Expérimental et théorique
Cellulose nanocrystals (CNC) are captivating nanoparticles extracted from plant biomass. These naturally bio-sourced derived nanocrystals are akin to slender rod-like bio-polymers of about 10 nm in diameter and  100 nm in length with tunable surface chemistry. When dispersed in a fluid such as water, they can self-assemble into micro and meso-structures that percolate to form a rigid network called hydrogel, with nanoscale pores that restrain water. These environmentally friendly new soft materials have numerous potential applications in the fields of civil engineering, health, foodstuff, electronics and robotics. In addition, CNC hydrogels are the parent materials to produce other interesting biosourced nanomaterials such as nanopapers with interesting barrier and optical properties, nanocomposites as well as architected materials such as ice-templated or 3D printed cellular structures with relevant specific mechanical properties for structural applications. In order to be properly used in the aforementioned applications, much effort has to be provided to better understand the complex rheology of CNC hydrogels. To address this challenge, in this PhD project, we will combine simulation, theory and rheometry to provide quantitative statistical insights into the elementary nanofibre scale mechanisms governing CNC networks formation and their rheological properties under shear and compression.