Does Supramolecular Gelation Require an External Trigger?

Overview

Journal Gels

Date 2022 Dec 22

PMID 36547337

Authors

Ruben Van Lommel

Julie Van Hooste

Johannes Vandaele

Gert Steurs

Tom Van der Donck

Frank De Proft

Susana Rocha

Dimitrios Sakellariou

Mercedes Alonso

Wim M De Borggraeve

Affiliations

Soon will be listed here.

Abstract

The supramolecular gelation of small molecules is typically preceded by an external stimulus to trigger the self-assembly. The need for this trigger stems from the metastable nature of most supramolecular gels and can limit their applicability. Herein, we present a small urea-based molecule that spontaneously forms a stable hydrogel by simple mixing without the addition of an external trigger. Single particle tracking experiments and observations made from scanning electron microscopy indicated that triggerless gelation occurred in a similar fashion as the archetypical heat-triggered gelation. These results could stimulate the search for other supramolecular hydrogels that can be obtained by simple mixing. Furthermore, the mechanism of the heat-triggered supramolecular gelation was elucidated by a combination of molecular dynamics simulations and quantitative NMR experiments. Surprisingly, hydrogelation seemingly occurs via a stepwise self-assembly in which spherical nanoparticles mature into an entangled fibrillary network.

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