Electromagnetic interference shielding in lightweight carbon xerogels

With the increasing use of high-frequency electronic and wireless devices, electromagnetic interference (EMI) has become a growing concern due to its potential impact on both electronic devices and human health. In this study, we demonstrated the performance of lightweight, electrically conducting 3D resorcinol-formaldehyde carbon xerogels, of 2.4 mm thickness, as an EMI shieldin the frequency range of 10-15 GHz (X-Ku band). The brittle carbon xerogels revealed complex porous structures with irregularly shaped pores that were randomly distributed. Electrochemical characterization revealed that the material behaved as an electrical double-layer capacitor. The carbon xerogels displayed reflection-dominated (similar to 84%) shielding behavior, with a total EMI shielding effectiveness (SE) value of similar to 61 dB. The absorption process also contributed (similar to 16%) to the total SE. This behavior is attributed to the carbon xerogels' complex porous network, which effectively suppresses EM waves.