Stimuli-responsive devices based on stretchable, tough, tolerant, and self-healing hydrogels are critical to fabricate soft actuators but it remains a formidable challenge to develop them. Herein, a novel strategy is demonstrated to meet this challenge by incorporating functionalized boron nitride nanosheets (nano-reinforcing domains) into poly(acrylamide-co-maleic anhydride) (soft elastin matrix) hydrogel followed by glycerol–water post-treatment. The resultant glycerol-hydrogel exhibited high stretchability (strain at break up to 2700%), outstanding tensile strength and toughness (up to 2.8 MPa and 19.3 MJ m⁻³, respectively), long-term dehydration resistance to high temperature (60 °C), and excellent anti-freezing properties at low temperature (−45 °C). Furthermore, excellent self-healing capability was demonstrated by the healing of the hydrogel after three months of storage at temperatures as low as −45 °C. By taking advantage of the outstanding dehydration resistance of the glycerol-hydrogel, dual responsive actuating devices were designed based on bilayer hydrogels to grip, release, and drive a ball under different stimuli. Thus, this work not only inspires the design and fabrication of high-performance hydrogels but also broadens their applications in soft robotics, bioactuators, and other areas.

Many living tissues possess excellent mechanical properties and self-healing ability. To mimic these living tissues, a series of novel composite hydrogels, poly(acrylic acid)/surface-modified boron nitride nanosheets (PAA/BNNS-NH2) were fabricated simply through hierarchically physical interactions: molecular-scale metal coordination interaction between –COOH of PAA and Fe3+ and nanoscale H-bond between –COOH of PAA and –NH2 of BNNS-NH2. The composite hydrogels exhibit both excellent mechanical properties (including enhanced fracture stress, elongation, toughness, Young’s modulus, and dissipated energy) and rapid healing ability without any external stimulus. Especially, the B0.5P70 (the hydrogel with BNNS concentration of 0.5 mg mL− 1, the water content of 70 wt%) exhibits a fracture stress of ~ 1311 kPa and toughness of ~ 4.7 MJ m− 3, almost ~ 3 times and ~ 8 times to B0P70, respectively. The excellent properties, combined with the simple preparation method, endow these composite hydrogels with potential applications.

Recently, self-healing properties have lately received great attention for polymeric hydrogels which enables the hydrogels to restore their structures after damage and prolong the service life of the gels. However, commonly polymeric hydrogels generally exhibit poor mechanical and self-healing properties. Herein, hydroxyl-functionalized basalt fibers (f-BF) as reinforcement and methylene bis acrylamide as the crosslinking agent were introduced into poly(acrylic acid) (PAA) hydrogels for fabrication of mechanically robust and self-healing hydrogels. The enhanced PAA hydrogel was obtained through synergistic covalent cross-linking of PAA chains and dynamic crosslinking of hydrogen bond interactions between polymeric matrix and f-BF, which endow the resultant hydrogel excellent mechanical properties and self-healing ability. The PAA/f-BF double crosslink hydrogel exhibits high tensile strength of 108 KPa and excellent toughness of 344.23 KJ.m⁻³, almost ∼6 times to PAA hydrogel. The as-prepared hydrogel possesses highly stretchable of 813 %, ∼4 times to PAA hydrogel. What’s more, the as-prepared hydrogel also has enhance self-healing ability based on tensile strength reaches up to ∼85 %. The excellent performances and simple preparation should enable the development of self-healing hydrogels for potential tissue engineering and bionic robotics applications.

2D V₂C MXene/2D g-C₃N₄ nanosheet heterojunctions was exploited in this work, which almost completely removed dye pollutants (RhB and CV) with the removal ratio of 99.5%. This work is significant for the field of wastewater treatment.