Coupling Space-Resolved Dynamic Light Scattering and Rheometry to Investigate Heterogeneous Flow and Nonaffine Dynamics in Glassy and Jammed Soft Matter

Abstract

Understanding the relationship of microscopic dynamics to mechanical response in soft matter carries far-reaching implications for industrial applications and materials design. Light scattering coupled with rheology could help here, but conventional scattering methods lack sufficient resolution, and cannot distinguish various dynamical behaviors. Thus the authors offer a setup for rheology plus space- and time-resolved dynamic light scattering, in a geometry that allows the contributions of microscopic rearrangements to be seen. Testing on a biogel shows rearrangements in time and space similar to a stick-slip process, even when the $m\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}p\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c$ rheological response is linear.