H. Lange

Nanocarbon production by arc discharge in water

Abstract Carbon nanostructures (onions, nanotubes and encapsulates) were generated by arc discharge in water between pure and catalyst-doped graphite electrodes. These structures were of fine quality and crystalline morphology, similar to those formed in He arc plasma. Emission spectroscopy was performed to assess the plasma components (H, O, C and C2) and temperature values. C2 radicals were determined quantitatively, between 1015 and 1016 cm−2 depending on graphite anode composition.The temperature was between 4000 and 6500 K.

PHYSIOLOGICAL TESTING OF CARBON NANOTUBES: ARE THEY ASBESTOS-LIKE?

To determine whether carbon nanotubes can induce any significant health hazards we applied methods routinely used in the pathophysiological testing of asbestos-induced disease to show that the soot with a high content of CNTs does not induce any abnormalities of pulmonary function or measurable inflammation in guinea pigs treated with carbon nanotubes.

CARBON NANOTUBES: EXPERIMENTAL EVIDENCE FOR A NULL RISK OF SKIN IRRITATION AND ALLERGY

Fullerene soot with a high content of single-wall carbon nanotubes was tested to assess its potential biochemical activity. The results of dermatological trials did not show any signs of health hazard related to skin irritation and allergic risks.

Dispersion and diameter separation of multi-wall carbon nanotubes in aqueous solutions.

Comparative studies on dispersing of multi-wall carbon nanotubes (CNTs) using two anionic surfactants (sodium dodecyl sulphate, SDS, and sodium dodecyl benzenosulfonate, SDBS) are presented. The studies were conducted on the surfactant concentrations that were close to the critical micelle concentration (CMC). The stability of CNTs suspensions obtained for surfactant solutions at concentrations lower than the CMC was investigated. It was also found that the surfactant structure has an influence on the diameter distribution of dispersed CNTs.

Pulmonary Toxicity of 1‐D Nanocarbon Materials

Abstract 1‐D (one‐dimensional) nanocarbon materials possess unique properties. However, they could become airborne and reach the lungs. In the present study the pulmonary toxicity of nanotubes was investigated. Guinea pigs were intratracheally instilled with different nanotubes and inflammatory response was measured. The results show that both the duration of exposure and material characteristics can affect the respiratory process and induce pathological reaction in lung tissue.

Large scale continuous synthesis of carbon-encapsulated magnetic nanoparticles

Fe, Fe3C and NdC2 nanoparticles, encapsulated within carbon cages, were continuously produced during the induction thermal plasma processing of Fe14Nd2B, in the presence of methane or acetylene. The product morphology was studied by means of SEM. Further structural details were obtained from TEM, HRTEM, Raman spectroscopy and x-ray powder diffraction studies. The so-produced nanostructures have core?shell structure, with inner cavity diameters varying between 10 and 30?nm. The carbon coatings were composed of between 5 and 25 graphene layers. The carbon cages were built from sp2 carbon atoms, which protected the encapsulated nanoparticles from both oxidation and agglomeration. The plasma generated products were ferromagnetic, with maximum values of coercivity field of 600?G?s, and saturation magnetization values of up to 40?emu?g?1.

Short Communication: Fullerenes: Experimental Evidence for a Null Risk of Skin Irritation and Allergy

Abstract The results of the physiological testing are presented which show that, despite its biochemical activity, the fullerene matter does not pose any health hazard related to skin irritation and allergic risks.

An optoelectronic control of arc gap during formation of fullerenes and carbon nanotubes

An automated system for controlling the interelectrode gap of the carbon arc and positioning the plasma, constructed from commercially available components, is described. The core components of the system are the linear photodetector array, analog, and digital integrated circuits, and two direct current motors. It allows for both maintaining constant arc gap and its positioning against the optical axis of the plasma diagnostic arrangement. The method of operation is demonstrated via the production of fullerenes and carbon nanotubes. This control contrivance has been used for more than one year in bench scale with very satisfactory results. In addition, the design presented here has been found to be simple to construct from readily available components and has the merit of being quite inexpensive, too (the entire cost is under

Catalyst-free synthesis of onion-like carbon nanoparticles

2400).

Temperatures and C2 column densities in a carbon arc plasma

Abstract A one-step process for the synthesis of onion-like carbon nanoparticles is described. The process is based on a thermolysis of a NaN3-C6Cl6 mixture. The effect of buffer gas (Ar or air) on the yield, morphology, and structure of the carbon products was investigated by electron microscopy, X-ray diffraction, and Raman spectroscopy. The products contained carbon-onions, amorphous carbon nanoparticles, and NaCl. The byproducts were completely removed using a simple purification process. The formation of onion-like nanoparticles is likely caused by a shock wave, a rapid increase of pressure, during thermolysis, which induced the coalescence of phenyl radicals.