity depends on electrode state-of-charge charge level, they require presence of additional stable conductive skeletons in their structure. Noteworthy mentioning that besides traditional forms of carbon or other conductors that may form such a skeleton, the latest progressive investigations demonstrate the possibility of application of different nanostructured forms of carbon, such as single-wall and multi-wall carbon nanotubes [4, 5], Yet, for the industrial application, highly conductive carbon powders, fibers and metal powders dominate at present. 

Electronically conducting polymers (ECPs) such as polyaniline (PANI), polypyrrole (PPy) and po 1 y(3.4-cthy 1 cncdi oxyth iophcnc) (PEDOT) have been applied in supercapacitors, due to their excellent electrochemical properties and lower cost than other ECPs. We demonstrated that multi-walled carbon nanotubes (CNTs) prepared by catalytic decomposition of acetylene in a solid solution are very effective conductivity additives in composite materials based on ECPs. In this paper, we show that a successful application of ECPs in supercapacitor technologies could be possible only in an asymmetric configuration, i.e. with electrodes of different nature. 

Figure 15.11 An example of a single-walled carbon nanotube (a) and a multi-walled carbon nanotube (b). Multi-walled varieties can consist of numerous tubes within tubes.

Lan el al. [52] have reported an approach for vertically aligning multi-wall carbon nanotubes on diverse substrates treated with polyelectrolyte. The shortened multi-wall carbon nanotubes were first functionalized with acyl chloride in thionyl chloride (SOCl2). 

Amide bond is an effective anchor to connect CNTs to substrate surfaces. Lan et al. [52] covalently assembled shortened multi-walled carbon nanotubes (s-MWNT) on polyelectrolyte films. The shortened MWNT is functionalized with acyl chloride in thionyl chloride (SOCl2) before self-assembling. The FTIR spectrum of self-assem-bled MWNT (SA-MWNT) adsorbed on a CaF2 plate modified with PEI/(PSS/PEI)2 shows two characteristic absorption peaks at 1646cm-1 (amide I bond) and 1524cm-1 (amide II bond) resulting from the amide bond formed between the polyelectrolyte films and s-MWNTs. 

K. Wu and S. Hu, Electrochemical study and selective detn. of dopamine at multi-wall carbon nanotube-Nafion film coated glassy carbon electrode. Microchim. Acta 144, 131—137 (2004). 

P. Zhang, F.H. Wu, G.C. Zhao, and X.W. Wei, Selective response of dopamine in the presence of ascorbic acid at multi-walled carbon nanotube modified gold electrode. Bioelectrochem. 67, 109—114... 

B. Zeng and F. Fluang, Electrochemical behavior and determination of fluphenazine at multi-walled carbon nanotubes/(3-mercaptopropyl)trimethoxysilane bilayer modified gold electrodes. Talanta 64, 380-386 (2004). 

Y.H. Zhu, Z.L. Zhang, and D.W. Pang, Electrochemical oxidation of theophylline at multi-wall carbon nanotube modified glassy carbon electrodes. J. Electroanal. Chem. 581, 303-309 (2005). 

G.C. Zhao, Z.Z. Yin, L. Zhang, and X.W. Wei, Direct electrochemistry of cytochrome c on a multi-walled carbon nanotube modified electrode and its electrocatalytic activity for the reduction of H2O2. Electrochem. Commun. 7, 256-260 (2005). 

G.C. Zhao, X.W. Wei, and Z.S. Yang, A nitric oxide biosensor based on myoglobin adsorbed on multi-walled carbon nanotubes. Electroanalysis 17, 630-634 (2005). 

W.J. Guan, Y. Li, Y.Q. Chen, X.B. Zhang, and G.Q. Hu, Glucose biosensor based on multi-wall carbon nanotubes and screen printed carbon electrodes. Biosens. Bioelectron. 21, 508—512 (2005). 

G. Cheng, J. Zhao, Y. Tu, P. He, and Y. Fang, A sensitive DNA electrochemical biosensor based on magnetite with a glassy carbon electrode modified by multi-walled carbon nanotubes in polypyrrole. Anal. Chim. Acta 533, 11-16 (2005). 

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