Le Centre national de la recherche scientifique est un organisme public de recherche pluridisciplinaire placé sous la tutelle du ministère de l’Enseignement supérieure et de la Recherche. Créé en 1939 et dirigé par des scientifiques, il a pour mission de faire progresser la connaissance et être utile à la société dans le respect des règles d’éthique, de déontologie et d’intégrité scientifique.

Poste :
Nature has developed composite materials (e.g. plant cell walls and Arthropod exoskeleton) with complex and hierarchical organization from the nano- to the macro-scale via molecular assembly. Such materials often possess remarkable optical and/or mechanical properties by simply assembling hard and soft elements. The outstanding properties of these materials have prompted the fabrication of bio-inspired composites.
Among all methods available for the preparation of multifunctional nanostructured composite materials, Layer- by-Layer (LbL) assembly [1], is currently one of the most simple and versatile nanofabrication method [2]. Recently, we have assembled isotropic and anisotropic transparent wood-inspired nano-composite materials with mechanical properties challenging even medium quality steel (Figure 1, middle) [2],[3]. The combination of LbL assembly with grazing incidence spraying (GIS) [4-5] extends our approach toward the preparation of complex (e.g. helical) multilayer films [6] in which the composition and orientation of anisometric nano-objects like nanocelluloses can be controlled independently in each layer (Figure 1, left). These helical stacks exhibit pronounced chiroptical responses (selective interaction with circularly polarized light) probed by circular dichroism (CD) spectroscopy (Figure 1, right) and Mueller-matrix spectroscopic ellipsometry (MMSE).
The goal of this internship is to study the preparation of nanocellulose-based composite materials using different deposition methods (dipping, spray-assisted, GIS, ...) and various surface analysis techniques (ellipsometry, AFM, …) and their optical and mechanical properties. The performance of these materials will be determined by advanced optical (UV- vis spectroscopy, CD spectroscopy, and MMSE) and mechanical (nanoindentation and tensile tests) characterization tools as a function of their composition and structure, the orientation of reinforcing agents, and the experimental conditions. This work will involve the PECMAT and MIM teams at Institut Charles Sadron (Strasbourg, France) and collaborations with the CERMAV (Grenoble, France) and the LCP-A2MC (Metz, France).


Objectives
1. Fabricate and characterize nanocellulose-based composite materials with various interna structures
2. Correlate material properties (mechanical and optical) with composition and structure

References:

[1] G. Decher Science 1997, 277, 1232.
[2] R. Merindol, S. Diabang, O. Felix, T. Roland, C. Gauthier, G. Decher ACS Nano 2015, 9, 1127.
[3] R. Merindol, S. Diabang, R. Mujica, V. Le Houerou, T. Roland, C. Gauthier, G. Decher, O. Felix ACS Nano 2020, 14, 16525.
[4] R. Blell, X. Lin, T. Lindström, M. Ankerfors, M. Pauly, O. Felix, G. Decher, ACS Nano 2017, 11, 84.
[5] R. Mujica, A. Augustine, M. Pauly, V. Le Houerou, G. Decher, Y. Battie, O. Felix. Compos. Sci. Technol. 2023, 233, 109889.
[6] R. Mujica, A. Augustine, M. Pauly, Y. Battie, G. Decher,
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Le Centre national de la recherche scientifique est l’une des plus importantes institutions publiques au monde : 34 000 femmes et hommes (plus de 1 000 laboratoires et 200 métiers), en partenariat avec les universités et les grandes écoles, y font progresser les connaissances en explorant le vivant, la matière, l’Univers et le fonctionnement des sociétés humaines. Depuis plus de 80 ans, y sont développées des recherches pluri et interdisciplinaires sur tout le territoire national, en Europe et à l’international. Le lien étroit que le CNRS tisse entre ses missions de recherche et le transfert vers la société fait de lui un acteur clé de l’innovation en France et dans le monde. Le partenariat qui le lie avec les entreprises est le socle de sa politique de valorisation et les start-ups issues de ses laboratoires (près de 100 chaque année) témoignent du potentiel économique de ses travaux de recherche.

Profil echerché :
This multidisciplinary work at the frontier between chemistry, nanoscience, materials science and optics will involve thin film fabrication, structural characterization and physicochemical characterization. We are looking for a highly motivated master 2 student (M/F) having a formation in physical chemistry, chemical engineering or materials science and preferably with skills and/or interests in the following areas: materials, physical chemistry, thin layers, polymers and surfaces. The candidate (M/F) will work in a dynamic environment, in which collaboration with other team members will be encouraged. Excellent communication skills (both written and oral) in English are expected, while knowledge of French is not mandatory. Nice-to-have: experimental mindset, problem-solving skills, scientific rigor, autonomy.

Application:
Interested candidates (M/F) should provide a CV, a cover letter, a copy of their Master (L3 and M1) and/or engineering school transcripts and at least one letter of recommendation.

Conditions Particulières :
The PhD student (M/F) will be made aware of and trained on the risks inherent to his/her work environment.