Partenaires et organisations internationales
(Anglais)
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AT, BE, BG, CH, CY, CZ, DE, DK, ES, FI, FR, GR, HU, IE, IL, IT, LT, LV, MK, NL, NO, PL, PT, RO, SE, SK, TR, UK
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Résumé des résultats (Abstract)
(Anglais)
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Mastering interfaces is a key issue for the quality of composite and nanostructured materials. Europe is willing to consolidate its economic position in this field. To gain precious understanding of interfacial phenomena in bulk nanostructured materials and their dynamics, the lack of relevant observation methods is identified as an important bottleneck. Therefore the development of in-situ time resolved characterization methods is a clear need. This project lies within the frame of the COST Action MP0701 (Composites with novel functional and structural properties by nanoscale materials (Nano Composite Materials - NCM), with the aid of swiss large research facilities (Swiss Light Source, SLS). It aims at establishing a powerful experimental basis for the monitoring of composites integrity under transient stress (transient excitation by electromagnetic fields (emf)). In collaboration with the Spanish team of Prof J.-M. Catala-Civera from ITACA (participant of COST Action MP0701) a portable modular experimental setup has been designed and built-up, that can easily be mounted on a synchrotron or neutron beamline. It allows the simultaneous monitoring of multidimensional observables during emf exposure: - the dynamic response to transient electromagnetic field (complex permittivity) - the dynamics of the structure and crystalline phases (xray diffraction, tomography) - the kinetics of chemical reactions (EXAFS, XANES) - the dynamics of energy exchange (interphase heat flows). The advantage of using in situ time-resolved characterization techniques lies in the internal consistency of the data and in the unique ability to directly correlate the information on emf absorption events with thermal and structural changes in the specimens. During this project, the functionality of this setup has been successfully tested and used for time-resolved X-ray diffraction and microtomography experiments at the Swiss Light Source synchrotron radiation laboratory at the PSI. This type of setup was used in a parallel project within which a new type of microwave calorimetric technique with a high sensitivity to magnetic transitions was recently reported (SNF-DFG, and a student supported by COST MP0701, Short Term Scientific Mission). Further microtomography experiments are planned that could provide dynamic 3D maps of the inner geometry of the composites, i.e. the exact location of the filler particles, their sizes and shapes. In this way, the experimental prerequisites are fully met for the modelling of the thermo-electromagnetic behaviour of the particle-filled polymer composites. This pioneering set-up is opening new perspectives at the forefront of European research. It can also now serve as basis for further development. To unravel the energy transfer for instance, further efforts are planned to reach a sub ps time resolution. (planned to be proposed within the new Action MP1202 in combinaison with the swiss free electron laser national project, SwissFEL).
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