Carbon nanotubes physicochemical properties

Carbon nanotubes (CNTs) as well as fullerenes are splendid gift brought to the Earth from the red giant carbon stars in the long-distant universe through the spectroscopy. Moreover, those belong to new carbon allotropes of the mesoscopic scale with well-defined structures. In particular, CNTs are considered to be the materials appropriate to realise intriguing characteristics related to the mesoscopic system based on their size and physicochemical properties. 

Similar educational opportunities abound for carbon. The diamond and graphite allotropes of carbon have been mainstays of chemistry classes for generations of students and provide a contrast between a three-dimensional structure of great hardness and a two-dimensional structure with lubricant properties, respectively. We now have what can be regarded as zero- and onedimensional counterparts - buckyballs and carbon nanotubes, respectively - with their rich diversity of structural relatives and physicochemical properties (4). These materials are being employed in a variety of nanoscale devices because of their unusual chemical, mechanical and electrical properties. 

In recent years, we have seen an explosive interest in nanomaterials, in particular in nanofibers, nanofilaments, and nanotubes of the very different chemical composition. The interest arises from the specific mechanical and physicochemical properties of these nano objects, which allow them to be used, for example, as specific adsorbents, catalyst supports, reinforcing components of composite materials, and so on. The most cited generic types of nanomaterials are carbon nanofilaments and nanotubes. Numerous methods for preparing these carbon materials are known. However, the simplest method seems to be thermal pyrolysis of various carbon contain ing precursors (e.g., carbon monoxide, saturated and unsaturated hydro carbons, etc.) in the presence of special catalysts that are typically nanosized particles of nickel, cobalt, iron metals, or their alloys with different metals. 

Carbon nanotubes are a new allotropic form of caibon and possess interesting physicochemical properties. Their chance discovery was a result of an enormous interest in fullerenes. Carbon nanotubes are built of graphene layers and can assume single- or multi-wallet structures [23,25,35]. Chemical modifications of nanotubes in both open terminated areas and on outer and inner walls create many possibilities. Prospective and present applications of nanotubes depend on their physicochemical properties, such as density, resistance to stretching and bending, thermal and electrical conductivity, field emission, as well as resistance to temperature. Good adsorption properties of nanocarbon materials contribute to their extensive practical application. 

Raffa V, Ciofani G, Vittorio O, Riggio C, Cuschieri A. Physicochemical properties affecting cellular uptake of carbon nanotubes. Nanomedicine 2010 5 89-97. 

The main objective of this chapter is to provide a snapshot of the rapidly developing nanocomposite materials based on PLA. To date, various types of nanoreinforcements such as nanoclay, cellulose nanowhiskers, ultrahne layered titanate, nanoalumina, carbon nanotubes [13-19], and so on have been used for the preparation of PLA nanocomposites. For each particular system, progress is discussed chronologically, beginning with the pioneering work. Various physicochemical characterization and improved mechanical properties are summarized. Ongoing developments and promises are also discussed. Finally, possible suitable applications and future prospect of nanocomposites based on PLA are described. 

How a single graphene sheet is rolled into the cylindrical form of a single-walled carbon nanotube (S WCNT) will determine many of the physicochemical properties, such as the conductivity (metallic or semiconducting) and the This structure-dependent physicochemical behavior is one... 

New spatial forms of carbon - fullerenes, nanotubes, nanowires and nanofibers attract significant interest since the time of their discovery due to their unique physicochemical and mechanical properties [1-3]. There are three basic methods of manufacturing of the carbon nanomaterials (CNM) - laser evaporation, electric arc process, and catalytic pyrolysis of hydrocarbons. However, the multi-stage manufacturing process is a serious disadvantage for all of them. For example, the use of organic solvents (benzol, toluene, etc.) for separation of fullerenes from graphite soot results in delay of the synthesis process and decrease in the final product quantity. Moreover, some environmental problems can arise at this. 

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