Supercritical CO₂-Induced Porous MXene Films for Electromagnetic Interference Shielding and Infrared Stealth

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Lightweight and flexible porous MXene films show potential for electromagnetic interference (EMI) shielding and infrared stealth.
• Current foaming methods struggle to maintain MXene's intrinsic properties and be eco-friendly.

Purpose of the Study:

• To develop a green foaming technique for MXene films using supercritical CO2.
• To investigate the impact of this technique on MXene's structure and properties for EMI shielding and infrared stealth.

Main Methods:

• Employed supercritical CO2 foaming technology on dense MXene films.
• Utilized the phase transition of supercritical CO2 to induce bubble nucleation and growth, creating a porous architecture.
• Extended the strategy to other 2D films like graphene oxide.

Main Results:

• Achieved green foaming of MXene films without compromising nanosheet structure.
• The foamed porous MXene film demonstrated an EMI shielding effectiveness of ~73.2 dB, a 21% increase over pristine films.
• Attained an absolute shielding effectiveness of 23160 dB·cm²/g, outperforming most reported MXene-based porous materials.
• Showcased excellent infrared thermal camouflage performance.

Conclusions:

• Supercritical CO2 foaming is an effective and adaptable method for creating porous 2D materials.
• Porous MXene films offer significant advancements in EMI shielding and infrared stealth for safety protection applications.