Nacre-inspired strong nanopapers of aramid nanofiber-integrated montmorillonite nanoplates, cellulose nanofibrils, and Ag nanowires for high-performance electrical heaters

Abstract

High-performance materials with versatile functionalities are highly desirable for modern electronic devices. Inspired by natural nacre with a layered aragonite platelet/chitin nanofiber/protein ternary structure, a high-strength nanopaper is fabricated by introducing two-dimensional (2D) montmorillonite (MTM) nanoplates and 1D cellulose nanofibrils (CNFs) into a 3D aramid nanofiber (ANF) framework via vacuum filtration. The obtained ANF/MTM/CNF nanopapers yield record-high tensile strength (δ_c) (484.58 MPa) and outstanding toughness (ε_c) (53.70 MJ m⁻³). Furthermore, the incorporation of Ag nanowires (AgNWs) enables the nanopapers to achieve high heating temperatures (up to ∼200 °C) and satisfactory electromagnetic interference shielding effectiveness (24.14 dB). Moreover, the ANF/MTM/CNF/AgNW nanopapers maintain excellent mechanical properties, where their δ_c and ε_c are 488.48 MPa and 52.74 MJ m⁻³. Normalized by weight, the specific tensile strength of the nanopapers reaches 359 MPa g⁻¹ cm³, that is even superior to that of a commercial titanium alloy (257 MPa g⁻¹ cm³). Besides, the nanopapers have outstanding mechanical durability, in which, being electrically heated at 170 °C for 1 h, the nanopapers still retain 93.69% of the original δ_c. This bioinspired nanopaper presents a novel approach to create mechanically strong nanopapers with diverse outstanding functionalities, catering to the demands of high-end electronics.