Carbon nanotubes bulk synthesis

Abstract. Nanocarbon materials and method of their production, developed by TMSpetsmash Ltd. (Kyiv, Ukraine), are reviewed. Multiwall carbon nanotubes with surface area 200-500 m2/g are produced in industrial scale with use of CVD method. Ethylene is used as a source of carbon and Fe-Mo-Al- mixed oxides as catalysts. Fumed silica is used as a pseudo-liquid diluent in order to decrease aggregation of nanotubes and bulk density of the products. Porous carbon nanofibers with surface area near 300-500 m2/g are produced from acetylene with use of (Fe, Co, Sn)/C/Al203-Si02 catalysts prepared mechanochemically. High surface area microporous nanocarbon materials were prepared by activation of carbon nanofibers. Effective surface area of these nanomaterials reaches 4000-6000 m2/g (by argon desorption method). Such materials are prospective for electrochemical applications. Methods of catalysts synthesis for CVD of nanocarbon materials and mechanisms of catalytic CVD are discussed. 

Coordination polymers are of special interest for nanotechnology because individual chains of these polymers could be used as molecular wires, with a number of advantages over other materials, such as carbon nanotubes, due to their easier synthesis, or higher reactivity. It is possible to modify the bulk magnetic, electronic, and optical properties of these polymers by tailoring the... 

As compared to SWCNTs, the properties of capacitors based on double-wall carbon nanotubes (DWCNTs) were not published so frequently, as pure DWCNTs are very hard to obtain. Basically, DWCNTs and multiwall carbon nanotubes (MWCNTs) have a lower surface area for EDL formation as compared to SWCNTs. On the other hand, a variety of works on capacitive performance of MWCNTs has been published, as they are relatively easily synthesized and are much cheaper than SWCNTs. As dependent on the methods of synthesis and modifications, different types of MWCNTs with different specific surface area values were obtained. Their specific capacitance values obtained in aqueous and nonaqueous electrolytes are from 10 to 100 F/g. However, they are not so high as in the case of ACs. On the other hand, one must point out that bulk capacitance is relatively high because of high bulk density of MWCNTs. Synthesis of MWCNTs is often carried out by pyrolysis of ethylene using catalysts, for example, Fe-Co. 

Park S J, Cho M S, Lim ST, Choi H J and Jhon M S (2003) Synthesis and dispersion characteristics of multi-walled carbon nanotube composites with poly(methyl methacrylate) prepared by in situ bulk polymerization, Macromol Rapid Commun 24 1070-1073. 

Nanotubular materials are important building blocks of nanotechnology, in particular, the synthesis and applications of CNTs [82, 106, 107], One application area has been the use of carbon nanotubes for molecular separations, owing to some of their unique properties. One such important property, extremely fast mass transport of molecules within carbon nanotubes associated with their low friction inner nanotube surfaces, has been demonstrated via computational and experimental studies [108,109], Furthermore, the behavior of adsorbate molecules in nano-confinement is fundamentally different than in the bulk phase, which could lead to the design of new sorbents [110],... 

---