Soutenance de Gauthier Legrand
| When |
Jul 05, 2024
from 01:30 to 04:30 |
|---|---|
| Where | Amphithéâtre Anne L'Huillier |
| Contact Name | Gauthier Legrand |
| Attendees |
Gauthier Legrand |
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Dispersions based on colloids and polymers enable the design of numerous materials, particularly for energy storage. This thesis concerns aqueous dispersions of hydrophobic soot particles, carbon black (CB), using a sodium salt of carboxymethylcellulose (CMC). CMC is a charged, semi-flexible, water-soluble polymer with hydrophobic regions along its chain, forming physical bonds with the CB particles.
We show that it is possible to form CB-CMC hydrogels over a wide range of CB and CMC concentrations. These hydrogels exhibit two radically different types of behavior on either side of a critical mass ratio between CMC and CB. Below this critical ratio, CB colloids form a percolated network stabilized by CMC, whereas, above this ratio, CB colloids act as physical cross-linkers in the CMC matrix. We report here a detailed picture of these two types of structures through linear and non-linear rheological measurements, coupled with dielectric and structural (X-ray scattering) measurements.