Acid-Hydrolysis Nanoengineering of MXene-Based Dual Cross-Linked Hydrogels for Multifunctional Applications

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Conductive hydrogels often suffer mechanical degradation due to nanofiller dispersion.
• Polydopamine (PDA) is used for nanofiller dispersion but can compromise mechanical properties.
• Achieving synergistic enhancement in hydrogel properties remains a challenge.

Purpose of the Study:

• To develop a novel nanoengineering strategy to overcome the mechanical deterioration in polydopamine-assisted conductive hydrogels.
• To create a hydrogel with enhanced conductivity, mechanical strength, and advanced functionalities.
• To demonstrate the potential of the developed hydrogel in wearable sensors and energy harvesting devices.

Main Methods:

• Sequential introduction of polydopamine (PDA) and waterborne polyurethane (WPU) to inhibit MXene restacking.
• Acid-catalyzed hydrolysis of polyacrylamide to induce in situ network reconstruction and densification.
• Characterization of hydrogel properties including mechanical strength, conductivity, and sensing capabilities.

Main Results:

• The H-PUDMP hydrogel achieved high fracture strain (1782%) and fracture stress (0.43 MPa) with good conductivity (6.09 mS·cm^-1).
• Demonstrated segmented temperature-resistance response for broad-range, self-compensating temperature sensing.
• Successfully functioned as a wearable sensor for human motion monitoring and in a triboelectric nanogenerator (TENG) with high output (210 V).

Conclusions:

• The acid-catalyzed hydrolysis strategy effectively resolves the trade-off between mechanical properties and conductivity in hydrogels.
• The developed hydrogel exhibits superior integrated properties suitable for advanced electronic applications.
• This approach provides a new paradigm for nanoengineering functional hydrogel electronics.