Superior Impact-Resistant Composite Hydrogels Through an Ionic Coupling Strategy

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Hydrogels are promising for impact resistance but struggle with simultaneous network and interface reinforcement.
• High strain-rate loading challenges existing hydrogel performance.

Purpose of the Study:

• To develop a composite hydrogel with enhanced impact resistance.
• To overcome limitations in reinforcing both hydrogel networks and interfaces.

Main Methods:

• Fabrication of a composite hydrogel using poly(vinyl alcohol) (PVA) matrix and chitosan-sodium alginate nanofibers (CSNFs).
• Utilized sodium citrate as a multifunctional ionic coupler to strengthen PVA, reinforce CSNF, and improve fiber-matrix interfaces.
• Employed molecular-level experimental and simulation analyses.

Main Results:

• Achieved superior impact resistance (426.7 MPa) and toughness (106.4 MJ m⁻³) at 7000 s⁻¹, outperforming solid polymers.
• Maintained excellent tensile properties (54.2 MPa strength, 590% strain).
• Demonstrated efficient stress transfer and energy dissipation via integrated composite network and layered microstructure.

Conclusions:

• Ionic coupling is an effective strategy for creating hydrogels with extreme impact resistance.
• The developed composite hydrogel shows potential for impact protection, damping, and energy absorption applications.
• Broadens the application scope of soft materials in demanding environments.