3D-Printed Crosslinked Nanocellulose-MXene Hydrogels and Aerogels with High Strength and Conductivity

Area of Science:

• Materials Science
• Nanotechnology
• Additive Manufacturing

Background:

• Extrusion-based 3D-printing offers potential for integrating nanomaterials like MXenes.
• Fabricating stable 3D-printed MXene structures is challenging due to poor mechanical stability and rheology.
• Developing suitable MXene-based inks is crucial for advanced applications.

Purpose of the Study:

• To develop a stable MXene ink formulation for 3D-printing.
• To create mechanically robust and conductive 3D-printed structures.
• To demonstrate the potential of these structures in iontronic devices.

Main Methods:

• Formulation of a MXene ink incorporating cellulose nanofibers (CNFs) as rheology modifiers.
• Utilizing a one-step freeze-induced crosslinking process for structure fabrication.
• Characterization of mechanical strength, electrical conductivity, and electrochemical performance.

Main Results:

• The developed ink formulation enhanced structural integrity and enabled freeze-induced crosslinking.
• 3D-printed structures exhibited high mechanical strength (supporting 10,000x weight) and conductivity (>195 S m⁻¹).
• Specific capacitance reached 240 F g⁻¹ at 5 mV s⁻¹, with demonstrated supercapacitor applications.

Conclusions:

• The CNF-modified MXene ink facilitates the fabrication of stable, lightweight, and conductive 3D-printed structures.
• These structures show significant promise for advanced iontronic devices, including supercapacitors.
• The study overcomes key challenges in 3D printing with MXenes for functional material applications.