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Shear-induced deformation and interfacial jamming of solid-stabilized droplets.
1Department of Chemical and Biomolecular Engineering, University of California, Irvine, California 92697-2580, USA. mohraz@uci.edu.
Soft Matter
|April 24, 2020
Summary
Solid particles stabilize droplets under shear flow, revealing new behaviors like shape changes and earlier rupture due to particle interactions. These findings impact understanding of particle-coated droplets under stress.
Area of Science:
- Fluid dynamics
- Colloid science
- Interfacial phenomena
Background:
- Solid-stabilized emulsions and particle-laden interfaces are crucial in various industrial applications.
- Understanding droplet behavior under external stress is key to controlling emulsion stability and properties.
Purpose of the Study:
- To directly investigate the dynamics of solid-stabilized droplets under shear flow using rheo-microscopy.
- To explore the influence of weakly attractive interparticle interactions on droplet behavior and stability.
- To elucidate the formation and characteristics of anisotropic particle-coated droplets after flow cessation.
Main Methods:
- Rheo-microscopy was employed to observe droplet dynamics in shear flow.
- System involved droplets stabilized by weakly attractive particles in a continuous fluid phase.
- Particle surface coverage and interparticle interactions were key variables.
Main Results:
- Droplets exhibited unforeseen phenomena under shear, including deviations from Taylor predictions and evolution to spherocylindrical shapes.
- Particle-stabilized droplets showed earlier rupture compared to bare droplets, attributed to interfacial particle attractions.
- Long-lived anisotropic droplets formed upon flow cessation due to jammed particle networks at lower surface coverage.
Conclusions:
- Weak interparticle attractions significantly influence the rheology and stability of particle-coated droplets under shear.
- Initial particle surface coverage is critical in determining the observed phenomena.
- Findings offer insights into controlling particle-coated droplet behavior for technological applications and suggest future research directions.
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