The Rheology and Flow Dynamics of Wormlike Micellar Gels
| When |
Nov 14, 2023
from 11:00 to 12:00 |
|---|---|
| Where | Salle des thèses |
| Attendees |
Ronak Gupta |
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Long-chained zwitterionic surfactants form wormlike micellar (WLM) gels in solution at room temperature. These gels are useful in a variety of applications but their rheology and flow behaviour is under-studied. We rheologically characterize the material and reveal details of its microstructure along with signatures of shear-induced fracture and banding, and then we pump these WLM gels in a capillary pipe to measure the development of velocity profiles in time. Our experiments capture flow features like strong wall slip, plug and shear layers and, in doing so, highlight the transient fluid dynamics of these gels in such flows. Finally, we report droplet detachment and filament thinning experiments with WLM gels and highlight the existence of elastocapillary regimes and eventual failure. Our work shows complex dynamics in WLM gels even in simple flows and is likely to inform applications where rheology and transient fluid dynamics of similar materials play a crucial role.