Kirk Engineering Lab, Cherry Auditorium

Isolating the Yield Stress in Tunable Thixotropic Emulsions

Elnaz Nikoumanesh

Abstract:

Soft materials are characterized by an intricate interplay of structure, dynamics, and rheological properties, which makes it challenging to accurately predict their response to shear stress. Here, we investigate how the nature of colloidal bonds – electrostatic attractions, physical entanglement, physical repulsive attraction, and covalent attractions –modify the yield stress

and thixotropy. We investigate the critical role played by these structural bonds and their effect on linear and nonlinear deformations. Specifically, we apply our novel rheological approach – serial creep divergence (SCD) – to accurately determine the yield transition and critical stress and to reveal the physical mechanisms that underlie yielding. This comprehensive approach

provides a detailed comparison of how these materials respond to shear stress, ultimately advancing our understanding of the intricate interplay between

Lectures / Presentations