Build-up and two-step relaxation of internal stress in jammed suspensions
| Autor: | Lavanya Mohan, Roger T. Bonnecaze, Michel Cloitre |
|---|---|
| Přispěvatelé: | Dept. of Chemical Engineering and Texas Materials Institute, University of Texas at Austin [Austin], Laboratoire Matière Molle et Chimie (MMC), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
[PHYS]Physics [physics]
Thixotropy Materials science Mechanical Engineering education Pair distribution function 02 engineering and technology Mechanics 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Mechanics of Materials 0103 physical sciences Volume fraction Stress relaxation General Materials Science Exponential decay Elasticity (economics) 010306 general physics 0210 nano-technology Material properties Magnetosphere particle motion ComputingMilieux_MISCELLANEOUS |
| Zdroj: | Journal of Rheology Journal of Rheology, American Institute of Physics, 2015, 59 (1), pp.63-84 |
| ISSN: | 0148-6055 |
| Popis: | We perform experiments on jammed suspensions of microgels with different constituent properties to determine their stress relaxation behavior on flow cessation. We observe that the stress relaxes through a two-step process: A rapid initial relaxation where internal stresses are trapped followed by a much slower decay. Trapped internal stresses are related to the solvent viscosity, particle elasticity, and volume fraction through a universal scaling. The second slower relaxation of the internal stress is characterized by a single exponential decay, which is independent of the preshear stress and relatively insensitive to the material properties of the microgel suspension. Particle-scale simulations are used to understand the microscopic mechanisms which drive the amplitude and the kinetics of the stress relaxation as well as the local particle dynamics in each regime. The rapid initial relaxation occurs through ballistic particle motion, where the number of contacts and average compression return to their static values but the asymmetry of the pair distribution function remains as a signature of the internal stress. |
| Databáze: | OpenAIRE |
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