Ultrastiff Bioinspired Protein-Carbon Nanotube Hybrid Sponge with Shape Memory Effects

Area of Science:

• Materials Science
• Biomaterials Engineering
• Protein Science

Background:

• Natural protein-based biomaterials possess complex hierarchical structures and unique mechanical properties.
• Understanding protein conformational transitions is key to designing advanced biomaterials.

Purpose of the Study:

• To investigate the force-induced conformational transition of silk fibroin in confined porous carbon nanotube sponges.
• To explore the resulting mechanical properties and potential applications of the protein/carbon nanotube hybrid.

Main Methods:

• Experimental investigation of silk fibroin confined within porous carbon nanotube sponges.
• Numerical simulations to analyze the conformational changes.
• Mechanical testing to evaluate stiffness and shape recovery.

Main Results:

• Observed a static-force-induced spatiotemporal
• freezing
• phenomenon in silk fibroin.
• The hybrid material achieved ultrastiffness (>10 MPa) and superelastic shape recovery (>90% recovery strain).
• Silk fibroin's secondary structure transitioned from α-helices/random coils to β-sheets under confinement and low pressure.

Conclusions:

• The secondary conformational transition of silk fibroin is crucial for the observed mechanical properties.
• This study provides a mechanism for creating protein-based smart materials.
• Potential applications include textiles, medicine, and architecture.