Research practical proposal* in “Ultrastrong bio-inspired nano-composite materials” at the Charles Sadron Institute in Strasbourg Description Through evolution, nature has developed composite materials (e.g. bone, wood or nacre) with complex and hierarchical organization from the nano- to the macro-scale via molecular assembly. The exceptional mechanical properties of these materials have prompted the fabrication of bio-inspired composites. Among all methods available for the preparation of multifunctional nanostructured composite materials, the Layer-by-Layer technique (LbL)[1], pioneered by the team of Prof. G. Decher, is currently one of the most widely used due to its simplicity, versatility, and nanometer scale control.[2] Recently, we have LbL-assembled transparent wood-inspired nano-composite materials with mechanical properties challenging even medium quality steel (Figure 1a-c).[3]

Figure. Electron micrograph (a) and optical photograph (b) of a hybrid LbL film composed of cellulose nanofibril and poly(vinyl amine). (c) Tensile strength of a dry film (red) and a wet film (blue). (d) Schematic of a helical 7-layer model stack with a rotation of 30° between each oriented layer. The goal of this intership is to study the preparation of new bio-inspired nano-composite materials (Figure 1d) using different LbL deposition methods (dipping, spray-assisted, ...) and various surface analysis techniques (ellipsometry, UV-vis spectroscopy, …) and their optical and mechanical properties. The mechanical performance of these materials will be determined by tensile strength measurements and advanced nanoindentation techniques as a function of their composition and structure, the orientation of reinforcing agents, and the experimental conditions. This work will involve the PECTMAT and PMTP teams at Institut Charles Sadron (Strasbourg, France). [1] G. Decher, Science 277, 1232 (1997). [2] Multilayer Thin Films: Sequential Assembly of Nanocomposite Materials, 2nd Edition (Eds: Decher, G. and Schlenoff, J. B.), Wiley-VCH: Weinheim, 2012. [3] R. Merindol, S. Diabang, O. Félix, T. Roland, C. Gauthier, G. Decher, ACS Nano, 9, 1127 (2015).

Requirements & Application We are looking for a highly motivated master student 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. Please address your application (CV, motivation letter, copy of recent grades) to Olivier Félix [[email protected]] and Vincent Le Houerou [[email protected]].

* This proposal may give rise to a Master Thesis in continuation (S4 Traineeship)