Paper Number
BA10
Session
Biological and Active Matters
Title
Controlling the microscopic dynamics and rheology of colloidal gels with active motion
Presentation Date and Time
October 15, 2018 (Monday) 3:45
Track / Room
Track 6 / Tanglewood
Authors
- Szakasits, Megan E. (University of Michigan, Chemical Engineering)
- Saud, Keara T. (University of Michigan, Materials Science and Engineering)
- Solomon, Michael J. (University of Michigan, Chemical Engineering)
Author and Affiliation Lines
Megan E. Szakasits1, Keara T. Saud2, and Michael J. Solomon1
1Chemical Engineering, University of Michigan, Ann Arbor, MI 48105; 2Materials Science and Engineering, University of Michigan, Ann Arbor, MI
Speaker / Presenter
Solomon, Michael J.
Text of Abstract
Colloidal gels are a state of soft matter with attractively bonded particles in a network. These materials have important rheological properties, such as linear elasticity and a yield stress. Here, we embed active particles in colloidal gel networks to tune the microscopic dynamics and rheology of the gel network. We activate the embedded active colloids through addition of hydrogen peroxide and characterize the dynamics and rheology of the gel network as a function of the hydrogen peroxide concentration - a fuel that drives diffusiophoretic motion of the active colloids. Active motion enhances the dynamics of the gel network, and the amount of enhancement is a function of the inputted active energy. We find that the enhancement in gel dynamics is strongly correlated with changes in the elastic modulus of the gel network. Our results demonstrate how the mechanical properties of gel networks can be tuned through varying the concentration of active particles and hydrogen peroxide concentration. Through addition and depletion of the active component, we can create gels with multi-state mechanical properties, which is useful for the industrial applications of gels such as paints and coatings, consumer products and agricultural formulations.