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Reference : UMR5221-AMEBAN-002
Workplace : MONTPELLIER
Date of publication : Tuesday, December 04, 2018
Type of Contract : FTC Scientist
Contract Period : 24 months
Expected date of employment : 1 April 2019
Proportion of work : Full time
Remuneration : from 2100 to 2300 euros per month according to experience
Desired level of education : PhD
Experience required : Indifferent
Biopolymer gels can display intriguing mechanical response when submitted to an extreme deformation. In this framework, biopolymer gels made from wheat gluten proteins may exhibit under a mechanical stress a sudden and unpredictable strong softening. Their original properties can be partially recovered after a rest time once the stress released, indicating the transient character of the bonds affected by the stress. The objective of the project is to characterize and rationalize the behavior under, and after, large deformation of elastomeric gluten gels, in order to elucidate the biochemical, physicochemical and physical mechanisms at the origin of the catastrophic response under stress. The main challenge is to unravel the respective roles of disulfides bonds and hydrogen bonds in the strain induced network breaking and the subsequent recovery at rest. The non-linear rheology of model gluten samples designed with different strategies to label and control the disulfide and the hydrogen bond exchanges will be characterized. Then, state of the art advanced soft matter techniques in addition to original spectroscopic and biochemistry approaches will be used. The multi-scale structure and dynamics of the gluten network submitted to non-linear shear stress and its recovery after large strain cycles will be investigated in situ using Small Angle Neutron Scattering, vibrational spectroscopies (Raman, Infrared), diffusing wave spectroscopy and X-ray photon correlation spectroscopy. Hence, we will be able to establish a relationship between the microscopic dynamics, the microscopic structure and the macroscopic rheology of samples during shear in the non-linear regime and after a mechanical perturbation.
-Build, perform and analyze experiences of non-linear rheology, scattering and vibrational spectroscopies.
-Communication of results via publications in scientific journals and oral communications in conferences.
PhD in Soft Matter Physics. Experiences in non-linear rheology and/or dynamic scattering would be appreciated.
The researcher will work in the Soft Matter team of the Laboratoire Charles Coulomb at Montpellier.
The project will be performed in collaboration with A. Banc, L. Ramos, L. Cipelletti from L2C (CNRS/University of Montpellier), and M-H Morel from the IATE laboratory (INRA/Supagro).
Interested applicants should send a cover letter, a complete CV with a publication list and a recommandation letter.
Starting date negociable.
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