Exfoliation of single-wall carbon nanotubes in aqueous surfactant suspensions: A Raman study

Abstract

Aqueous suspensions of bundles and individual singlewall carbon nanotubes were prepared with the help of surfactants. We study the changes in the Raman spectra of the suspensions with respect to powders, and of exfoliated tubes with respect to bundles. The radial breathing modes (RBM) upshift in suspensions because of the internal pressure of the liquid. By contrast, no shift is observed in the RBM spectra after exfoliation in the suspensions. However, we demonstrate a selectivity of the exfoliation process for tubes of small diameters.

Raman spectroscopy of covalently functionalized single‐wall carbon nanotubes

“…whether the SWCNTs are present as individual tubes wrapped in a surfactant, isolated on a substrate surface, or in the form of bundles. 23 Recently, Izard et al 33 reported on an upshift of RBM wavenumbers in solubilized bundles or isolated tubes with respect to those measured in dry powders. However, in those cases where the RBM resonance profiles of individual vs bundled SWCNTs were compared, the same RBM wavenumbers have been found.…”

Effect of Water Filling on the Electronic and Vibrational Resonances of Carbon Nanotubes: Characterizing Tube Opening by Raman Spectroscopy

“…Recently, various studies reported upshifts of x vib due to environmental changes such as the interactions with surfactants that were used for the solubilization of CNTs. [15] By using a bile salt, sodium deoxycholate (DOC), to solubilize the CNTs in D 2 O, the different spectral features of empty and water-filled CNTs can be very well resolved. A 2D map of RRS spectra as a function of laser wavelength is shown in Figure 1 for two such samples.…”

Spatially Controllable DNA Condensation by a Water‐Soluble Supramolecular Hybrid of Single‐Walled Carbon Nanotubes and β‐Cyclodextrin‐Tethered Ruthenium Complexes

“…The relative intensity of Dband in the Raman spectra, which correlates with defects in SWCNT structure, [17] has no significant change owing to the treatment. From the above phenomena, we can conclude the treatment method has not damaged the SWCNT electronic structure.…”