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Single-walled carbon nanotubes fractionation via electrophoresis

100%

Scheibe B. , Lukaszczuk P. , Rümmeli M. H. , Kalenczuk R. J. , Borowiak-Palen E.

Polish Journal of Chemical Technology

2011

tom Vol. 13, nr 3

1-4

This work presents the influence of the sonication time on the efficiency of the metallic/semiconducting (M/S) fractionation of diazonium salt functionalized single-walled carbon nanotubes (SWCNTs) via free solution electrophoresis (FSE) method. The SWCNTs synthesized via laser ablation were purified from amorphous carbon and catalyst particles through high vacuum annealing and subsequent refluxing processes in aqua regia solutions, respectively. The purified material was divided into two batches. The SWCNTs samples were dispersed in 1% SDS solution in ultrasound bath for 2 and 12 hours. Both dispersed SWCNTs samples were functionalized with p-aminobenzoic acid diazonium salt and fractionated via free solution electrophoresis method. Afterwards, the fractionated samples were recovered, purified from surfactant/functionalities by annealing and investigated via UV-Vis-NIR optical absorption spectroscopy (OAS). The efficiency of the fractionation process was estimated through the comparison of the van Hove singularities (vHS) presented in the obtained fractions to the starting SWCNTs.

Preparation of ultra-large-scale catalysts for catalytic vapour deposition of carbon nanotubes

100%

Bachmatiuk A. , Kaleńczuk R. J. , Rümmeli M. H. , Gemming T. , Borowiak-Palen E.

Materials Science Poland

2008

tom Vol. 26, No. 1

105--111

One of the most important issues in the controlled synthesis of carbon nanotubes is finding a simple way to synthesize the catalyst nanoparticles with a controlled size. The preparation of iron nanoparticles via an organic route has been presented in the paper. The nanoparticles, of the diameter ranging between 9.5 and 31 nm, supported on magnesia, were used as a catalyst in chemical vapour deposition to produce bulk scale carbon nanotubes. Two carbon feedstocks (ethanol and cyclohexane) were examined. In the optimization process, the pyrolysis temperature was varied between 650 st.C and 850 st.C. In this simple approach, no additional carrier gas was used. Multiwalled carbon nanotubes with a very low diameter distribution (19.5-2.5 nm) were fabricated. Their composition was analysed via X-ray diffraction. The samples were characterized by the resonance Raman spectroscopy and high-resolution transmission electron microscopy.