A Robust, Self-Healable, and Shape Memory Supramolecular Hydrogel by Multiple Hydrogen Bonding Interactions.

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Hydrogels are crucial in biomedical applications, but often lack robust mechanical properties and self-healing capabilities.
• Developing advanced hydrogels with tunable properties and biocompatibility is essential for next-generation biomaterials.

Purpose of the Study:

• To synthesize a versatile double-network (DN) hydrogel utilizing noncovalent hydrogen bonding interactions.
• To investigate the self-healing efficiency, shape memory ability, and mechanical strength of the developed DN hydrogel.
• To explore the potential applications of this biocompatible DN hydrogel in the biomedical field.

Main Methods:

• Synthesized DN hydrogels via a heating-cooling photopolymerization process in a single water pot.
• Incorporated agar and co-polymerized N-acryloyl glycinamide (NAGA) and N-benzylacrylamide (NBAA) monomers.
• Utilized UV-light polymerization to form poly(NAGA-co-NBAA) with strong intermolecular H-bonding and agar's sol-gel transition for molecular entanglement.

Main Results:

• Achieved a DN hydrogel with high self-healing efficiency (approx. 95%) and good shape memory properties.
• Demonstrated high mechanical strength of 1.1 MPa, attributed to the dual crosslinked network.
• Confirmed complete crosslinking via multiple hydrogen bonds and physical crosslinking of agar, avoiding toxic chemical crosslinkers.

Conclusions:

• The developed DN hydrogel exhibits excellent self-healing, shape memory, and mechanical properties due to its unique double-network structure.
• The hydrogel is entirely crosslinked by noncovalent interactions, ensuring excellent biocompatibility.
• These findings highlight the potential of this versatile DN hydrogel for extensive applications in biomedical materials.