Microstructure in Gelling Systems

Author Last Name: 
Eric Furst
Report Type: 
Research Area: 
Wet Systems
Publication Year: 
Publication Month: 
United States

The rheology of colloidal gels arises from how the ramified network structure responds to

an applied stress. Stress transmission is controlled by the topology of the microstructure

and the nature of the interparticle “bonds” between colloids. Thus, to deform a gel, these

bonds must stretch to accommodate extension and compression of the microstructure.

This project focused on developing and refining a model experimental system to directly

and quantitatively measure gels over multiple lengthscales, including the “bond”

mechanics, microstructure and bulk rheology. This work was performed in close

collaboration with Professor Michael Solomon, University of Michigan. This report

summarizes the development of the model system to achieve individual bond rupture

measurements and the validation of bond rupture measurements by a dynamical model of

bond rupture. We conclude with a comparison of the experimental gel modulus to the

modulus predicted by current theory and an energy balance model.