Cellulose composite aerogel for highly efficient electromagnetic interference shielding

Abstract

An ultra-light and highly conductive cellulose composite aerogel was fabricated by a simple, efficient and environmentally benign strategy. The scaffold structure was well designed from nanofibrillar networks to nanosheet networks by controlling the concentration of cellulose in the sodium hydroxide/urea solution. The obtained conductive aerogel was first reported as an electromagnetic interference shielding material; it exhibits an electromagnetic interference (EMI) shielding effectiveness of ∼20.8 dB and a corresponding specific EMI shielding effectiveness as high as ∼219 dB cm³ g⁻¹ with microwave absorption as the dominant EMI shielding mechanism in the microwave frequency range of 8.2–12.4 GHz at a density of as low as 0.095 g cm⁻³. This result demonstrates that this type of green conductive aerogel has the potential to be used as lightweight shielding material against electromagnetic radiation, especially for aircraft and spacecraft applications.