Electromagnetic properties of graphene aerogels made by freeze-casting

We report a comprehensive analysis of the Electromagnetic (EM) properties of graphene aerogel-based shielding materials prepared by freeze casting. Controlling the freeze casting temperature allows for tailoring the pore sizes of graphene aerogels, which further affects the permittivity and EM shielding properties. To protect the aerogel structures from collapsing during high temperature heat-treatment, we used Melamine sponge (MS) as a supporting strut. Through a comparison with bare aerogels, we find that the presence of MS can significantly modify both the reflection and absorption performances and that an absorption-dominated shielding material can be obtained. After heat-treatment at 1000 degrees C for two hours, the MS-supported aerogel sample (MS-aero) showed a shielding efficiency of 55.8 dB. Our work shows that the material composition and the microstructural architecture of aerogels crucially influence their electromagnetic shielding efficiency.

Automated summary

This study presents a comprehensive analysis of the electromagnetic properties of graphene aerogel-based shielding materials prepared through freeze casting. The control of freeze casting temperature allows for customization of pore sizes, affecting permittivity and shielding properties. The use of Melamine sponge as a supporting strut during high temperature heat-treatment significantly modifies the performance of the material, resulting in an absorption-dominated shielding material.