Paper Number
IN17 

Session
Flow Induced Instabilities and Non-Newtonian Fluids

Title
Structure-property relationships via recovery rheology in viscoelastic materials

Presentation Date and Time
October 22, 2019 (Tuesday) 10:40

Track / Room
Track 4 / Room 305B

Authors (Click on name to view author profile)

  1. Lee, Johnny Ching-Wei (University of Illinois at Urbana-Champaign, Chemical and Biomolecular Engineering)
  2. Weigandt, Katie M. (NIST Center for Neutron Research)
  3. Kelley, Elizabeth (NIST)
  4. Rogers, Simon A. (University of Illinois at Urbana-Champaign, Department of Chemical and Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Johnny Ching-Wei Lee1, Katie M. Weigandt2, Elizabeth Kelley2, and Simon A. Rogers1
1Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801; 2NIST Center for Neutron Research, Gaithersburg, MD 20877

Speaker / Presenter 
Lee, Johnny Ching-Wei

Text of Abstract
The recoverable strain is shown to correlate to the temporal evolution of microstructure via time-resolved small-angle neutron scattering (SANS) and dynamic shear rheology. Investigating two distinct polymeric materials of wormlike micelles and fibrin network, we demonstrate that, in addition to the nonlinear structure-property relationships, the shear and normal stress evolution is dictated by the recoverable strain. A distinct sequence of physical processes under large-amplitude oscillatory shear (LAOS) is identified that clearly contains information regarding both the steady-state flow curve and the linear-regime frequency sweep, contrary to most interpretations that LAOS responses are either distinct from, or somehow intermediate between the two cases. This work provides a physically-motivated and straightforward path to further explore the structure-property relationships of viscoelastic materials under dynamic flow conditions.