Enhanced flow in carbon nanotubes

Majumder, Mainak; Chopra, Nitin; Andrews, Rodney; Hinds, Bruce J.

doi:10.1038/438044a

Cited by 1,557 publications

(1,157 citation statements)

References 9 publications

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“…Carbon nanotubes, in particular, are potential building blocks for nanofluidic devices, [1][2][3] where control of wetting 4 and transport properties 5 at the nanoscale is required.…”

Section: Introductionmentioning

confidence: 99%

Effect of Graphitization on the Wettability and Electrical Conductivity of CVD-Carbon Nanotubes and Films

et al. 2006

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The use of carbon nanomaterials in various applications requires precise control of their surface and bulk properties. In this paper, we present a strategy for modifying the surface chemistry, wettability, and electrical conductivity of carbon tubes and films through annealing in a vacuum. Experiments were conducted with 60-300 nm nanotubes (nanopipes), produced by noncatalytic chemical vapor deposition (CVD) in a porous alumina template, and with thin films deposited by the same technique on a glassy carbon substrate having the same structure and chemistry of the CNTs. The surface of the as-produced CVD-carbon, treated with sodium hydroxide to remove the alumina template, is hydrophilic, and the bulk electrical conductivity is lower by a factor of 20 than that of fully graphitic multiwalled nanotubes (MWNT) or bulk graphite. The bulk electrical conductivity increases to the conductivity of graphite after annealing at 2000°C in a high vacuum. The analysis of CNTs by transmission electron microscopy (TEM) and Raman spectroscopy shows the ordering of carbon accompanied by an exponential increase of the in-plane crystallite size, L a , with increasing annealing temperature. Environmental scanning electron microscopy (ESEM) was used to study the interaction of CNT with water, and contact angle measurements performed using the sessile drop method on CVDcarbon films demonstrate that the contact angle increases nearly linearly with increasing annealing temperature.

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“…Carbon nanotubes, in particular, are potential building blocks for nanofluidic devices, [1][2][3] where control of wetting 4 and transport properties 5 at the nanoscale is required.…”

Section: Introductionmentioning

confidence: 99%

Effect of Graphitization on the Wettability and Electrical Conductivity of CVD-Carbon Nanotubes and Films

et al. 2006

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“…Thus, water flux and velocity could be measured. 8,18,19 The experimental condition was simulated by applying a constant force on a layer of bulk water molecules. Consequently a pressure gradient was induced between the two ends of a SWBNNT.…”

Section: Methodsmentioning

confidence: 99%

Transport properties and induced voltage in the structure of water-filled single-walled boron-nitrogen nanotubes

Yuan

Zhao

2009

Biomicrofluidics

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Density functional theory/molecular dynamics simulations were employed to give insights into the mechanism of voltage generation based on a water-filled singlewalled boron-nitrogen nanotube ͑SWBNNT͒. Our calculations showed that ͑1͒ the transport properties of confined water in a SWBNNT are different from those of bulk water in view of configuration, the diffusion coefficient, the dipole orientation, and the density distribution, and ͑2͒ a voltage difference of several millivolts would generate between the two ends of a SWBNNT due to interactions between the water dipole chains and charge carriers in the tube. Therefore, this structure of a water-filled SWBNNT can be a promising candidate for a synthetic nanoscale power cell as well as a practical nanopower harvesting device.

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“…7 To explain this behavior, slip length with values up to tens of micrometres has been used for modifying the Hagen-Poisseuille equation in a nanotube only several nanometres in diameter. 5,6 An extremely large slip length (micrometre order) inside a very small tube (nanometre order) indicates a nearly flat velocity profile, in contrast to the Hagen-Poiseuille flow model. On the other hand, experiments have also shown an increased flow resistance in nanocapillary filling, 8,9 and the explanation of this increased resistance in nanochannel is not clear either.…”

Section: Introductionmentioning

confidence: 99%

A novel far-field nanoscopic velocimetry for nanofluidics

Kuang

Wang

2010

Lab Chip

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For the first time we have been able to measure the flow velocity profile for nanofluidics with a spatial resolution better than 70 nm. Due to the diffraction resolution barrier, traditional optical methods have so far failed in measuring the velocity profile in a nanocapillary or a closed nanochannel without an opened sidewall. A novel optical point measurement method is presented which applies stimulated emission depletion (STED) microscopy to laser induced fluorescence photobleaching anemometer (LIFPA) techniques to measure flow velocity. Herein we demonstrate this far-field nanoscopic velocimetry method by measuring the velocity profile in a nanocapillary with an inner diameter of 360 nm. The closest measuring point to the wall is about 35 nm. This method opens up a new class of functional measuring techniques for nanofluidics and for nanoscale flows from the wall.

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Enhanced flow in carbon nanotubes

Cited by 1,557 publications

References 9 publications

Effect of Graphitization on the Wettability and Electrical Conductivity of CVD-Carbon Nanotubes and Films

Effect of Graphitization on the Wettability and Electrical Conductivity of CVD-Carbon Nanotubes and Films

Transport properties and induced voltage in the structure of water-filled single-walled boron-nitrogen nanotubes

A novel far-field nanoscopic velocimetry for nanofluidics

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