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Propriétés Electro-optiques des Nanomatériaux 1D/2D
(18) Production(s) de l'année 2018
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H bond spring behaviour in hybrid silica under pressure
Auteur(s): Le Parc R., Freitas Vânia, Creff G., Wong Chi Man M., Cattoën Xavier, Hermet P., Ferreira Rute A.S., Carlos Luis D., Bartlett John R., Bantignies J.-L.
Conference: 11eme Forum de technologie des Hautes Pressions (Sète, FR, 2018-10-01)
Ref HAL: hal-01909394_v1
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Résumé: Bridged silsesquioxane nanomaterials exhibit original mechanical properties thanks to the association of non-covalent and covalent interactions. Thanks to in situ high pressure spectroscopic studies, achieved in diamond anvil cells, the mechanical behavior of these materials was followed as a function of pressure. Figure 1: Schematic representation of bottom-up structuring in organic-inorganic hybrid silica through self-assembling process Vibrational studies on organic models coupled to ab-initio simulations show that H bond response to pressure is strengthening. In hybrid materials the H bond shows its ability to absorb the mechanical constrains by the modulation of H bond interactions. We thus show that the rigidity yielded by the inorganic polymerization is counterbalanced by the presence of the intermolecular H bond network. The hybrid materials have therefore a reversible behavior, thanks to h bonds behaving as molecular springs. For higher pressure ranges inorganic network start to be strongly impacted in a dominant way so that an irreversible loss of long range order within the organic network is observed.In a second time, the influence of the nature of the organic substructure (thiourea versus urea link, aryl versus aliphatic core) on this spring behavior is discussed.
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Non-destructive DRIFT spectroscopy measurement of the degree of curing of industrial epoxy/silica composite buildup layers
Auteur(s): Granado Lérys, Maurin D., Kempa Stefan, Gregoriades Laurence, Brüning Frank, Fréty Nicole, Anglaret E., Bantignies J.-L.
(Article) Publié:
Polymer Testing, vol. 70 p.188 - 191 (2018)
Ref HAL: hal-01902659_v1
DOI: 10.1016/j.polymertesting.2018.07.007
WoS: 000445993600024
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3 Citations
Résumé: The degree of curing of epoxy composites and coatings is one key parameter to control the reliability of manufacturing processes, particularly in printed circuit board (PCB) manufacturing where epoxy buildup composites are partially cured before processing. We show that the reaction of curing of an industrially relevant buildup composite (epoxy-phenol reinforced with silica fillers) can be monitored by diffuse reflectance infrared Fourier transform (DRIFT) in the near-infrared range. The accuracy of DRIFT measurements is confirmed by comparison with measurements in transmission mode on reference composite samples. DRIFT is demonstrated to offer an easy and reliable measurement of the epoxy degree of curing on PCB coupons.
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Carbon nanotubes functionalized with copper Hexacyanoferrate nanoparticles for a selective extraction of cesium from liquid waste
Auteur(s): Draouil H, Alvarez L., Causse Jérémy, Flaud V., Zaïbi M, Bantignies J.-L., Oueslati M, Cambedouzou J.
(Article) Publié:
Materials And Devices, vol. 3 #2 p.0407 (2018) (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01845473_v1
DOI: 10.23647/ca.md20180407
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Résumé: Single-walled carbon nanotubes are functionalized with copper hexacyanoferrate nanoparticles for the liquid-solid extraction of cesium from liquid waste and contaminated water. The functionalization process is followed mainly by x-ray photoemission spectroscopy. Indeed, determining the chemical environment around carbon or nitrogen atoms allows to evidence the formation of covalent bounding. In addition, the signatures of iron and copper ions give information on the effective growth of hexacyanoferrate nanoparticles. Furthermore, the cesium sorption mechanism is investigated by comparing the peak intensities associated to the response of potassium and cesium ions. Finally, based on the liquid chromatography analyzes, the sorption of cesium with the functionalized carbon supports is studied. The main results of this work are the demonstration of both a good selectivity of cesium trapping and a high sorption capacity by hybrid single-walled carbon nanotubes.
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Graphene and related 2D materials: An overview of the Raman studies
Auteur(s): Paillet M., Parret R., Sauvajol J.-L., Colomban Philippe
Ouvrage: Wiley, vol. 49 (2018) 8-12Texte intégral en Openaccess :
Ref HAL: hal-01724372_v1
DOI: 10.1002/jrs.5295
WoS: WOS:000425938800001
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26 Citations
Résumé: A After a brief overview of the discovery and the Raman study of new forms of carbons (intercalated graphite, carbon fiber, fullerenes, carbon nanotubes), the invaluable contribution of late Professor M. Dresselhaus is noted and the 10 reviews and 10 contributions collected to present a picture of the present Raman investigations of graphene and related 2D materials (such as black phosphorus, MoS2) are presented. Methods for numbering the graphene layers, the effects of external perturbations (temperature, pressure, doping and magnetic field) on the phonons of graphene, characterization of the chemical and structural properties of graphene at the nanoscale level by tip-enhanced Raman spectroscopy (TERS), surface enhanced Raman spectroscopy (SERS) and hyperspectral imaging, and applications combining graphene and Raman spectroscopy are addressed.
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