| Autor: |
Li H; Institute of Nanotechnology , Karlsruhe Institute of Technology , Karlsruhe 76021 , Germany., Gordeev G; Department of Physics , Freie Universität Berlin , Berlin 14195 , Germany., Garrity O; Department of Physics , Freie Universität Berlin , Berlin 14195 , Germany., Peyyety NA; Institute of Nanotechnology , Karlsruhe Institute of Technology , Karlsruhe 76021 , Germany.; Institute of Materials Science , Technische Universität Darmstadt , Darmstadt 64287 , Germany., Selvasundaram PB; Institute of Nanotechnology , Karlsruhe Institute of Technology , Karlsruhe 76021 , Germany.; Institute of Materials Science , Technische Universität Darmstadt , Darmstadt 64287 , Germany., Dehm S; Institute of Nanotechnology , Karlsruhe Institute of Technology , Karlsruhe 76021 , Germany., Krupke R; Institute of Nanotechnology , Karlsruhe Institute of Technology , Karlsruhe 76021 , Germany.; Institute of Materials Science , Technische Universität Darmstadt , Darmstadt 64287 , Germany., Cambré S; Physics Department , University of Antwerp , Antwerp 2020 , Belgium., Wenseleers W; Physics Department , University of Antwerp , Antwerp 2020 , Belgium., Reich S; Department of Physics , Freie Universität Berlin , Berlin 14195 , Germany., Zheng M; Materials Science and Engineering Division , National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States., Fagan JA; Materials Science and Engineering Division , National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States., Flavel BS; Institute of Nanotechnology , Karlsruhe Institute of Technology , Karlsruhe 76021 , Germany. |
| Abstrakt: |
The enantiomer-level isolation of single-walled carbon nanotubes (SWCNTs) in high concentration and with high purity for nanotubes greater than 1.1 nm in diameter is demonstrated using a two-stage aqueous two-phase extraction (ATPE) technique. In total, five different nanotube species of ∼1.41 nm diameter are isolated, including both metallics and semiconductors. We characterize these populations by absorbance spectroscopy, circular dichroism spectroscopy, resonance Raman spectroscopy, and photoluminescence mapping, revealing and substantiating mod-dependent optical dependencies. Using knowledge of the competitive adsorption of surfactants to the SWCNTs that controls partitioning within the ATPE separation, we describe an advanced acid addition methodology that enables the fine control of the separation of these select nanotubes. Furthermore, we show that endohedral filling is a previously unrecognized but important factor to ensure a homogeneous starting material and further enhance the separation yield, with the best results for alkane-filled SWCNTs, followed by empty SWCNTs, with the intrinsic inhomogeneity of water-filled SWCNTs causing them to be worse for separations. Lastly, we demonstrate the potential use of these nanotubes in field-effect transistors. |
