Nondispersive Raman D Peak Observed in Chirally- Enriched, Single-Wall Carbon Nanotube Solutions

ORAL

Abstract

Aqueous two-phase extraction provides enriched single-wall carbon nanotubes (SWCNTs) with unprecedented chiral enrichment1. These SWCNTs possess distinctive electronic transitions that result in fingerprint optical modes. Resonant Raman spectroscopy (RRS) probes SWCNT properties such as metallicity, chirality, degree of bundling, dielectric environment inside or outside of the tube, defect density, impurity level, and the level of electron-phonon coupling. Via tunable laser sources spanning the entire visible range, we resonantly probe aqueous dispersions of single and few chirality SWCNTs. Recent findings enabled by the quality of the separated SWCNT dispersions will be highlighted. First, an under-recognized complexity in the evaluation of Raman spectra for the assignment of (n,m) population distributions2. Strong structural dependencies affect the intensity ratio of the RBM to G modes and can mislead interpretations. A second example leverages the sensitivity of Raman spectral features to symmetry breaking in the sp2 carbons, a measure of defects. A test of the depressive nature of the D or defect modes, a long-held assumption, was performed. High quality, well-separated SWCNTs enable new physics to be observed via RRS. 1Adv Mater 2014, 18, 2800 2ACS Nano 2016, 10, 525

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Presenters

  • Angela Hight Walker

    Engineering Physics, National Institute of Standards and Technology, National Institute of Standards and Technology, NIST - Natl Inst of Stds & Tech, Physical Measurements Laboratory, National Institute of Standards and Technology, Physical Measurment Division, NIST, NIST -Natl Inst of Stds & Tech, Physical Measurement Laboratory, National Institute of Standards and Technology, NIST - National Institute of Standards and Technology, National Institute of Standards and Technology (NIST), National Institute of Standards & Technology

Authors

  • Yanmei Piao

    Honeywell Aerospace

  • Jeffrey Simpson

    Engineering Physics, National Institute of Standards and Technology, Physics, Towson University, Physics, Astronomy, and GeoSciences, Towson University, Towson University, Department of Physics, Astronomy, and Geosciences, Towson University, Physics, Astronomy, and Geosciences, Towson Univ and NIST

  • Jeffrey Fagan

    National Institute of Standards and Technology, NIST - Natl Inst of Stds & Tech, NIST -Natl Inst of Stds & Tech

  • Ming Zheng

    NIST -Natl Inst of Stds & Tech

  • Angela Hight Walker

    Engineering Physics, National Institute of Standards and Technology, National Institute of Standards and Technology, NIST - Natl Inst of Stds & Tech, Physical Measurements Laboratory, National Institute of Standards and Technology, Physical Measurment Division, NIST, NIST -Natl Inst of Stds & Tech, Physical Measurement Laboratory, National Institute of Standards and Technology, NIST - National Institute of Standards and Technology, National Institute of Standards and Technology (NIST), National Institute of Standards & Technology