2020/11/24 by Cong Cao, Jianshan Liao, Victor Breedveld +2 · 7 citations
Chemical Engineering · Chemistry · Engineering · Materials Science · Physics and Astronomy · #Chemical engineering #Chemical physics #Chemistry #Composite material #Condensed matter physics #Engineering #Glass transition #Jamming #Liquid Crystal Research Advancements #Material Dynamics and Properties #Materials science #Nanotechnology #Physics #Polymer #Polymer science #Rheology #Rheology and Fluid Dynamics Studies #cond-mat.soft
paper · pdf · doi:10.1039/d0sm02097d
published in Soft Matter 17(9), 2587-2595 (Royal Society of Chemistry)
arxiv created 2020/11/24 · openalex publication_date 2021/01/01 · arxiv updated 2021/03/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the rheology of monodisperse and bidisperse emulsions with various droplet sizes (1-2 μm diameter). Above a critical volume fraction φc, 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 φc = φg ≈ 0.58; for large athermal systems, rheology will see a jamming transition at φc = φJ ≈ 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 show that liquid-solid transitions in dispersions are not universal, but depend on particle size.