Understanding Polymer-Colloid Gels: A Solvent Perspective Using Low-Field NMR

TL;DR

This study utilizes low-field NMR relaxometry to analyze water dynamics in polymer-colloid hydrogels, revealing correlations between NMR signals, microstructure, and phase transitions across various temperatures.

Contribution

It demonstrates that solvent-focused low-field NMR relaxometry effectively probes hydrogel microstructure and detects phase transitions and aging, offering a valuable tool for soft matter research.

Findings

NMR relaxometry correlates with rheological behavior.

Detection of phase transitions and aging in hydrogels.

Water dynamics vary with temperature and formulation.

Abstract

The present work emphasizes the relevance of low-field NMR relaxometry to investigate colloid-polymer hydrogels by probing water dynamics across a wide range of formulations between $\rm 10^{\circ}C$ and $\rm 80^{\circ}C$. By examining the temperature dependence of the transverse relaxation time $T_2$, we demonstrate a clear link between the NMR response and the rheological behavior of the hydrogels. In particular, we show that NMR relaxometry targeting the solvent provides reliable insights into the hydrogel microstructure and allows the detection of phase transitions and aging processes. Our findings suggest that this solvent-focused technique could greatly benefit the soft matter community, complementing other experimental methods in the study of gels.