Brush-like Interactions between Thermoresponsive Microgel Particles

TL;DR

This paper presents a model describing interactions between thermoresponsive microgel particles using a polymer brush analogy, linking microstructure to mechanical properties and enabling tailored rheology of microgel-based materials.

Contribution

It introduces a simplified microstructural model that relates the softness of microgel interactions to corona thickness, aligning well with experimental data and guiding material design.

Findings

Elastic modulus matches DWS and rheometry data

Interaction potential depends on corona thickness

Model offers design rules for microgel architecture

Abstract

Using a simplified microstructural picture we show that interactions between thermosenstive microgel particles can be described by a polymer brush like corona decorating the dense core. The softness of the potential is set by the relative thickness $L_0$ of the compliant corona with respect to the overall size of the swollen particle $R$. The elastic modulus in quenched solid phases derived from the potential is found in excellent agreement with diffusing wave spectroscopy (DWS) data and mechanical rheometry. Our model thus provides design rules for the microgel architecture and opens a route to tailor rheological properties of pasty materials.