Strong and Ultra‐tough Ionic Hydrogel Based on Hyperbranched Macro‐Cross‐linker: Influence of Topological Structure on Properties

Abstract

The application of hydrogels often suffers from their inherent limitation of poor mechanical properties. Here, a carboxyl‐functionalized and acryloyl‐terminated hyperbranched polycaprolactone (PCL) was synthesized and used as a macro‐cross‐linker to fabricate a super strong and ultra‐tough ionic hydrogel. The terminal acryloyl groups of hyperbranched PCL are chemically incorporated into the network to form covalent cross‐links, which contribute to robust networks. Meanwhile, the hydrophobic domains formed by the spontaneous aggregation of PCL chains and coordination bonds between Fe3+ and COO− groups serve as dynamic non‐covalent cross‐links, which enhance the energy dissipation ability. Especially, the influence of the hyperbranched topological structure of PCL on hydrogel properties has been well investigated, exhibiting superior strengthening and toughening effects compared to the linear one. Moreover, the hyperbranched PCL cross‐linker also endowed the ionic hydrogel with higher sensitivity than the linear one when used as a strain sensor. As a result, this well‐designed ionic hydrogel possesses high mechanical strength, superior toughness, and well ionic conductivity, exhibiting potential applications in the field of flexible strain sensors.

Fabrication of Poly(ionic liquid) Hydrogels Incorporating Liquid Metal Microgels for Enhanced Synergistic Antifouling Applications

“…Although hydrogels have garnered significant interest as an antifouling material, their inadequate mechanical properties significantly limit their application in marine antifouling. , To tackle this challenge, researchers employ various strategies to improve the mechanical properties of hydrogels, including topological hydrogels, ion-cross-linked hydrogels, double-network (DN) hydrogels, and nanoparticle composite hydrogels . Wang et al developed zwitterionic polymer-modified dual-cross-linked hydrogels by incorporating Fe 3+ to enhance the cross-linking density, the composite hydrogels demonstrated satisfactory antifouling efficacy against microalgae along with robust mechanical performance .…”