Long-Range Periodicity in Carbon Nanotube Sidewall Functionalization

Worsley, Kimberly A.; Moonoosawmy, Kevin R.; Kruse, Peter

doi:10.1021/nl0493141

Cited by 60 publications

(62 citation statements)

References 29 publications

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“…A clear periodicity of~4.6 nm was observed and the cause of the periodicity was attributed to a postulating induced reactivity. [33] The periodicity in our observation is much larger (70 vs. 4.6 nm). We suggest that the molecular origin of the periodicity observed in the NHSK might be related to the concentration gradient and the heat dissipation at the lamellar growth front.…”

contrasting

confidence: 44%

“…Very few reported CNT functionalization studies have been dedicated to determining how the functional groups arrange on the CNT surface. [33] Recently, Kruse and coworkers carefully investigated the structure of the CNTs functionalized by a Bingel reaction. [33] The authors were able to identify long range, regular patterns of the functional groups on the individual CNT surfaces using scanning tunneling microscopy techniques.…”

mentioning

confidence: 99%

“…[33] Recently, Kruse and coworkers carefully investigated the structure of the CNTs functionalized by a Bingel reaction. [33] The authors were able to identify long range, regular patterns of the functional groups on the individual CNT surfaces using scanning tunneling microscopy techniques. A clear periodicity of~4.6 nm was observed and the cause of the periodicity was attributed to a postulating induced reactivity.…”

mentioning

confidence: 99%

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Nanohybrid Shish‐Kebabs: Periodically Functionalized Carbon Nanotubes

et al. 2005

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confidence: 44%

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confidence: 99%

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Nanohybrid Shish‐Kebabs: Periodically Functionalized Carbon Nanotubes

et al. 2005

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“…We attribute the observed variation in binding energies to increased reactivity of smaller diameter SWCNTs caused by curvature-induced strain and the greater release of that strain energy on sp 3 functionalization. 16 Of course, there may also be complicating factors that give a distribution of activation energies even for a single (n,m) species, such as variations among nanotubes in the initial addend density and addition pattern, including banding, [17][18][19][20] and resulting variations in binding energies due to cooperative effects. Our findings should therefore be viewed as averages over any such distributions.…”

Section: Resultsmentioning

confidence: 99%

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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“…Various cycloaddition reactions to CNTs have been developed, including ½2 þ 1 cycloaddition of dichlorocarbene [108], nitrenes [128] and bromomalonates under Bingel reaction conditions [140], ½4 þ 2 Diels-Alder cycloaddition of o-quinodimethane performed under microwave irradiation [141], ½3 þ 2 cycloaddition of azido groups under ultraviolet (UV) irradiation [142], and azomethine ylides [143]. The 1,3-dipolar addition of azomethine ylides is particularly versatile for the functionalization of CNTs [143][144][145].…”

Section: Cycloadditionmentioning

confidence: 99%