Preparation of Aligned Carbon Nanotubes with Prescribed Dimensions:  Template Synthesis and Sonication Cutting Approach

Jeong, Soo‐Hwan; Lee, Ok Joo; Lee, Kun‐Hong; Oh, Sang Ho; Park, Chan-Gyung

doi:10.1021/cm011620h

Cited by 73 publications

(33 citation statements)

References 30 publications

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“…We note that, as the crystallite size in the starting powder was greater than 150 µm, the preparation procedure must result in tearing of the crystallites. This process may be similar to sonication induced fragmentation of carbon nanotubes 30 .…”

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confidence: 82%

High-yield production of graphene by liquid-phase exfoliation of graphite

et al. 2008

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Graphene is at the centre of nanotechnology research. In order to fully exploit its outstanding properties, a mass production method is necessary. Two main routes are possible: large-scale growth or large-scale exfoliation. Here, we demonstrate graphene dispersions with concentrations up to ~0.01 mg/ml by dispersion and exfoliation of graphite in organic solvents such as N-methylpyrrolidone. This occurs because the energy required to exfoliate graphene is balanced by the solvent-graphene interaction for solvents whose surface energy matches that of graphene. We confirm the presence of individual graphene sheets with yields of up to 12% by mass, using absorption spectroscopy, transmission electron microscopy and electron diffraction. The absence of defects or oxides is confirmed by X-ray photoelectron, infra-red and Raman spectroscopies. We can produce conductive, semi-transparent films and conductive composites. Solution processing of graphene opens up a whole range of potential large-scale applications from device or sensor fabrication to liquid phase chemistry. Hernandez et al 2Graphene is one of the most exciting nano-materials due to the cascade of unique physical properties that have recently been demonstrated. For example, due to the details of its electronic structure, charge carriers in graphene behave as massless Dirac fermions 1 . Furthermore, novel effects such as an ambipolar field effect 2 , room temperature quantum Hall effect 3 , breakdown of the Born-Oppenheimer approximation 4 are observed. However, as was the case in the early days of nanotube and nanowire research, graphene at present still suffers from one problem, critical for its mass-scale exploitation: it cannot yet be made with high yield. The standard procedure used to make graphene is micromechanical cleavage 5 . This yields the best samples to date, with mobilities up to 200,000 cm 2 /Vs. 6 However, single layers are a negligible fraction amongst large quantities of thin graphite flakes. Furthermore, it is difficult to see how to scale up this process to mass production. Alternatively, growth of graphene is also commonly achieved by annealing SiC substrates, but these samples are in fact composed of a multitude of domains, most of them sub-micrometer, and not spatially uniform in number, or in size over larger length scales 7 . A number of works have also reported graphene growth on metal substrates 8,9 , but this would require the sample transfer to insulating substrates in order to make useful devices, either via mechanical transfer or, via solution processing.Recently, a large number of papers have described the dispersion and exfoliation of graphene oxide (GO) [10][11][12][13] . This material consists of graphene-like sheets, chemically functionalised with compounds such as hydroxyls and epoxides, which stabilise the sheets in water 14 . However, this functionalisation results in considerable disruption of the electronic structure of the graphene. In fact GO is an insulator 15 rather than a semi-metal and is conceptually differen...

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confidence: 82%

High-yield production of graphene by liquid-phase exfoliation of graphite

et al. 2008

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“…[119] Other ordered templates, such as anodic aluminum oxide (AAO) and zeolites, can also be used as the substrates for VACNT array growth. [99,120] If the catalyst is properly deposited on a flat substrate, a VACNT array can also be obtained through thermal CVD. [24,91,92] A SWCNT array was synthesized on Si wafer with the assistance of water steam as an additive in 2004.…”

Section: Vertically Aligned Cntsmentioning

confidence: 99%

Carbon Nanotube Mass Production: Principles and Processes

et al. 2011

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Our society requires new materials for a sustainable future, and carbon nanotubes (CNTs) are among the most important advanced materials. This Review describes the state-of-the-art of CNT synthesis, with a focus on their mass-production in industry. At the nanoscale, the production of CNTs involves the self-assembly of carbon atoms into a one-dimensional tubular structure. We describe how this synthesis can be achieved on the macroscopic scale in processes akin to the continuous tonne-scale mass production of chemical products in the modern chemical industry. Our overview includes discussions on processing methods for high-purity CNTs, and the handling of heat and mass transfer problems. Manufacturing strategies for agglomerated and aligned single-/multiwalled CNTs are used as examples of the engineering science of CNT production, which includes an understanding of their growth mechanism, agglomeration mechanism, reactor design, and process intensification. We aim to provide guidelines for the production and commercialization of CNTs. Although CNTs can now be produced on the tonne scale, knowledge of the growth mechanism at the atomic scale, the relationship between CNT structure and application, and scale-up of the production of CNTs with specific chirality are still inadequate. A multidisciplinary approach is a prerequisite for the sustainable development of the CNT industry.

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“…To this end, in previous work, we studied the dispersion of CNTs (SWNTs and MWNTs) with surfactant (SDS) using ultrasonic irradiation [19]. It is well known that long times or vigorous sonication can result in damage of the SWNTs or even the conversion of the SWNTs into amorphous carbon [20]. On the contrary, insufficient sonication times can result in the formation of nanotube aggregates.…”

Section: Use Of Sc-swnt As Pseudostationary Phasementioning

confidence: 99%

Surfactant‐coated single‐walled carbon nanotubes as a novel pseudostationary phase in capillary EKC

et al. 2007

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The analytical potential of the use of surfactant-coated single-walled carbon nanotubes (SC-SWNTs) as pseudostationary phase in CE is described. The pseudostationary phase shows an efficient alternative in enhancing electrochromatographic resolution of compounds which are capable of interacting with a nanotube surface, such as aromatic compounds. In general, the resolution is enhanced by increasing nanotube concentration in the buffer but the maximum amount of SWNTs that can be added to background electrolyte was found limited by compatibility with the UV/visible detection. As an alternative, a low-extension partial filling was used, consisting of the introduction into the capillary of concentrated SC-SWNT, just before the sample, with a plug length similar to the sample one. This has been showed as a reliable procedure in increasing resolution and sensitivity by sweeping phenomena. Finally, the potential of SC-SWNTs to perform chiral separations is discussed.

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Preparation of Aligned Carbon Nanotubes with Prescribed Dimensions: Template Synthesis and Sonication Cutting Approach

Cited by 73 publications

References 30 publications

High-yield production of graphene by liquid-phase exfoliation of graphite

High-yield production of graphene by liquid-phase exfoliation of graphite

Carbon Nanotube Mass Production: Principles and Processes

Surfactant‐coated single‐walled carbon nanotubes as a novel pseudostationary phase in capillary EKC

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