Raman spectroscopy of covalently functionalized single‐wall carbon nanotubes

Graupner, Ralf

doi:10.1002/jrs.1694

Cited by 304 publications

(261 citation statements)

References 166 publications

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“…The Raman spectrum of the solid alkylated SWCNT sample, shown in the top trace of Figure 1a, reveals an intense D band near 1300 cm -1 . As it is well known that the D-band can be induced by sp 3 sites, 11 this indicates extensive covalent functionalization of the nanotubes. To monitor thermal defunctionalization, portions of this dodecylated sample were pyrolyzed for 30 minutes at various temperatures.…”

Section: Resultsmentioning

confidence: 95%

“…Our reported spectra are baseline-corrected and normalized to the dominant G band peak near 1590 cm -1 . 11 Raman spectra of SWCNTs in aqueous suspension were measured with 671 or 740 nm excitation using model NS3 or NS2 NanoSpectralyzers (Applied NanoFluorescence). Characterization of dispersed pyrolyzed samples by absorption and fluorescence spectroscopy was performed with a model NS2 NanoSpectralyzer.…”

Section: Thermal Defunctionalization Of Dodecylatedmentioning

confidence: 99%

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Structure-Dependent Thermal Defunctionalization of Single-Walled Carbon Nanotubes

et al. 2015

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Covalent sidewall functionalization of single-walled carbon nanotubes (SWCNTs) is an important tool for tailoring their properties for research purposes and applications. In this study, SWCNT samples were first functionalized by reductive alkylation using metallic lithium and 1-iodododecane in liquid ammonia. Samples of the alkyl-functionalized SWCNTs were then pyrolyzed under an inert atmosphere at selected temperatures between 100 and 500 °C to remove the addends. The extent of defunctionalization was assessed using a combination of thermogravimetric analysis, Raman measurements of the RBM, D, and G bands, absorption spectroscopy of the first-and second-order van Hove peaks, and near-IR fluorescence spectroscopy of (n,m)-specific emission bands. These measurements all indicate a substantial dependence of defunctionalization rate on nanotube diameter, with larger diameter nanotubes showing more facile loss of addends. The effective activation energy for defunctionalization is estimated to be a factor of ~1.44 greater for 0.76 nm diameter nanotubes as compared to those with 1.24 nm diameter. The experimental findings also reveal the quantitative variation with functionalization density of the Raman D/G intensity ratio and the relative near-IR 2 fluorescence intensity. Pyrolyzed samples show spectroscopic properties that are equivalent to those of SWCNTs prior to functionalization. The strong structure dependence of defunctionalization rate suggests an approach for scalable diameter-sorting of mixed SWCNT samples.KEYWORDS: covalent functionalization; pyrolysis; dodecylation; D/G ratio; nanotube fluorescence restoration 3 Single-walled carbon nanotubes (SWCNTs) are among the most intensely studied artificial nanomaterials because of their unusual fundamental properties and promise for diverse applications. An essential tool for tailoring the interactions of SWCNTs with their environment is functionalization. 1 Such functionalization may be either noncovalent, for example with coatings of surfactants, synthetic polymers, or biopolymers; 2 or covalent, achieved through chemical reactions that link addends to sidewall carbon atoms of the nanotube. [3][4][5][6] Both noncovalent and covalent functionalization are commonly used to allow SWCNTs to be individually suspended or dissolved in liquid media. In addition, one can sometimes exploit structure-specific interactions that depend on nanotube diameter and roll-up (chiral) angle. As an example, noncovalent interactions between nanotubes and the organic polymeric dye PFO are selective enough that it can extract a subset of SWCNT structures from broadly heterogeneous as-grown samples. 7 Covalent sidewall functionalization offers another possible route to SWCNT sorting, based on structure-dependent reactivity patterns. 8,9 The main such pattern is enhanced reactivity of smaller diameter nanotubes because of their greater sp 2 bond strain. 10 Although previously unexplored, variations in reactivity with structure should also affect the process of covalent defunctio...

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Section: Resultsmentioning

confidence: 95%

Section: Thermal Defunctionalization Of Dodecylatedmentioning

confidence: 99%

Structure-Dependent Thermal Defunctionalization of Single-Walled Carbon Nanotubes

et al. 2015

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“…We took into consideration the I D /I G ratio as an indirect measure of the degree of functionalization [8,23,29].…”

Section: Ft-irmentioning

confidence: 99%

Functionalization of single-walled carbon nanotubes with optically switchable spiropyrans

Canto

Flavin

Natali

et al. 2010

Carbon

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“…The position of G mode of pristine SWCNT blue shifted from 1,580 to 1,591 cm −1 on decorating SWCNT walls with Cu nanoparticles. This blue shift indicates charge transfer between Cu nanoparticles and SWCNT bundles [24][25][26].…”

Section: Resultsmentioning

confidence: 95%

Photoluminescence from SWCNT/Cu Hybrid Nanostructure Synthesized by a Soft Chemical Route

Paul

Mitra

2012

ISRN Optics

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We report a simple wet chemical technique to coat single wall carbon nanotubes (SWCNTs) with Cu nanoparticles. The SWCNT/Cu hybrid nanostructure has been characterized using field emission scanning electron microscopy (FESEM), highresolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD) study, and Raman spectroscopy. Characteristic optical properties of the nanohybrid structure have been identified through UV-Vis and photoluminescence (PL) spectroscopy. When excited by a radiation of 400 nm wavelength, PL emission in the visible range of 480-620 nm was observed due to charge transfer. This property may be exploited in photovoltaic cells, solar energy conversion, and sensor devices.

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Raman spectroscopy of covalently functionalized single‐wall carbon nanotubes

Cited by 304 publications

References 166 publications

Structure-Dependent Thermal Defunctionalization of Single-Walled Carbon Nanotubes

Structure-Dependent Thermal Defunctionalization of Single-Walled Carbon Nanotubes

Functionalization of single-walled carbon nanotubes with optically switchable spiropyrans

Photoluminescence from SWCNT/Cu Hybrid Nanostructure Synthesized by a Soft Chemical Route

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