Robust carbon nanotube foam for efficient electromagnetic interference shielding and microwave absorption.

Area of Science:

• Materials Science
• Nanotechnology
• Composite Materials

Background:

• Electromagnetic interference (EMI) poses a significant challenge in modern electronic devices and systems.
• Developing lightweight, high-performance EMI shielding materials is crucial for applications in aerospace, automotive, and electronics.

Purpose of the Study:

• To develop a novel, lightweight, and robust carbon nanotube (CNT)/chitosan (CS) foam for effective EMI shielding.
• To investigate the EMI shielding performance, mechanical properties, and absorption characteristics of the fabricated CNT/CS foam.

Main Methods:

• Unidirectional freeze-drying method was employed for the facile assembly of CNT/CS foams.
• Characterization of foam density, electromagnetic interference shielding effectiveness (SE), specific SE, and absorption coefficient.
• Evaluation of mechanical properties, including compressive strength and modulus.

Main Results:

• The CNT/CS foam achieved an excellent EMI shielding effectiveness of 37.6 dB at a low density of 17.6 mg·cm⁻³.
• The specific SE reached up to 8556 dB·cm²·g⁻¹, attributed to well-formed conductive networks.
• The absorption coefficient was as high as 81.73% under high EMI SE.
• Chitosan addition significantly enhanced compressive strength (84% increase) and modulus (149% increase) compared to pure CNT foam.

Conclusions:

• The developed CNT/CS foam is a high-efficiency, lightweight EMI shielding material with remarkable performance.
• The material exhibits superior mechanical robustness due to chitosan integration.
• Potential applications are identified in aerospace, automotive, and electronic devices requiring effective EMI shielding.