Paper Number
PO24 

Session
Poster Session

Title
Dynamics of meniscus-bound particle clusters in extensional flow

Presentation Date and Time
October 12, 2022 (Wednesday) 6:30

Track / Room
Poster Session / Riverwalk A

Authors (Click on name to view author profile)

  1. Chaudhary, Sagar (University of Illinois at Urbana-Champaign, Mechanical Science and Engineering)
  2. Vaswani, Jovina (University of Pittsburgh, Chemical Engineering)
  3. Velankar, Sachin (University of Pittsburgh, Chemical Engineering)
  4. Schroeder, Charles M. (University of Illinois at Urbana-Champaign, Chemical and Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Sagar Chaudhary1, Jovina Vaswani2, Sachin Velankar2 and Charles M. Schroeder3
1Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801; 2Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15261; 3Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801

Speaker / Presenter 
Chaudhary, Sagar

Keywords
experimental methods; colloids; microscopy; suspensions

Text of Abstract
Capillary suspensions are three-phase mixtures containing a solid particulate phase, a continuous phase liquid, and a second immiscible liquid. These suspensions have a diverse array of applications in materials science including 3D printing, porous materials, and novel food formulations. Despite recent progress, the micromechanics of capillary-bound clusters in non-equilibrium flow is not well understood. Here, we study the dynamics of meniscus-bound particle clusters in extensional flow using a Stokes trap, which is an automated flow-based technique that allows for precise control of fluid flow for manipulating and studying freely suspended particle clusters. We investigate the dynamics of meniscus-bound particle clusters in extensional flow as a function of capillary number Ca, cluster composition, and particle size. We observe how clusters rearrange in the extensional flow, quantify the capillary number required for their rupture, and ask if there are steady-state configurations where particles maintain a finite separation without rupture. Cluster relaxation experiments are conducted to observe the time required for clusters to return to their original state starting from a stretched configuration after the flow is stopped. Finally, we aim to determine a critical capillary number Cacr - ?r phase diagram for meniscus-bound clusters which is analogous to the classic Grace curve for droplet breakup.