Dynamic processes at play within soft glassy materials

This work is based on an experimental analysis of the dynamical processes which occur within soft glassy materials. The first part provides measurement results of nanotracers diffusion in Laponite (a colloidal suspension) obtained by a method of fluorescence recovery (FRAP). This study shows that the diffusion is affected by the concentration of Laponite as well as the size of the tracer. A hydrodynamic model with confined diffusion allows a quantitative description of the experimental data. In a second part, an experimental study is carried out, dealing with the aging processes of glassy materials. The theoretical concept of effective temperature is probed experimentally. The effective temperature is determined using the technique of FRAP, by simultaneously measuring diffusion and convection of fluorescent probes within the aging Laponite. Contrary to some measurements found in literature, results show that the system is controlled by the bath temperature. The following study then aims at characterizing the behavior of the sheared Laponite : an experimental device is developed in this perspective, by applying an electric field to the system and thus creating local deformations. However, the observed effect appears to be too low, with relatively large uncertainties (probably linked to the complexity of the system), which impede on the significance of our results. Finally, the properties of Carbopol, a yield stress fluid, are analyzed by measuring the dynamics of capillary rise. It is shown that the surface roughness of capillary strongly affects the rise of the fluid and that the latter is controlled by the rheology of the system, and more specifically by the yield stress value.

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Source https://theses.hal.science/tel-00831474
Author Petit, Laure
Maintainer CCSD
Last Updated May 10, 2026, 19:54 (UTC)
Created May 10, 2026, 19:54 (UTC)
Identifier NNT: 2009LYO10123
Language fr
Rights https://about.hal.science/hal-authorisation-v1/
contributor Laboratoire de Physique de la Matière Condensée et Nanostructures (LPMCN) ; Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
creator Petit, Laure
date 2009-09-11T00:00:00
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harvest_source_id 3374d638-d20b-4672-ba96-a23232d55657
harvest_source_title test moissonnage SELUNE
metadata_modified 2026-03-31T00:00:00
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