Multi-scale dynamics of gelation of colloidal suspensions

Firstly, we will study the structure and the dynamics of colloidal gels during the diffusion of cations that cross-link the colloids. The multi-scale structure and dynamics of the gels will be characterized by static and dynamic scattering techniques (SAXS and XPCS) from short (1s) to long-time scales (several hours).
Secondly, we will study the structure and dynamics of these gels when the process of gelation is disturbed by the permeation of its solvent through the forming gel. The flow of the solvent advects the colloids towards the suspension of calcium, which are trapped when the gel is formed, and creates a gradient of concentration.
The first objective is to determine the spatial and temporal scales which are involved in the gelation of the three colloidal systems. The second objective is to understand the relationships between the structure of the gel, its kinetics of gelation and the flow of its solvent, in order to develop new ways to produce gradient hydrogels.