Functional Carbon Springs Enabled Dynamic Tunable Microwave Absorption and Thermal Insulation.

Area of Science:

• Materials Science
• Nanotechnology
• Electromagnetics

Background:

• Electromagnetic (EM) wave pollution and thermal damage threaten sensitive instruments.
• Functional aerogels can mitigate EM interference and provide thermal insulation.
• Existing materials face challenges balancing microwave absorption (MA) and thermal protection.

Purpose of the Study:

• To develop a novel carbon-based aerogel for simultaneous EM wave and thermal protection.
• To investigate the relationship between microstructure, MA performance, and thermal insulation.
• To demonstrate a tunable and switchable MA capability.

Main Methods:

• Design and synthesis of functional carbon spring (FCS) aerogels.
• Characterization of microstructure, MA performance, and thermal conductivity.
• Compression strain manipulation to tune properties.
• Numerical simulations for performance comparison.

Main Results:

• FCS aerogels exhibit a unique lamellar multi-arch microstructure.
• Tunable effective absorption bandwidth (EAB) up to 13.4 GHz (84% of spectrum) with compression strain.
• Novel "on-off" switchability of MA performance observed.
• Ultralow thermal conductivity (12.7 mW m⁻¹ K⁻¹) and anisotropic heat transfer.
• FCS outperforms honeycomb and isotropic aerogels in thermal management.

Conclusions:

• FCS aerogels effectively address the conflict between MA and thermal insulation.
• The material demonstrates significant potential for dual electromagnetic-thermal protection applications.
• Establishment of an "electromagnetic-thermal" dual-protection material database highlights superiority.