[Zurück]

M. López Pastor, A. Domínguez-Vidal, M.J. Ayora-Cañada, Tolo Simonet, B. Lendl, M. Valcárcel:
"Separation of Single-Walled Carbon Nanotubes by Use of Ionic Liquid-Aided Capillary Electrophoresis";
Analytical Chemistry, 80 (2008), 8; S. 2672 - 2679.

This paper presents a simple, highly efficient method for analyzing single-walled carbon nanotube (SWNT) bundles based on (1) ultrasound-assisted solubilization/dispersion of SWNTs in the ionic liq. 1-butyl-3-methylimidazolium tetrafluoroborate, (2) encapsulation of the nanotubes in sodium dodecyl sulfate micelles, and (3) anal. by capillary electrophoresis. The process by which SWNTs disperse in the ionic liq. was studied by Raman spectroscopy. No degrdn. of SWNTs was obsd. under mild sonication conditions. The shape and position changes obsd. in the Raman spectral bands for the nanotubes are ascribed to debundling and interaction with the ionic liq. Sepn. of solubilized SWNTs was accomplished by using a 50 mM formic acid soln. at pH 2.0 as background electrolyte and a potential of -10 kV. Under these conditions, sepn. was completed within only 4 min. Eighteen peaks for SWNTs were identified in the anal. of com. SWNT bundles. The two types of bundles studied exhibited distinct, highly characteristic electrophoretic profiles which could be used to control SWNTs purity.