Electromagnetic Interference Shielding in Lightweight Carbon Xerogels

Abstract

Electromagnetic interference (EMI) is considered a dangerous threat that simultaneously affects the sensitivity of electronic devices and the human body owing to the rapidly growing usage of high-frequency electronic and wireless devices. In this study, we demonstrated the EMI shielding properties of lightweight and electrically conducting three-dimensional (3D) resorcinol-formaldehyde carbon xerogels of 2.4 mm thickness in the frequency range of 10-15 GHz (X-Ku band). Brittle carbon xerogels revealed complex porous structures, in which pores of irregular geometrical shapes were randomly distributed in all directions. Electrochemical characterization revealed that the material behaved as an electrical double-layer capacitor. The carbon xerogels displayed reflection-dominated (~ 84%) shielding behavior, with a total EMI shielding effectiveness (SE) value of ~ 61 dB. The absorption process also contributed (~ 16%) to the total SE. owing to the presence of a complex porous network, which led to the suppression of the EM waves within the carbon xerogel.

Carbon xerogel, porous material, electrochemical characterization, EMI shielding