Jamming of cellulose ether solutions in porous medium

International audienceWe investigate the flow of aqueous cellulose ether solutions through a bead packing using MRI (Magnetic Resonance Imaging) and filtration measurements. We observe a rather complex behaviour dominated by jamming (clogging) and unjamming phenomena in time. With the help of several characterization techniques (laser grain sizing, dynamic light scattering, optical microscopy, rheometry) we confirm that the particular methyl(hydroxyethyl) cellulose prepared with a specific protocol, tends to form aggregates in water, even at the lowest achievable concentration. These aggregates are highly polydisperse, ranging from hundred nanometers to hundred microns in size, and are deformable. Their origin appears to be the hydrophobic links among molecules and the related local crystallization. It is suggested that these features play a key role in the observed jamming/unjamming during filtration tests