NIR-Triggered Rapid Shape Memory PAM-GO-Gelatin Hydrogels with High Mechanical Strength

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials

Background:

• Shape memory hydrogels are advanced materials capable of recovering their original shape when subjected to a stimulus.
• Developing hydrogels with efficient shape recovery, high mechanical strength, and controlled actuation is crucial for various applications.

Purpose of the Study:

• To synthesize and characterize a novel shape memory hydrogel with a high water content.
• To investigate the role of graphene oxide (GO) in enabling near-infrared (NIR) triggered shape recovery.
• To evaluate the mechanical properties and potential applications of the developed hydrogel.

Main Methods:

• A one-pot synthesis method was employed to create an interpenetrating double network hydrogel.
• The hydrogel comprised physically cross-linked gelatin and chemically cross-linked polyacrylamide (PAM) with graphene oxide (GO).
• Shape memory properties were tested through deformation and recovery under controlled temperature and NIR irradiation.

Main Results:

• The synthesized hydrogel exhibited over 76 wt% water content and rapid shape fixing upon cooling.
• Near-infrared (NIR) irradiation induced rapid shape recovery within 60 seconds, attributed to GO's photothermal effect.
• The double-network structure, enhanced by GO, provided high mechanical toughness (strength > 400 kPa, strain > 500%).

Conclusions:

• The developed hydrogel demonstrates efficient shape memory behavior with NIR-triggered recovery, owing to the synergistic effect of gelatin and GO.
• The material's high water content, mechanical robustness, and facile preparation make it a promising candidate for soft actuator applications.
• Optimization of hydrogel composition is key for stable temporary shapes and rapid, controlled recovery.