Rheology finds distinct glass and jamming transitions in emulsions
| Autor: | Victor Breedveld, Jianshan Liao, Cong Cao, Eric R. Weeks |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Shearing (physics)
Materials science Rheometer Dispersity Thermodynamics FOS: Physical sciences Jamming 02 engineering and technology General Chemistry Condensed Matter - Soft Condensed Matter 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Rheology 0103 physical sciences Thermal Soft Condensed Matter (cond-mat.soft) Particle size 010306 general physics 0210 nano-technology Glass transition |
| DOI: | 10.48550/arxiv.2011.11806 |
| Popis: | We study the rheology of monodisperse and bidisperse emulsions with various droplet sizes (1 $\mu$m -- 2 $\mu$m diameter). Above a critical volume fraction $\phi_c$, these systems exhibit solid-like behavior and a yield stress can be detected. Previous experiments suggest that for small thermal particles, rheology will see a glass transition at $\phi_c = \phi_g =0.58$; for large athermal systems, rheology will see a jamming transition at $\phi_c = \phi_J =0.64$. However, simulations point out that at the crossover of thermal and athermal regimes, the glass and jamming transitions may both be observed in the same sample. Here we conduct an experiment by shearing four oil-in-water emulsions with a rheometer. We observe both a glass and a jamming transition for our smaller diameter droplets, and only a jamming transition for our larger diameter droplets. The bidisperse sample behaves similarly to the small droplet sample, with two transitions observed. Our rheology data are well-fit by both the Herschel-Bulkley model and the Three Component model. Based on the fitting parameters, our raw rheological data would not collapse onto a master curve. Our results suggest that liquid-solid transitions in dispersions may not be universal, but depend on particle type. |
| Databáze: | OpenAIRE |
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