Because of their large aspect ratio, great mechanical properties, and abundance, nanofibrils of cellulose (NFCs) are promising biosourced nanofibers for structural or functional materials. However, all the processes using NFC suspensions for the production of NFC-reinforced materials such as film casting, injection, extrusion, or compression molding, encounter several rheological problems due to the fact that the flow acts upon NFCs, inducing deformations and organisation phenomena which are likely to have an impact on the mechanical properties of the final material.
Thus, it is important to better understand and be able to model the deformation of the gels and their flow-induced nanostructures during the forming processes.
Using rheometry combined with ultrasonic velocimetry, a semi analytical multiscale rheological model was recently developed with a discrete representation of NFC systems. However, the model does not account properly for the transient elastic effects induced by the NFC deformations which is an important drawback.
Thus, in this project, an original multiscale and numerical methodology is proposed to overcome this deficiency:
The simulated mechanical responses and the spatial organizations of the gels will be compared with rheology and X-ray and light scattering experiments.
This project involved a collaboration between the 3SR lab and the CERMAV.