Controlled microphase separation and strain programming in hydrogel fibers toward biomimetic architectures and...

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Natural spider silk offers exceptional toughness, strength, and functionality, making it a model for advanced materials.
• Synthetic replication of spider silk's complex structure and properties, especially through scalable manufacturing, presents significant challenges.

Purpose of the Study:

• To develop a scalable wet-spinning method for fabricating spider silk-like hydrogel fibers.
• To mimic the hierarchical structure and mechanical properties of natural spider silk using a composite polymer system.

Main Methods:

• Utilized wet-spinning of sodium polyacrylate and polyacrylamide (PANa-PAM) composite polymer hydrogels.
• Employed antisolvent-induced phase separation to control microphase morphology.
• Applied post-drawing for strain programming to achieve polymer alignment and crystallization.

Main Results:

• Fabricated PANa-PAM fibers with aligned microfibrils, nanoclusters, and β-sheet-like crystallites, mirroring spider silk's architecture.
• Achieved high toughness (118.7 MJ m⁻³), tensile strength (172.3 MPa), 50% elastic strain recovery, and 96% damping efficiency.
• Demonstrated functionalities including 60% supercontraction and moisture sensitivity, comparable to natural spider silk.

Conclusions:

• The developed bioinspired wet-spinning technique successfully replicates spider silk's hierarchical structure and properties in synthetic hydrogel fibers.
• This approach provides a viable pathway for producing high-performance, intelligent fibers for applications in wearable technology.
• The study highlights the potential of composite polymer hydrogels for creating advanced biomimetic materials.