Paper Number
SC22 

Session
Suspensions, Colloids, and Granular Materials

Title
Connecting structure to bulk rheology in dense disordered solids

Presentation Date and Time
October 22, 2019 (Tuesday) 2:20

Track / Room
Track 2 / Room 304

Authors (Click on name to view author profile)

1. Galloway, Larry (University of Pennsylvania, Mechanical Engineering and Applied Mechanics)
2. Ma, Xiaoguang (University of Pennsylvania, Department of Physics and Astronomy)
3. Keim, Nathan C. (California Polytechnic State University, Department of Physics)
4. Yodh, Arjun G. (University of Pennsylvania, Department of Physics and Astronomy)
5. Jerolmack, Douglas J. (University of Pennsylvania, Department of Earth and Environmental Science)
6. Arratia, Paulo E. (University of Pennsylvania, Mechanical Engineering and Applied Mechanics)

Author and Affiliation Lines (in printed abstract book)
Larry Galloway¹, Xiaoguang Ma², Nathan C. Keim³, Arjun G. Yodh², Douglas J. Jerolmack⁴, and Paulo E. Arratia^1
1Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104; ²Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104; ³Department of Physics, California Polytechnic State University, San Luis Obispo, CA 93407; ⁴Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104

Speaker / Presenter 
Galloway, Larry

Text of Abstract
How soft materials yield is a question of fundamental interest to material engineers and rheologists alike. Often, we model complex fluids from observations of the bulk response alone. However, it may be possible to predict material response by understanding the constituent particle interactions and their arrangements. This possibility is investigated here via experiments with a custom built Interfacial Stress Rheometer and densely packed monolayers of repulsive particles. The bulk rheology (G’, G’’) is measured while simultaneously tracking the positions of up to 50,000 particles spanning the needle and the wall. Previous work has shown that yield of jammed monolayers is linked to non-affine motions of individual particle trajectories. Here, I will discuss recent findings that suggest bulk rheology of a colloidal monolayer can be related to particle motions and microstructural arrangements, which is quantified by excess entropy.