Videos

The Physics of Gel-like Substances on Russ Altman’s “The Future of Everything” podcast

Professor Zia talks to Russ Altman about the physics of colloids and their broad impact on cellular biology and the design of new materials.

Phase Mechanics I: How Gels Age and Coarsen

Colloidal gels change and coarsen as they age. In this video, we explain how gels form through arrested phase separation and the flattening of the energy landscape during coarsening that deepens their arrest.

Phase Mechanics II: Gel Yield is Release From Kinetic Arrest

Gels have complicated behaviors and can creep like a solid, flow like a liquid, and even resolidify. In this video, we explore the microscopic dynamics that underlie these macroscopic behaviors.

Phase Mechanics III: Gravitational Collapse and Osmotic Pressure

Colloidal gels sometimes collapse under gravity. Using our simulations, we connect this collapse to changes in the osmotic pressure that collapse the gel from within. Through the lenses of osmotic pressure and potential energy, we unify the aging, mechanical yield, and gravitational collapse of colloidal gels under the aegis of phase mechanics.

Read more from the Zia Group:

R.N. Zia*, B.J. Landrum, and W.B. Russel, “A micro-mechanical study of coarsening and rheology of colloidal gels: Cage building, cage hopping, and Smoluchowski’s ratchet.” J. Rheol., 58(5), 1121-1157 (2014) .

B.J. Landrum, W.B. Russel, and R.N. Zia*, “Delayed yield in colloidal gels: Creep, flow, and re-entrant solid regimes.” J. Rheol., 60(4), 783-807 (2016).

P. Padmanabhan and R.N. Zia*, “Gravitational collapse of colloidal gels: Non-equilibrium phase separation driven by osmotic pressure.” Soft Matter 14, 3265-3287 (2018).

L.C. Johnson, B.J Landrum and R.N. Zia*, “Yield of reversible colloidal gels during flow startup: Release from kinetic arrest.” Soft Matter (2018).