Congratulations Dr Sarah Saïdi!

13-01-2021

Sarah Saïdi has successfully completed her PhD entitled "Multi-length scale study of the impact of fluoroelastomer addition on the PVDF structure by coupled in situ measurements"

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On Wednesday, December 16th 2020, Sarah Saïdi defended her PhD thesis in the Amphithéatre of the University of Metz 9 (France) with a 45 min oral presentation followed by about two hours of questions. Title of the thesis was "Multi-lenght scale study of the impact of fluoroelastomer addition on the PVDF structure by coupled in situ measurements".

Synopsis:

PVDF is a polymorphic semi-crystalline thermoplastic highly employed in the industry as a result of the inertia, thermostability and mechanical properties. A series of different Mw PVDF have been blended with a fluoroelastomer such as P(VDF/HFP) copolymer to enhance its mechanical properties. The complexity of the generated hierarchical PVDF/(VDF/HFP) blend nanostructure has been probed by a multi-length scale by conducting time-resolved scattering techniques (DUBBLE) coupled to Raman spectroscopy to cover the structural development from the nanometer scale to tens of nanometers as well as the meso/microscopic scales (at different thermo-mechanical conditions) on which the properties of the material depend. Furthermore, the structure characterization of the PVDF/fluoroelastomer blends has been completed by several complementary techniques such as microscopy, rheology, DSC. The combination of different analytical techniques has revealed that the PVDF crystallization mechanism remained equivalent for both the neat polymer and the corresponding PVDF blend as well as the thermal transitions associated with the structural changes. However, the immiscibility of the fluoroelastomer within the PVDF matrix at the microscale have resulted in increase of the viscosity, the delay of the crystallization as well as the suppression of shear induced crystallization of the PVDF (revealed by simultaneous SAXS/WAXS in combination with a multi-pass rheometer, MPR). Importantly, the multiple data collected has been further analysed by Multivariate data analysis (MVA) to efficiently correlate the different technique sensitivities.

Assessment committee consisted of a jury of international experts from both academic institutions and industry:  Université de Haute Alsace (France), Université de Lille (France), Université de Lorraine (France), Certech  (Belgium), Universidad de Castilla-La-Mancha (Spain), Groningen University (The Netherlands), Arkema (France).

Supervisors were Pr Patrice Bourson (Université de Lorraine, France), Dr Daniel Hermida-Merino (DUBBLE@ESRF, France) and Dr. David Chapron (Université de Lorraine, France).

Congratulations Sarah and best wishes for your future from DUBBLE Team!

Top image: From left to right: Dr. David Chapron (Université de Lorraine, France; co-supervisor), Pr Patrice Bourson (Université de Lorraine, France; supervisor), Dr Sarah Saïdi, Dr Daniel Hermida-Merino (DUBBLE@ESRF, France).