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Time resolved SAXS/WAXS experiments to follow in-situ growth of organic-inorganic materials prepared by sol-gel
Auteur(s): Pichon B., Vellutini L., Wong Chi Man M., Moreau J., Pritzkow H., Finet S., Blanc C., Dieudonne-George P., Bantignies J.-L., Sauvajol J.-L.
(Affiches/Poster)
Comité d'Evaluation du LCVN (Montpellier, France, FR), 2006-02-23 |
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Etude par spectroscopie d'absorption des rayons X du dopage des fagos de nanotubes monoparois
Auteur(s): Bantignies J.-L., Aznar R., Alvarez L.
(Affiches/Poster)
GFECI 2006 (Autrans, France, FR), 2006-03-28 |
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Insertion (adsorption) dans les nanotubes de carbone
Auteur(s): Abou hamad Edy, Almairac Robert, Alvarez C., Anglaret E., Aznar R., Bantignies J.-L., Bendiab Nicolas, Cambedouzou Jean, Dragin Fabienne, Firlej L., Goze-Bac C., Michel T., Rols Stéphane, Sauvajol J.-L.
(Affiches/Poster)
Comité d'Evaluation du LCVN (Montpellier, France, FR), 2006-02-23 |
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Lamellar Bridged Silsesquioxanes: Self-Assembly through a Combination of Hydrogen Bonding and Hydrophobic Interactions
Auteur(s): J. E. Moreau Joël, Vellutini Luc, Wong Chi Man Michel, Bied Catherine, Dieudonne-George P., Bantignies J.-L., Sauvajol J.-L.
(Article) Publié:
Chemistry - A European Journal, vol. 11 p.1527-1537 (2005)
Texte intégral en Openaccess :
Ref HAL: hal-00163480_v1
PMID 15662678
DOI: 10.1002/chem.200401012
WoS: 000227262000017
Exporter : BibTex | endNote
97 Citations
Résumé: The synthesis of four bis(trialkoxysilylated) organic molecules capable of self-assembly - (EtO)3Si(CH2)3NHCONH(CH2)nNHCONH(CH2)3Si(OEt)3 (n = 9-12) - associating urea functional groups and alkylidene chains of variable length is described. These compounds behave as organogelators, forming supramolecular assemblies thanks to the intermolecular hydrogen bonding of urea groups. Whereas fluoride ion-catalysed hydrolysis in ethanol in the presence of a stoichiometric amount of water produced amorphous hybrids, acid-catalysed hydrolysis in an excess of water gave rise to the formation of crystalline lamellar hybrid materials through a self-organisation process. The structural features of these nanostructured organic/inorganic hybrids were analysed by several techniques: attenuated Fourier transformed infrared (ATR-FTIR), solid-state NMR spectroscopy (13C and 29Si), scanning and transmission electron microscopy (SEM and TEM) and powder X-ray diffraction (PXRD). The reaction conditions, the hydrophobic properties of the long alkylidene chains and the hydrogen-bonding properties of the urea groups are determining factors in the formation of these self-assembled nanostructured hybrid silicas.
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Structural ordering of self-assembled alkylene-bridged silsesquioxanes probed by X-ray diffraction experiments
Auteur(s): J. E. Moreau Joël, Vellutini Luc, Dieudonne-George P., Wong Chi Man Michel, Bantignies J.-L., Sauvajol J.-L., Bied Catherine
(Article) Publié:
Journal Of Materials Chemistry, vol. 15 p.4943-4948 (2005)
Texte intégral en Openaccess :
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Far- and Mid-Infrared of Crystalline 2,2'-Bithiophene: Ab Initio Analysis and Comparison with Infrared Response
Auteur(s): Hermet P., Bantignies J.-L., Rahmani A., Sauvajol J.-L., Johnson M. R., Serein-Spirau Françoise
(Article) Publié:
The Journal Of Physical Chemistry A, vol. 109 p.1684-1691 (2005)
Texte intégral en Openaccess :
Ref HAL: hal-00383901_v1
PMID 16833493
DOI: 10.1021/jp045519m
WoS: 000227247900025
Exporter : BibTex | endNote
35 Citations
Résumé: Infrared intramolecular vibrations and lattice modes in the crystalline phase of 2,2'-bithiophene (2T) are investigated using the direct method combined with density functional theory (DFT)-based total energy calculations. For the first time, the far- and mid-infrared responses have been calculated from the Gamma-point modes and the Born effective charge tensors of the 2T crystalline phase. The relative good agreement between the calculated and experimental infrared spectra allows us to assign the origin of the main features of the experimental spectra, which is of particular interest in the far-infrared domain. These assignments are useful for understanding all the properties of the 2T crystalline phase in which phonon-phonon and electronphonon interactions play an important role.
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Polymorphism of crystalline alpha-quaterthiophene and alpha-sexithiophene: Ab initio analysis and comparison with inelastic neutron scattering response
Auteur(s): Hermet P., Bantignies J.-L., Rahmani A., Sauvajol J.-L., Johnson M. R.
(Article) Publié:
The Journal Of Physical Chemistry A, vol. 109 p.4202-4207 (2005)
Ref HAL: hal-00505063_v1
Exporter : BibTex | endNote
Résumé: Phonons in the α-quaterthiophene (4T) and α-sexithiophene (6T) polymorph phases are investigated using the direct method combined with density functional theory (DFT)-based total energy calculations. The simulation of inelastic neutron scattering spectra (INS) on the LT and HT polymorph phases of 4T and 6T enable the corresponding spectral signatures of these materials to be identified. In particular, there are two fingerprints: (i) the low-frequency vibrational modes (frequencies lower than 200 cm(-1)) and (ii) the vibrational modes in the 600-900 cm(-1) frequency range. The good agreement with the INS experimental data allows us to assign unambiguously the origin of all features (first-order and high-order processes) of these spectra and to predict that the LT phase is the phase measured experimentally both on the 4T and 6T materials. Moreover, the broad background in the 600-1400 cm(-1) frequency range and the well-defined features which appear around 940 cm(-1) in the calculated INS spectra of 4T/HT and 6T/HT are assigned to multiphonon contributions. This multiphonon contribution at 940 cm(-1), which is absent in the 4T/LT and 6T/LT INS spectra, also constitutes a fingerprint of the HT phases. Finally, the calculated dispersion curves of the two polymorph phases of 4T and 6T are given.
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