Tunable and Self-Healing Properties of Polysaccharide-Based Hydrogels through Polymer Architecture Modulation

摘要

Hydrogel-based devices have attracted tremendous attention due to their potential applications in sensors and soft actuators. However, it is still a challenge for hydrogel-based devices to be integrated with high conductivity, sustainability, reusability, extraordinary mechanical strength, and high stretchability. Herein, a multiple-network hydrogel has been developed via a simple one-pot method based on poly(vinyl alcohol) (PVA), Gleditsia sinensis polysaccharide gum (GSG), and 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO)-oxidated nanocellulose (TOCNF), using borax as a cross-linker. The optimal hydrogel (PGB-TOCNF) exhibited high mechanical strength (378 kPa), stretchability (548% breaking elongation), and compressibility (92% compression strain), as well as considerable conductive behavior. Importantly, the unique self-healing, reformable, and injectable properties of the polysaccharide-based hydrogel could be due to dynamic and reversible borate ester bonds and could also be locked by the formation of PVA nanocrystals during the freezing–thawing process. This work broadens the avenue for designing polysaccharide-derived hydrogels for applications in sensors, wearable electronics, and soft robots.