Depercolation transition of Carboxy methyl cellulose / Carbon-black gels investigated by Rheo-SAXS and Rheo-XPCS

We aim to characterize the structure and dynamics of aqueous gels made of carbon black (CB) nanoparticles stabilized by carboxy-methyl-cellulose (CMC). These gels are critical to numerous applications, including flow batteries and energy storage. SAXS and XPCS experiments will be performed both at rest and under mechanical solicitation. Here, we focus on the transition from polymer-dominated CB-CMC gels to electrically conductive colloid-dominated CB-CMC gels that we have identified via electric impedance spectroscopy and rheological measurements. In the former case, the gel is based on a continuous polymer network physically crosslinked by isolated CB aggregates, whereas in the latter, a continuous CB network spans the whole material.