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(139) Production(s) de GENIX A.-C.
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Neutron Scattering Investigation of a Diluted Blend of Poly(ethylene oxide) in Polyethersulfone 
Auteur(s): Genix A.-C., Arbe A., Arrese-Igor S., Colmenero J., Richter D., Frick B., Deen P.P.
(Article) Publié:
The Journal Of Chemical Physics, vol. 128 p.184901 (2008)
Ref HAL: hal-00498024_v1
PMID 18532842
DOI: 10.1063/1.2918497
WoS: 000255983500057
Exporter : BibTex | endNote
14 Citations
Résumé: By using quasielastic neutron scattering (QENS) with isotopic labeling we have investigated the component dynamics in a miscible blend of polyethersulfone (PES) and poly(ethylene oxide) (PEO) with 75% content in weight of PES. Due to the large difference in the glass-transition temperatures, Tg's, of the two polymers (Tg_PEO=220 K, Tg_PES=382 K) the dynamic asymmetry in the system dramatically increases when approaching the average Tg of the blend, . For the fast (PEO) component, this leads to a behavior which hints a crossover from typical glass-forming liquidlike dynamics at high temperatures to confined dynamics close to induced by the freezing of the segmental motions of the slow PES. The features of the confined PEO motion observed by QENS are similar to those of the secondary gamma-relaxation detected for pure (semicrystalline) PEO. A neutron diffraction study of the short-range order of the homopolymers and the blend suggests that this coincidence could be due to similarities in the intermolecular packing of PEO and PES polymers.
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Anomalous relaxation of self-assembled alkyl nanodomains in high-order poly(n-alkyl methacrylates)
Auteur(s): Arbe A., Genix A.-C., Colmenero J., Richter D., Fouquet P.
(Article) Publié:
Soft Matter, vol. 4 p.1792-1795 (2008)
Texte intégral en Openaccess : 
Ref HAL: hal-00498017_v1
DOI: 10.1039/b807192f
WoS: 000260376900008
Exporter : BibTex | endNote
60 Citations
Résumé: We have exploited the selectivity of neutron scattering combined with isotopic substitution to study the structure and dynamics of poly(n-alkyl methacrylates). Our diffraction data strongly support the suggested nanosegregation of main-chains and side groups. Moreover, we have been able to separately follow the dynamics of both subsystems at a molecular scale. While the structural relaxation observed at the main-chain level is standard, for high-order members the correlations involving side groups within the alkyl nanodomains relax through an exotic logarithmic decay. In these polymers, a strong dynamic asymmetry also develops. We discuss possible theoretical frameworks for the anomalous relaxation observed.
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Neutron Scattering Investigation of the Structure and Dynamics in Poly(n-Alkyl Methacrylate)s
Auteur(s): Genix A.-C.
(Séminaires)
LPMA, CNRS - Rhodia Recherche et Technologie (Lyon, France, FR), 2008-03-06 |
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Polymer Chain Dynamics in a Random Environment : Heterogeneous Mobilities
Auteur(s): Niedzwiedz K., Monkenbusch M., Wischnewski A., Richter D., Genix A.-C., Arbe A., Colmenero J., Strauch M., Straube E.
(Article) Publié:
Physical Review Letters, vol. 98 p.168301 (2007)
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Local structure of Poly(methyl methacrylate). A combined study by Neutron Diffraction and MD-Simulation
Auteur(s): Genix A.-C.
Conference: D7 Millenium Workshop (Grenoble, FR, 2007-04-26)
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Direct Microscopic Observation of Structural Relaxations in Systems with Tunable Dynamic Asymmetry
Auteur(s): Genix A.-C.
Conference: SoftComp Workshop - Universal Aspects in Soft Matter Slow Dynamics (San Sebastian, ES, 2007-12-12)
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