Oscillatory rheology of structured materials: mechanistic insights and modeling
| When |
May 10, 2023
from 09:30 to 10:30 |
|---|---|
| Where | R 117 |
| Attendees |
Ramya A. Koduvayur |
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Structured materials are formed by the organization of polymers, colloids, or supramolecular assembly. They exhibit rich and diverse rheological responses at large deformations by virtue of structural complexity. This talk will provide an overview of the response features of two broad classes of structured materials namely, networked systems/gels, and soft glasses, during oscillatory shear. They were characterized in terms of the type of crosslinking, presence of additional constituents, or changes in temperature/pH. Waveform analysis was utilized to interpret inherent structural mechanisms contributing to their viscoelasticity, yielding, and thixotropy, either individually or simultaneously. The specific mechanistic hypotheses unraveled include chain stretching, cage dynamics, structural kinetics, and transient fibrillar network dynamics. Novel phenomenological modifications or combinations of constitutive models were utilized to capture the distinct response features of each material system. Further, the potential of exploring Rheo-small angle neutron scattering (SANS) to test structural hypotheses will be discussed.