Nanostructures single-walled carbon nanotubes

In other publications single-walled carbon nanotubes were shown to promote neoplasm formation in kidneys [22, 23], Contrary to [20], other authors found that carbon nanostructures were capable of inducing reactive oxygen species (oxygen radicals) that could damage cellular structures [24-26],... 

Surface enhanced Raman spectroscopy (SERS) experiments on silver and gold nanoclusters have demonstrated large enhancement levels and field confinement of 5 nm or less for various samples such as single-walled carbon nanotubes.1 However, the locations of these conditions cannot be controlled but are instead determined by the specific nanostructures used. That is, the target molecules have... 

Fluorous chemistry, involving the use of a fluorous label for the functionalization of a substrate and a fluorous solvent for extraction of the functionalized substrate, is shown to be effective in solubilizing gold and CdSe nanoparticles in a fluorous medium, through phase transfer from an aqueous or a hydrocarbon medium. While these nanoparticles were functionalized with a fluorous thiol, single-walled carbon nanotubes and ZnO nanorods could be solubilized in a fluorous medium by reacting them with a fluorous amine. Fluorous chemistry enables the solubilization of the nanostructures in the most nonpolar liquid medium possible. 

In conclusion, we have successfully demonstrated that, by using a fluorous label and a fluorous solvent, we can affect the phase transfer of gold and CdSe nanoparticles from an aqueous or hydrocarbon medium to the fluorous phase. Single-walled carbon nanotubes and ZnO nanorods can be solubilized in a fluorous solvent after interaction with a fluorous amine. Phase transfer of the nanostructures to a fluorous solvent represents solubilization in a highly nonpolar solvent, accompanied by purification. The high nonpolarity of the fluorocarbon makes it possible to study the optical and other properties of nanostructures in a medium of very low refractive index. Since the fluorocarbon extracts only the species attached to the fluorous label, the process enables one to obtain solely one product in the pure state. We believe that fluorous chemistry may have practical utility in carrying out studies of nanostructures. 

We have analyzed the influence of the annealing temperature, structural disorder, and the frequency of a continuous excitation laser radiation Vl on the first- and the second-order Raman spectra of several nanostructured carbon materials including single-wall carbon nanotubes (SWCNT), SWCNT-polymer composites, and nanostructured single-crystalline graphites. Consideration of the high-order nonlinear effects in Raman spectra and anharmonicity of characteristic Raman bands (such as G, G, and D modes) provides important information on the vibration modes and collective (phonon-like) excitations in such ID or 2D confined systems... 

FIGURE 4.1 S Schematic illustration of different nanostructured carbons, (a) A C60 fuUerene, (b) A single-wall carbon nanotube, and (c) a multi-wall carbon nanotube. (From Kroto H.W., Heath J.R., O Brian S.C., Curl R.F., Smalley R.E., Nature, 318, 162, 1985. With permission.)... 

Recently, nanostructured carbon-based fillers such as Ceo [313,314], single-wall carbon nanotubes, carbon nanohorns (CNHs), carbon nanoballoons (CNBs), ketjenblack (KB), conductive grade and graphitized carbon black (CB) [184], graphene [348], and nanodiamonds [349] have been used to prepare PLA-based composites. These fillers enhance the crystalUza-tion ofPLLA [184,313,314].Nanocomposites incorporating fibrous MWCNTsandSWCNTs are discussed in the section on fibre-reinforced plastics (section 8.12.3). 

Carbon nanotubes are one-dimensional carbon nanostructures with tubular morphology. Depending on the number of walls present in carbon nanotubes, these are named as single-walled carbon nanotubes (SWNTs), double-walled carbon nanotubes (DWNTs), and multi-walled carbon nanotubes (MWNTs). Each of these types have slightly different properties. For example, the electrical conductivity of pure SWNT is higher than that of DWNT and MWNT. Carbon nanotubes can be synthesized by arc discharge [11], laser ablation [12], catalytic CVD [13,14], etc. 

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