HIERARCHICAL RESTRUCTURING DURING THE DRYING OF BEADS OF COLLOIDAL GEL

How gels behave under stress is of uttermost relevance for many applications; it is also scientifically important and challenging, as it involves out-of-equilibrium multiscale materials. In this proposal, we propose to investigate how the structure of colloidal gels evolves during their compaction. To do so, we propose to couple standard imaging and SAXS measurements during the drying in a controlled environment of millimetric beads of fractal colloidal gels. We will characterize how the hierarchical multiscale (from nm to um) structure of gels evolves during drying, as a function of the drying rate and initial colloid volume fraction. We will compare the scattering profiles at rest to the ones during drying to extract the relevant length scales for the compaction and use reverse Monte-Carlo strategy to extract the structure of the colloidal gel during compaction, allowing us to unveil the physical mechanisms at play.