Carbon nanotubes growth mechanism

Key Words—Carbon nanotubes, vapor-grown carbon fibers, high-resolution transmission electron microscope, graphite structure, nanotube growth mechanism, toroidal network. 

As authors supposed from the generally accepted concepts of mechanisms of carbon nanotube growth, the dispersed nickel sputtered must catalyze the growth of these nanotubes. The source for carbon should be carbon from the hydrocarbon that transforms into the vaporous state in the arc zone. It has been supposed to prepare single-wall nanotubes on the nickel particles 1-10 nm in size and the layer of nanotubes up to 1 pm thick on the larger nickel particles. 

Figure 1.6 Schematic representation of (a) the diffusion-precipitation mechanism of carbon filament growth from the gas phase [32], and (b) the carbon-fiber growth mechanism proposed by OberUn et al. [33]. Important details regarding the effects of metal particle size and shape on the chemical reactions occurring at the metal-carbon interface, and thus on the nature and size of the filaments or nanotubes produced, have yet to be sorted out.

Bolton K et al (2009) Density functional theory and tight binding-based dynamical studies of carbon-metal systems of relevance to carbon nanotube growth. Nano Res 2(10) 774-782 Gavillet J et al (2001) Root-growth mechanism for single-wall carbon nanotubes. Phys Rev Lett 87(27) 275504-(4)... 

ArepaUi, S., Nikolaev, R, Holmes, W, Scott, C. D. - Diagnostic of laser-produced plume under carbon nanotube growth conditions , Appl. Phys. A 69 (1999) 1-9 Scott, C. D., ArepaUi, S., Nikolaev, P., Smalley, R. E. - Growth mechanisms for single wall carbon nanotubes in a laser ablation process , Appl. Phys. A 72 (2001) 573-580... 

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. 

The direct linking of carbon nanotubes to graphite and the continuity in synthesis, structure and properties between carbon nanotubes and vapor grown carbon fibers is reviewed by the present leaders of this area, Professor M. Endo, H. Kroto, and co-workers. Further insight into the growth mechanism is presented in the article by Colbert and Smalley. New synthesis methods leading to enhanced production... 

An alternative route to obtain NbS2-sheathed carbon nanotubes (CNT) has been proposed by Zhu et al. [71] with this sonochemical method. In this study, CNTs act as templates to produce the uniform and well-crystallized bS2 nanotubes and the formation of such nanotubes has been explained by means of multi-point nuclei site growth mechanism. 

Charlier JC, Iijima S (2001) Growth mechanisms of carbon nanotubes. Carbon Nanotubes 80 55-80. 

Figure 3.16 Different steps in the fabrication of MWNT nanoelectrode arrays, (a) metal film deposition, (b) catalyst deposition, (c) plasma-enhanced chemical vapor deposition for CNT growth, (d) dielectric encapsulation with Si02, (e) planarization with a chemical mechanical polishing to expose the ends of the carbon nanotubes, (f) electrochemical characterization. Readapted from Ref [6].

Tessonnier J-P, Su DS. Recent progress on the growth mechanism of carbon nanotubes A review. ChemSusChem. 2011 4(7) 824-847. 

A. Loiseau, X. Blase, J.C. Charlier, P. Gadelle, C. Journet, C. Laurent and A. Peigney, Synthesis methods and growth mechanisms, in Understanding Carbon Nanotubes. From Basics to Application, Lecture Notes in Physics 677, Springer, 2006. 

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