Dual physically crosslinked double network hydrogels with high toughness and self-healing properties

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Developing hydrogels with both toughness and self-healing is a significant challenge.
• Existing materials often compromise one property for the other.

Purpose of the Study:

• To fabricate and characterize dual physically-linked Agar/PAAc-Fe3+ double network (DN) gels.
• To investigate the synergistic effects of dual crosslinking on mechanical and self-healing properties.

Main Methods:

• Fabrication of Agar/PAAc-Fe3+ DN gels utilizing hydrogen bonding and Fe3+ coordination interactions.
• Mechanical testing including tensile strength, work of extension, and elongation at break.
• Evaluation of self-recovery and self-healing properties under various conditions (Fe3+ solution, elevated temperature, ambient conditions).

Main Results:

• The DN gels exhibited excellent mechanical properties: tensile strength of 320.7 kPa, work of extension of 1520.2 kJ m-3, and elongation at break of 1130%.
• Demonstrated rapid self-recovery (100% within 15-60 min) under different conditions.
• Showcased impressive self-healing capabilities under ambient conditions.

Conclusions:

• Dual physical crosslinking via hydrogen bonds and Fe3+ coordination effectively imparts toughness and self-healing.
• Reversible sacrificial bonds in both networks contribute to energy dissipation, enhancing mechanical and recovery performance.
• The developed Agar/PAAc-Fe3+ DN gels offer a promising platform for advanced engineered materials.