Hydrophobic Interaction-Directed Solvent-Free Ambient-Pressure-Dried MXene Aerogels.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Scalable production of multifunctional MXene aerogels using solvent-free ambient-pressure drying (APD) is challenging.
• Existing methods often struggle with maintaining structural integrity and achieving desired properties.

Purpose of the Study:

• To develop a general, scalable, and solvent-free route for assembling MXene aerogels with programmable hydrophobicity, mechanics, and functionalities.
• To engineer MXene aerogels with enhanced mechanical strength, switchable electromagnetic properties, and superior thermal protection.

Main Methods:

• A hydrophobic interaction-directed assembly strategy using MXene, chitosan (CS), and glutaraldehyde (GA).
• Selective reduction of CS amine groups to suppress capillary forces during solvent-free APD.
• Composition tuning to achieve different electromagnetic functionalities.

Main Results:

• Achieved a 4,477% compressive strength enhancement compared to conventional MXene aerogels.
• Demonstrated switchable electromagnetic functionality: 76 dB microwave shielding with 25.6 wt.% CS and 6.4 GHz broadband microwave absorption with 67.4 wt.% CS.
• Exhibited exceptional thermal protection with a 60% limiting oxygen index, outstanding thermal insulation, and early fire-warning capability.

Conclusions:

• The developed solvent-free APD method offers a scalable route for producing robust MXene aerogels with integrated mechanics and functionalities.
• These aerogels show significant potential for applications in aerospace and energy systems due to their enhanced properties.
• The strategy provides a general approach for assembling other non-structured aerogels with tailored performance.