MXene-cellulose nanofiber composites: toward green, multi-functional, flexible, and highly efficient electromagnetic interference shielding materials

In the current fast-paced digital world, electronic devices have become an inevitable part of our lives, contributing to increasing electromagnetic interference (EMI) that may unfavorably affect our health as well as the precision of miniaturized electronics. Therefore, developing efficient multi-functional EMI shielding materials is of immense interest and importance. EMI shielding technology requires materials possessing high conductivity, permeability, permittivity, processability, and corrosion resistance while being cost-effective and environmentally friendly. The EMI shielding characteristics of MXene, as a novel flourishing 2D material, have been extensively explored in recent years owing to its excellent electrical, thermal, and mechanical properties. Cellulose nanofibers (CNFs) that can be obtained from biomass and upcycling waste, benefiting from numerous advantages such as biodegradability, high aspect ratio, processability, and low cost, can be utilized as a matrix, binder, or derived carbon material. Amalgamating the outstanding properties of these two materials, this paper reviews recent advancements in the field of CNF/MXene nanocomposites. After a brief introduction on CNF and MXene, the role of the structure in the mechanism of attenuation of the electromagnetic wave is discussed. Emphasis is given to the effect of the type and content of the conductive material, thickness, and fabrication method on EMI shielding effectiveness and conductivity. An elaborate discussion on the gaps in achieving multi-functional and flexible composites based on CNF and MXene exhibiting high EMI shielding and potential application in aerospace and wearable sensors is reported as well. Graphical abstract