Structure, Dynamics, and Rheology of Realistic Gaussian-Core Fluids: Unexpected Anomalies and Their Macromolecular Origin

Weexperimentally investigate the structure, dynamics, and linearrheology of dendrimer solutions as a model system of Gaussian-corefluids and ultrasoft colloids, and compare the results with thoseobtained by the coarse-grained approach. In the overpacked regime,particles pack in a way similar to Bernal's celebrated plasticinemodel. Meanwhile, the interparticle interaction displays a counterintuitivesoftening under densification. Such behaviors result in transportproperties remarkably different from the predictions of the simpleGaussian-core model. Particularly, we find a strong coupling betweenthe rearrangement of interparticle configuration and intraparticledynamics. These unexpected observations demonstrate the decisive roleof intraparticle complexity in the structure and dynamics of ultrasoftcolloids.

Automated summary

We experimentally investigated the structure, dynamics, and linear rheology of dendrimer solutions as a model system for Gaussian-core fluids and ultrasoft colloids. We compared the results with a coarse-grained approach. Our findings revealed unexpected behaviors, such as plasticine-like particle packing in the overpacked regime and counterintuitive softening of interparticle interaction under densification. These observations highlight the crucial role of intraparticle complexity in the structure and dynamics of ultrasoft colloids.