Numerical modelling of non-ionic microgels: an overview

TL;DR

This paper reviews various numerical models of non-ionic microgels across multiple scales, emphasizing monomer-resolved approaches that capture their responsiveness and softness for understanding bulk behavior.

Contribution

It provides a comprehensive overview of multi-scale modeling methods for non-ionic microgels, highlighting the importance of microscopic details in simulations.

Findings

Monomer-resolved models effectively capture microgel properties.

Multi-scale approaches are essential for understanding bulk microgel behavior.

Realistic microscopic descriptions can inform coarse-grained models.

Abstract

Microgels are complex macromolecules. These colloid-sized polymer networks possess internal degrees of freedom and, depending on the polymer(s) they are made of, can acquire a responsiveness to variations of the environment (temperature, pH, salt concentration, etc.). Besides being valuable for many practical applications, microgels are also extremely important to tackle fundamental physics problems. As a result, these last years have seen a rapid development of protocols for the synthesis of microgels, and more and more research has been devoted to the investigation of their bulk properties. However, from a numerical standpoint the picture is more fragmented, as the inherently multi-scale nature of microgels, whose bulk behaviour crucially depends on the microscopic details, cannot be handled at a single level of coarse-graining. Here we present an overview of the methods and models that have been proposed to describe non-ionic microgels at different length-scales, from the atomistic to the single-particle level. We especially focus on monomer-resolved models, as these have the right level of details to capture the most important properties of microgels, responsiveness and softness. We suggest that these microscopic descriptions, if realistic enough, can be employed as starting points to develop the more coarse-grained representations required to investigate the behaviour of bulk suspensions.