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Confinement dans les nanotubes
(33) Production(s) de l'année 2016
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Fabrication of Microfluidic Devices for the study of Ion transport through Single-Walled Carbon Nanotubes
Auteur(s): Yazda K., Roman S., Tahir S., Henn F., Jourdain V.
(Article) Publié:
Mrs Advances, vol. 1 p.2085 - 2090 (2016)
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In situ study of single-walled carbon nanotube growth in an environmental scanning electron microscope.
Auteur(s): Mehedi H-A, Ravaux J, Tahir S., Podor Renaud, Jourdain V.
(Article) Publié:
Nanotechnology, vol. 27 p.505701 (2016)
Ref HAL: hal-01624816_v1
PMID 27855127
DOI: 10.1088/0957-4484/27/50/505701
WoS: 000412645900001
Exporter : BibTex | endNote
4 Citations
Résumé: Monitoring individual single-walled carbon nanotubes (SWCNTs) during their growth is a highly sought-after goal in view of understanding the processes involved in the nucleation, elongation and termination which ultimately control the diameter and chiral selectivity. Here, we report on the first truly in situ observations of SWCNT growth in an environmental scanning electron microscope (ESEM). The CNT growth from lithographically patterned catalysts was investigated as a function of the catalyst type (Fe, Co or Ni), temperature, type of precursor (ethanol or acetylene), gas phase composition and pressure, and pretreatment conditions, and we report on the most appropriate conditions for SWCNT growth in ESEM conditions. We show that this approach allows the observation at the submicron scale of the different steps of the nanotube synthesis including the catalyst reduction, the growth and percolation of the nanotube network, and the deposition of individual nanotubes grown in the gas phase on the substrate. Despite these obvious advantages, we identified a few limitations which will need to be tackled for fully taking advantage of the approach, for instance for monitoring the growth of individual SWCNTs by ESEM, including the short lifetime of the catalyst nanoparticles, the preference for kite growth (by opposition to surface growth) and the influence of the electron beam on the nanotube growth.
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Introduction à la spectroscopie Raman
Auteur(s): Michel T.
(Séminaires)
Pole Balard, IEM, Université de Montpellier (Montpellier, FR), 2016-06-07 |
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Nickel hydroxide obtained by high-temperature two-step synthesis as an effective material for supercapacitor applications
Auteur(s): Kovalenko V.L., Kotok V. A., Sykchin A.A., Mudryi A. V., Ananchenko B. A., Burkov A., Sololvov V.A., Deabate Stefano, Mehdi Ahmad, Bantignies J.-L., Henn F.
(Article) Publié:
Journal Of Solid State Electrochemistry, vol. p. (2016)
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Aggregation Control of alpha-Sexithiophene via Isothermal Encapsulation Inside Single-Walled Carbon Nanotubes
Auteur(s): Gaufres Etienne, Tang Nathalie Y. -W., Favron Alexandre, Allard Charlotte, Lapointe Francois, Jourdain V., Tahir S., Brosseau Colin-Nadeau, Leonelli Richard, Martel Richard
(Article) Publié:
Acs Nano, vol. 10 p.10220-10226 (2016)
Ref HAL: hal-01436065_v1
DOI: 10.1021/acsnano.6b05660
WoS: WOS:000388913100051
Exporter : BibTex | endNote
14 Citations
Résumé: Liquid phase encapsulation of α-sexithiophene (6T) molecules inside individualized single-walled carbon nanotubes (SWCNTs) is investigated using Ramanimaging and spectroscopy. By taking advantage of the strong Raman response of this system, we probe the encapsulation isotherms at 30°C and 115°C using a statistical ensemble of SWCNT deposited on a Si/SiO2 substrate. Two distinct and sequential stages ofencapsulation are observed: Stage 1 is a one-dimensional (1D) aggregation of 6T alignedhead-to-tail inside the nanotube and stage 2 proceeds with the assembly of a second row, giving pairs of aligned 6Ts stacked together side-by-side. The experimental data are fitted using both Langmuir (type VI) and Ising models, in which the single-aggregate (stage 1) forms spontaneously whereas the pair-aggregate (stage 2) is endothermic in toluene with formation enthalpy of 8Hpair = 260±20 meV. Tunable Raman spectroscopy for each stage reveals a bathochromic shift of the molecular resonance of the pair-aggregate, which is consistent with strong inter-molecular coupling and suggestive of J-type aggregation. This quantitative Raman approach is sensitive to roughly 10 molecules per nanotube andprovides direct evidence of molecular entry from the nanotube ends. These insights into the encapsulation process guide the preparation of well-defined 1D molecular crystals having tailored optical properties.
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Enhancing the Infrared Response of Carbon Nanotubes From Oligo-Quaterthiophene Interactions
Auteur(s): Belhboub A., Hermet P., Alvarez L., Le Parc R., Rols Stéphane, Lopes Selvati A. C., Jousselme Bruno, Sato Y., Suenaga K., Rahmani Abdelali, Bantignies J.-L.
(Article) Publié:
The Journal Of Physical Chemistry C, vol. 120 p.28802-28807 (2016)
Ref HAL: hal-01421543_v1
DOI: 10.1021/acs.jpcc.6b09329
WoS: 000390735600047
Exporter : BibTex | endNote
9 Citations
Résumé: Infrared response on a carbon nanotube is weak because this homonuclear allotrope of carbon does not bear permanent dipoles. Here, we report the discovery of an exaltation of the infrared absorption response in single-walled carbon nanotubes from dye molecule interactions. A study performed on dimethylquaterthiophene confined into the hollow core of single-walled carbon nanotubes or π-stacked at the outer surface of the latter leads to a symmetry breaking, allowing us to probe interactions between both subsystems. The nature of these interactions is discussed taking into account the tube diameter. This new phenomenon opens a new route to detect weak vibrations thanks to a confinement effect.
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Hybrid Fibrillar Xerogels with Unusual Magnetic Properties.
Auteur(s): Boulaoued Athmane, Bantignies J.-L., Le Parc R., Goze-Bac C., Mésini Philippe, Nguyen Thi-Thanh-Tam, Al Ouahabi Abdelaziz, Lutz Pierre, Guenet Jean-Michel
(Article) Publié:
Langmuir, vol. 32 p.13193-13199 (2016)
Ref HAL: hal-01417110_v1
PMID 27951692
DOI: 10.1021/acs.langmuir.6b03572
WoS: 000389866300026
Exporter : BibTex | endNote
4 Citations
Résumé: We report on the preparation of a hybrid nanomaterial made up of 1D filaments of an antiferromagnetic self-assembling bicopper complex encapsulated in polymer nanofibrils. The encapsulation process is achieved through the heterogeneous nucleation of the growth of polymer fibrils obtained by thermoreversible gelation as shown by calorimetry experiments. Neutron scattering experiments confirm that the filaments of a bicopper complex retain their 1D character after encapsulation in the fibrils. Superconducting quantum interference device experiments show that the bicopper complex, originally in the gapped spin state in the 3D bulk mesophase, displays a gapless behavior once encapsulated. Extended absorption fine structure and infrared results further highlight the difference in the molecular arrangement of the bicopper complex between the bulk mesophase and the encapsulated state, which may account for the magnetic behavior. This material, which is largely disordered, differs totally from the usual magnetic systems where this effect is observed only on highly crystalline systems with long-range order. Also, this hybrid material is very easy to prepare from its basic constituents and can be further processed in many ways.
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