Hydrogels are widely used in tissue engineering, soft robots, wearable electronics, etc. However, it remains a great challenge to develop hydrogels possessing simultaneously high strength, large stretchability, great fracture energy, and good fatigue threshold to suit different applications. Herein, a novel solvent-exchange-assisted wet-annealing strategy is proposed to prepare high performance poly(vinyl alcohol) hydrogels by extensively tuning the macromolecular chain movement and optimizing the polymer network. The reinforcing and toughening mechanisms are found to be “macromolecule crystallization and entanglement”. These hydrogels have large tensile strengths up to 11.19 ± 0.27 MPa and extremely high fracture strains of 1879 ± 10%. In addition, the fracture energy and fatigue threshold can reach as high as 25.39 ± 6.64 kJ m −2 and ≈1233 J m −2 , respectively. These superb mechanical properties compare favorably to those of other tough hydrogels, organogels, and even natural tendons and synthetic rubbers. This work provides a new and effective method to fabricate superstrong, tough, stretchable, and anti-fatigue hydrogels with potential applications in artificial tendons and ligaments.
Despite the unique properties, the hydrogels’ weak mechanical properties have severely limited their practical applications, and it remains great challenging to simultaneously enhance the strength , toughness and fracture energy of hydrogels. Herein, we develop strong yet tough polyvinyl alcohol (PVA) hydrogels via the synergy of wet-annealing and Hofmeister effect. The macromolecular chain engineered multiscale strengthening and toughening are achieved. The densified polymeric network, increased crystallinity and enhanced hydrogen bonding interaction enables the PVA hydrogels to have outstanding mechanical properties. The tensile strength , toughness and fracture energy of the resultant hydrogels can reach as high as 21.4 MPa, 182.3 MJ/m 3 and 56.8 kJ/m 2 , respectively. This study provides a new avenue to effectively tune the macromolecular chain conformation and hence improve the comprehensive mechanical properties of gel materials.
危险品化学品经营许可证（带存储）