Lightweight MXene/Cellulose Nanofiber Composite Film for Electromagnetic Interference Shielding

Lightweight and high-strength materials with high electromagnetic interference shielding performance are the best solution for electromagnetic pollution. However, the MXene film with extremely high electromagnetic interference shielding effectiveness cannot be extensively applied to the aerospace engineering because of its high density and low mechanical properties. Herein, a MXene/cellulose nanofiber (CNF) composite film with low density and high conductivity (24,875 S m⁻¹) was prepared by using an ice crystal sacrificial template as a pore-forming agent and CNF as a structural reinforcement. The composite film with a small thickness effectively shielded electromagnetic waves since it has a continuous three-dimensional MXene conductive network framework, which serves as a rich interface to facilitate multiple reflections and absorption attenuation of electromagnetic waves. In addition, the absolute electromagnetic interference shielding effectiveness of the prepared film reached 9177 dB cm² g⁻¹. The design concept and approaches adopted in this work are highly efficient and scalable, which provides a bright prospect for the development of the MXene/polymer composites with high electromagnetic interference shielding properties.