Paper Number
GG24 

Session
Rheology of Gels, Glasses and Jammed Systems

Title
Time-resolved microstructural changes in large amplitude oscillatory shear (LAOS) of model multi-component soft particle gels

Presentation Date and Time
October 11, 2022 (Tuesday) 1:30

Track / Room
Track 3 / Sheraton 5

Authors (Click on name to view author profile)

  1. Donley, Gavin J. (Georgetown University, Department of Physics)
    Donley, Gavin J. (National Institute of Stadards and Technology, Infrastructure Materials Group)
  2. Bantawa, Minaspi (University of Texas at Austin, Department of Chemical Engineering)
  3. Del Gado, Emanuela (Georgetown University, Department of Physics)

Author and Affiliation Lines (in printed abstract book)
Gavin J. Donley1,2, Minaspi Bantawa3 and Emanuela Del Gado1
1Department of Physics, Georgetown University, Washington, DC 20057; 2Infrastructure Materials Group, National Institute of Stadards and Technology, Gaithersburg, MD 20899; 3Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712

Speaker / Presenter 
Bantawa, Minaspi

Keywords
theoretical methods; computational methods; colloids; gels

Text of Abstract
Soft particulate gels can reversibly yield when sufficient deformation is applied, and the characteristics of this transition can be enhanced or limited by designing hybrid hydrogel composites. 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 of the materials. To bridge this gap, we perform a series of large amplitude oscillatory shear (LAOS) numerical measurements on model soft particulate using coarse-grained molecular dynamics simulations. We first study a particulate network with local bending stiffness and then we combine it with a second component that can provide additional crosslinking to obtain two-component networks, paying particular attention to the effect of volume fraction and composition on the macroscopic and microscopic properties. Through the sequence of physical processes (SPP) framework we define time-resolved dynamic moduli and, by tracking the changes in these moduli through the period, we can distinguish transitions in the material behavior as a function of time. This approach helps us establish the microscopic 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.