TY - CONF A1 - Goering, Harald A1 - Maneck, Heinz-Eberhard A1 - Mach, Reinhard A1 - Knoll, Uta A1 - Oleszak, Franz A1 - Gajewski, Sven A1 - Brzezinka, Klaus-Werner T1 - Synthese von Nano-Materialien - Fullerene, Kohlenstoff-Nanoröhren, Nanopulver und Schichten T2 - Materialica 2002 ; 5. Internationale Fachmesse für Werkstoffanwendungen, Oberflächen und Product Engineering CY - München, Deutschland DA - 2002-09-30 PY - 2002 SP - 1 EP - 2 AN - OPUS4-2059 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gajewski, Sven A1 - Maneck, Heinz-Eberhard A1 - Knoll, Uta A1 - Neubert, Dietmar A1 - Dörfel, Ilona A1 - Mach, Reinhard A1 - Strauß, Birgid A1 - Friedrich, Jörg Florian T1 - Purification of single walled carbon nanotubes by thermal gas phase oxidation N2 - Single walled carbon nanotubes (SWNT) have been produced in an electric arc discharge by using a graphite rod as anode which is filled with a powder mixture of graphite and metallic catalysts like nickel and yttrium. The soot material containing approximately a third of SWNT was collected from the cathode region as a soft, voluminous material. The main by-products in this process are amorphous carbon and graphitic nanoparticles which have to be removed by an appropriate purification process. The as-produced soot material was purified by gas phase oxidation in air at 355 °C. The oxidation of amorphous carbon in air is advantageous against wet chemical methods because it is better controllable. Thermogravimetric analysis and electron microscopy were used to investigate the oxidation behavior of the different kinds of carbon. Oxidation of SWNT and amorphous carbon occurs simultaneously even at moderate temperatures, whereas amorphous carbon is more rapidly oxidized than SWNT. For optimizing the purification procedure by gas phase oxidation, kinetic studies were used to determine the oxidation time for each component in the soot at a given temperature. So it is possible to remove the amorphous carbon quantitatively with minimal losses of SWNT. But it was found that graphitic nanoparticles have the highest stability against oxidation and could therefore not be quantitatively removed by this method without the complete destruction of SWNT. Therefore, the electric arc discharge process has to be a controlled process for minimum production of graphitic nanoparticles to obtain a material with a high content of SWNT. KW - Nanotubes KW - Cathodic arc discharge KW - Amorphous carbon KW - Oxidation PY - 2003 DO - https://doi.org/10.1016/S0925-9635(02)00362-X SN - 0925-9635 VL - 12 IS - 3-7 SP - 816 EP - 820 PB - Elsevier CY - New York, NY AN - OPUS4-2516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gajewski, Sven A1 - Friedrich, Jörg F. A1 - Kühn, Gerhard A1 - Decker, Renate A1 - Retzko, Iris A1 - Dörfel, Ilona A1 - Saliwan Neumann, Romeo A1 - Maneck, Heinz-Eberhard A1 - Knoll, Uta A1 - Neubert, Dietmar A1 - Mach, Reinhard A1 - Schomäker, R. T1 - Plasmachemical Fluorination of Single Walled Carbon Nanotubes T2 - Nanomaterials und Nanotechnologies (NN 2003) CY - Crete, Greece DA - 2003-08-30 PY - 2003 AN - OPUS4-4625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -