Solvent-driven dual-network entanglement for organo-hydrogels with high strength and toughness

The development of hydrogels that simultaneously achieve high strength and good toughness remains a critical challenge in soft material science, particularly for applications in flexible electronics, soft robotics, and biomedical devices. Conventional approaches often suffer from a trade-off between mechanical robustness and functional performance. In this work, we present a novel solvent-driven dual-network entanglement strategy to fabricate a strong and tough poly (vinyl alcohol) (PVA)-based organo-hydrogel by synergistically combining isopropanol (IPA) solvent substitution to induce dense polymer chain entanglement and a sodium alginate (SA) ionic crosslinked network as a dynamic energy-dissipation phase. The resulting organo-hydrogel exhibits excellent mechanical performance with a tensile strength of 3.18 MPa and a toughness of 16.65 MJ/m 3 , representing increases of approximately 17 and 49 times that of conventional PVA hydrogels, respectively. Furthermore, the organo-hydrogel displays superior swelling resistance and long-term stability in aqueous environments, enabling reliable operation in challenging conditions such as underwater motion sensing and wearable strain detection. Morphological analyses reveal the critical role of solvent-mediated chain reorganization and dual-network interactions in achieving these properties. This work not only provides a versatile platform for designing robust gel materials but also offers fundamental insights into solvent-network interactions for advanced soft material engineering.