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Studying the growth of single-walled carbon nanotubes by optical means
Auteur(s): Jourdain V.
Conference: GDR-I Graphene and Co (Aussois, FR, 2017-10-16)
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Voltage-activated ionic transport through single-walled carbon nanotubes
Auteur(s): Yazda K., Tahir S., Michel T., Loubet Bastien, Manghi Manoel, Bentin Jérémy, Picaud Fabien, Palmeri J., Henn F., Jourdain V.
Conference: NT17 (Belo Horizonte, BR, 2017-07-10)
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Voltage-activated transport of ions through single-walled carbon nanotubes
Auteur(s): Yazda K., Tahir S., Michel T., Loubet Bastien, Manghi Manoel, Bentin Jeremy, Picaud Fabien, Palmeri J., Henn F., Jourdain V.
(Article) Publié:
Nanoscale, vol. 9 p.11976-11986 (2017)
Ref HAL: hal-01586169_v1
DOI: 10.1039/c7nr02976d
WoS: WOS:000408435400019
Exporter : BibTex | endNote
13 Citations
Résumé: Ionic transport through single-walled carbon nanotubes (SWCNTs) is promising for many applications but remains both experimentally challenging and highly debated. Here we report ionic current measurements through microfluidic devices containing one or several SWCNTs of diameter of 1.2 to 2 nm unexpectedly showing a linear or a voltage-activated I-V dependence. Transition from an activated to a linear behavior, and stochastic fluctuations between different current levels were notably observed. For linear devices, the high conductance confirmed with different chloride salts indicates that the nanotube/water interface exhibits both a high surface charge density and flow slippage, in agreement with previous reports. In addition, the sublinear dependence of the conductance on the salt concentration points toward a charge-regulation mechanism. Theoretical modelling and computer simulations show that the voltage-activated behavior can be accounted for by the presence of local energy barriers along or at the ends of the nanotube. Raman spectroscopy reveals strain fluctuations along the tubes induced by the polymer matrix but displays insufficient doping or variations of doping to account for the apparent surface charge density and energy barriers revealed by ion transport measurements. Finally, experimental evidence points toward environment-sensitive chemical moieties at the nanotube mouths as being responsible for the energy barriers causing the activated transport of ions through SWCNTs within this diameter range.
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Unveiling the Evolutions of Nanotube Diameter Distribution during the Growth of Single-Walled Carbon Nanotubes
Auteur(s): Navas H., Picher Matthieu, Andrieux-Ledier Amandine, Fossard Frederic, Michel T., Kozawa Akinari, Maruyama Takahiro, Anglaret E., Loiseau Annick, Jourdain V.
(Article) Publié:
Acs Nano, vol. 11 p.3081-3088 (2017)
Ref HAL: hal-01516691_v1
DOI: 10.1021/acsnano.7b00077
WoS: WOS:000398014900074
Exporter : BibTex | endNote
14 Citations
Résumé: In situ and ex situ Raman measurements were used to study the dynamics of the populations of single-walled carbon nanotubes (SWCNTs) during their catalytic growth by chemical vapor deposition. Our study reveals that the nanotube diameter distribution strongly evolves during SWCNT growth but in dissimilar ways depending on the growth conditions. We notably show that high selectivity can be obtained using short or moderate growth times. High-resolution transmission electron microscopy observations support that Ostwald ripening is the key process driving these seemingly contradictory results by regulating the size distribution and lifetime of the active catalyst particles. Ostwald ripening appears as the main termination mechanism for the smallest diameter tubes, whereas carbon poisoning dominates for the largest ones. By unveiling the key concept of dynamic competition between nanotube growth and catalyst ripening, we show that time can be used as an active parameter to control the growth selectivity of carbon nanotubes and other 1D systems.
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Transport of ions and molecules inside carbon nanotubes : towards the detection of individual biomolecule
Auteur(s): Yazda K., Tahir S., Michel T., Thibaud Jean-Baptiste, Loubet Bastien, Manghi Manoel, Palmeri J., Henn F., Jourdain V.
(Affiches/Poster)
5ème Journées Scientifiques du LabEx NUMEV (Montpellier, FR), 2016-10-05
Ref HAL: hal-01950212_v1
Exporter : BibTex | endNote
Résumé: We present experimental and theoretical results for the transport of ions and molecules inside carbon nanotubes.
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Evidence of selective cation transport through sub-2 nm single-walled carbon nanotubes
Auteur(s): Yazda K., Tahir S., Michel T., Henn F., Jourdain V.
(Article) Publié:
Mrs Advances, vol. 1 p.2079-2084 (2016)
Ref HAL: hal-01928862_v1
DOI: 10.1557/adv.2016.323
WoS: WOS:000412635300009
Exporter : BibTex | endNote
Résumé: The electrophoretic transport of ions through single wall carbon nanotubes (SWCNTs) of diameters between 1.2 and 1.8 nm was studied for different monovalent chloride salts using microfluidic devices incorporating either a single or a few CNTs in parallel. The ionic conductance was found to be about one order of magnitude higher than expected from a simple electro-migration behavior without any surface effect. Importantly, the ionic conductance measured for different cations did not scale with their bulk electrophoretic mobility thus indicating a probable selective cation transport through these sub-2 nm SWCNTs. The transport of Na+ was notably found to be favored in comparison to that of Li+ and Cs+ or K+ . These results highlight the influence of steric and surface effects induced by the nano-confinement on the transport of ions through sub-2 nm SWCNTs.
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Voltage-Activated Ion Transport through Single-Walled Carbon Nanotubes
Auteur(s): Yazda K., Michel T., Tahir S., Picaud Fabien, Loubet Bastien, Manghi Manoel, Palmeri J., Henn F., Jourdain V.
Conference: MRS Fall Meeting (Boston, US, 2016-11-28)
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