Super Tough Multifunctional MXene/PAA-CS Double Network Hydrogels with High Mechanical Sensing Properties and...

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Hydrogels are promising for flexible electromagnetic interference (EMI) shielding due to their mechanical properties and water content.
• Existing EMI shielding hydrogels often lack mechanical robustness, limiting their practical applications.
• Developing mechanically strong and highly effective EMI shielding hydrogels is crucial for advanced electronics.

Purpose of the Study:

• To engineer robust and highly stretchable MXene/polyacrylic acid-chitosan hydrogels for effective EMI shielding.
• To enhance hydrogel mechanical properties and fracture energy using a double network strategy and the Hofmeister effect.
• To investigate the terahertz (THz) EMI shielding performance and its tunability.

Main Methods:

• Fabrication of MXene/polyacrylic acid-chitosan hydrogels using a double network strategy.
• Strengthening and toughening the hydrogels with ammonium sulfate ((NH4)2SO4) solution.
• Characterization of mechanical properties, strain sensitivity, fracture energy, and THz EMI shielding effectiveness.

Main Results:

• The developed hydrogels exhibit outstanding stretchability, strain sensitivity (11.66), and fracture energy (≥9 kJ m⁻²).
• Achieved high EMI shielding effectiveness of 73.8 dB in the THz range.
• Demonstrated robust shielding performance after mechanical stress and dehydration, with tunable properties based on composition and thickness.

Conclusions:

• MXene/PAA-CS double-network hydrogels offer a promising solution for advanced flexible EMI shielding applications.
• These materials are suitable for use in demanding environments within flexible electronics and soft robotics.
• The study highlights the potential of combining double network strategies and the Hofmeister effect for high-performance functional hydrogels.