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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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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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FT-IR and NMR structural markers for thiazole-based γ-peptide foldamers
Auteur(s): Bonnel Clément, Legrand Baptiste, Bantignies J.-L., Petitjean Hugo, Martinez Jean, Masurier Nicolas, Maillard Ludovic T
(Article) Publié:
Organic And Biomolecular Chemistry, vol. 14 p.8664 (2016)
Ref HAL: hal-01398165_v1
DOI: 10.1039/C6OB01594H
WoS: 000384467900005
Exporter : BibTex | endNote
8 Citations
Résumé: NMR spectroscopy has been established as a potent method for the detn. of foldamer structures in soln. However, the NMR techniques could be limited by averaging, so addnl. exptl. techniques are often needed to fully endorse the folding properties of a sequence. The authors have recently demonstrated that oligo-γ-peptides composed of 4-amino(methyl)-1,3-thiazole-5-carboxylic acids (ATCs) adopt an original helical fold stabilized by hydrogen bonds forming C9 pseudocycles. The main objective of the present work is to restudy the folding of ATC oligomer 1 to identify reliable FTIR and NMR structural markers that are of value for tracking the degree of organization of ATC-based peptides.
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12/14/14-Helix Formation in 2:1 alpha/beta-Hybrid Peptides Containing Bicyclo[2.2.2]octane Ring Constraints
Auteur(s): Legrand Baptiste, Andre Christophe, Moulat Laure, Didierjean Claude, Hermet P., Bantignies J.-L., Martinez Jean, Amblard Muriel, Calmes Monique
(Article) Publié:
Chemistry - A European Journal, vol. 22 p.11986-11990 (2016)
Texte intégral en Openaccess :
Ref HAL: hal-01368422_v1
DOI: 10.1002/chem.201602746
WoS: 000382925000014
Exporter : BibTex | endNote
6 Citations
Résumé: The highly constrained b-amino acid ABOC induces different types of helices in b urea and 1:1 a/b amide oligomers. The latter can adopt 11/9- and 18/16-helical folds depending on the chain length in solution. Short peptides alternating proteinogenic a-amino acids and ABOC in a 2:1 a/b repeat pattern adopted an unprecedented and stable 12/14/14-helix. The structure was established through extensive NMR, molecular dynamics, and IR studies. While the 1:1 a-AA/ABOC helices diverged from the canonical a-helix, the helix formed by the 9-mer 2:1 a/b-peptide allowed the projection of the a-aminoacid side chains in a spatial arrangement according to the a-helix. Such a finding constitutes an important step toward the conception of functional tools that use the ABOC residue as a potent helix inducer for biological applications.
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Origin of Invariant Gel Melting Temperatures in the c-T Phase Diagram of an Organogel
Auteur(s): Christ Elliot, Blanc C., Al Ouahabi Abdelaziz, Maurin D., Le Parc R., Bantignies J.-L., Guenet Jean-Michel, Collin Dominique, Mesini Philippe J.
(Article) Publié:
Langmuir, vol. 32 p.4975-4982 (2016)
Texte intégral en Openaccess :
Ref HAL: hal-01344912_v1
DOI: 10.1021/acs.langmuir.6b00995
WoS: WOS:000376223800033
Exporter : BibTex | endNote
10 Citations
Résumé: Binary c–T phase diagrams of organogelators in solvent are frequently simplified to two domains, gel and sol, even when the melting temperatures display two distinct regimes, an increase with T and a plateau. Herein, the c–T phase diagram of an organogelator in solvent is elucidated by rheology, DSC, optical microscopy, and transmitted light intensity measurements. We evidence a miscibility gap between the organogelator and the solvent above a threshold concentration, cL. In this domain the melting or the formation of the gel becomes a monotectic transformation, which explains why the corresponding temperatures are nonvariant above cL. As shown by further studies by variable temperature FTIR and NMR, different types of H-bonds drive both the liquid–liquid phase separation and the gelation.
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Carbon Nanotubes-Epoxy Composites: The role of acid treatment in Thermal and Electrical Conductivity
Auteur(s): Metz R., Diaz-Chacon L., Aznar R., Alvarez L., Ananthakumar S., Bantignies J.-L.
(Article) Publié:
Experimental Heat Transfer, vol. p.1521-0480 (2016)
Ref HAL: hal-01340964_v1
DOI: 10.1080/08916152.2016.1161675
WoS: 000391556000005
Exporter : BibTex | endNote
4 Citations
Résumé: Wet acid oxidation treatment methods have been widely reported as an effective method to purify and oxidize the surface of industrial multi-walled carbon nanotubes (MWCNT). This work examines the use of a concentrated HNO3/H2SO4 mixture in an attempt to optimize the purification procedure of industrial MWCNT with diameter distribution statistics. It is shown that acid treatments of several hours are enough to purify the nanotubes. The electrical and thermal conductivities of epoxy composites containing 0.05-0.25 wt. % of acid-treated MWCNT has been studied. The electrical conductivity of the composites decreases by more than three orders, whereas the thermal conductivity of the same specimen increases very modestly as a function of the filler content.
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