Structurally engineered lignin-based robust, conductive ionic hydrogels via DMSO-assisted dual-network strategy for...

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Ionic hydrogels are crucial for electronic skins and wearable sensors, but face challenges like poor mechanical strength and unstable conductivity.
• Existing materials often exhibit a trade-off between mechanical robustness and ionic transport efficiency.
• Developing advanced hydrogels with integrated functionalities is essential for practical applications in health monitoring and human-machine interaction.

Purpose of the Study:

• To engineer robust, multifunctional ionic hydrogels using a lignin-based dual-network strategy.
• To overcome the limitations of conventional ionic hydrogels, including mechanical weakness and swelling.
• To create a versatile material for advanced applications like wearable sensors and electronic skins.

Main Methods:

• A DMSO-assisted dual-network strategy was employed, modifying alkaline lignin into a multifunctional building block (LigBM3-C16).
• Esterification and quaternization imparted crosslinkable sites and antibacterial properties to the lignin derivative.
• Copolymerization with acrylic acid and acrylamide, followed by FeCl3 solvent exchange, formed a hydrate coordination network.

Main Results:

• The resulting LigBM3-C16-Fe hydrogels demonstrated excellent tensile strength (3.38 MPa) and toughness (9.76 MJ/m-3).
• High ionic conductivity (27.4 mS cm-1) was achieved, balancing mechanical robustness with ion transport.
• The hydrogels exhibited broad-spectrum antibacterial and antioxidant activity due to Fe3+ coordination and quaternized lignin.

Conclusions:

• The developed lignin-based ionic hydrogels offer a robust and multifunctional platform for flexible conducting materials.
• These hydrogels function effectively as stable strain sensors for real-time human motion monitoring and gesture control.
• The study presents a facile method for creating advanced ionic hydrogels, overcoming key limitations for wearable electronics.