Structural and multi-scale rheophysical investigation of diphasic magneto-sensitive materials based on biopolymers.

We present a structural and a multi-scale rheophysical investigation of magneto-sensitive materials based on biopolymers, namely aqueous solutions of sodium alginate incorporating magnetic maghemite nanoparticles, functionalized with adsorbed negative citrate ions. The large alginate ionic strength impacts the structure and the rheology of these nanocomposites in zero magnetic field. In given physico-chemical conditions, the system is fluid and homogeneous on macroscopic scales while it is diphasic on microscopic ones, containing micro-droplets coming from the demixion of the system.