Paper Number
PO33
Session
Poster Session
Title
Time-resolved microstructural changes and macroscopic sequence of physical processes in large amplitude oscillatory shear of model soft gels
Presentation Date and Time
October 13, 2021 (Wednesday) 6:30
Track / Room
Poster Session / Ballroom 1-2-3-4
Authors
- Donley, Gavin J. (Georgetown University, Physics)
- Bantawa, Minaspi (Georgetown University, Department of Physics)
- Del Gado, Emanuela (Georgetown University)
Author and Affiliation Lines
Gavin J. Donley, Minaspi Bantawa and Emanuela Del Gado
Department of Physics, Georgetown University, Washington, DC 20057-0004
Speaker / Presenter
Donley, Gavin J.
Keywords
theoretical methods; computational methods; colloids; gels; non-Newtonian fluids
Text of Abstract
The flow and deformation behavior of soft particulate gels are incredibly useful due to their ability to reversibly yield, i.e. transition between solid-like and fluid-like behavior, when sufficient deformation is applied. While the microscopic dynamics and macroscopic rheology of these systems have been studied separately in detail, the development of direct connections between the two has been difficult, particularly with regard to the non-linear rheology. To bridge this gap, we perform a series of large amplitude oscillatory shear (LAOS) numerical measurements on model soft particulate gels at different volume fractions using molecular dynamics simulations. In the model, particles interacting with a combination of a two-body short-range attraction, and a three-body bending stiffness term spontaneously self-assemble into disordered network of soft gels at relatively low volume fractions (φ<20 %).
To capture the constitutive physics occurring in the nonlinear rheology of the gels, we utilize the sequence of physical processes (SPP) framework to define time-resolved dynamic moduli. By tracking the changes in these moduli through the period, we can distinguish transitions in the material behavior as a function of time. Our goal is to establish the microsopic origin of the non-linear rheology by connecting the changes in dynamics moduli to the corresponding microstructural changes during the deformation including the non-affine displacement of particles, and the breakage, formation, and orientation of bonds.