Internal structure and swelling behaviour of in silico microgel particles

TL;DR

This study uses computational modeling to analyze the internal structure and swelling behavior of microgel particles, revealing how their properties depend on synthesis parameters and fitting well to the fuzzy-sphere model.

Contribution

It introduces a computational method to generate realistic microgel configurations and analyzes their structural properties across different conditions.

Findings

Chain-length distribution can be analytically predicted.

Results fit well with the fuzzy-sphere model.

Structural properties vary with temperature and synthesis parameters.

Abstract

Microgels are soft colloids that, in virtue of their polymeric nature, can react to external stimuli such as temperature or pH by changing their size. The resulting swelling/deswelling transition can be exploited in fundamental research as well as for many diverse practical applications, ranging from art restoration to medicine. Such an extraordinary versatility stems from the complex internal structure of the individual microgels, each of which is a crosslinked polymer network. Here we employ a recently-introduced computational method to generate realistic microgel configurations and look at their structural properties, both in real and Fourier space, for several temperatures across the volume phase transition as a function of the crosslinker concentration and of the confining radius employed during the `in-silico' synthesis. We find that the chain-length distribution of the resulting networks can be analytically predicted by a simple theoretical argument. In addition, we find that our results are well-fitted to the fuzzy-sphere model, which correctly reproduces the density profile of the microgels under study.