High-strength, super-tough, and durable nacre-inspired MXene/heterocyclic aramid nanocomposite films for electromagnetic interference shielding and thermal management

2D transition-metal carbides, known as MXenes, are among the most promising electromagnetic interference (EMI) shielding materials due to their outstanding metal-like electrical conductivity and high hydrophilicity. However, a significant drawback of these materials is mechanical brittleness and inferior oxidation stability, which impedes their applications in lightweight, flexible electronics. Herein, inspired by natural nacre, the large-area, high-strength, super-tough, and durable lamellar MXene/heterocyclic aramid (HA) nanocomposite films are fabricated through a blade-coating process plus sol-gel-film conversion technique. The MXene/HA nanocomposite film containing 20 wt% MXene possesses extraordinary mechanical performance, that is, high tensile strength (322.6 MPa), enormous strain (16.2%), exceptional toughness (43.3 MJ m−3), remarkable folding endurance, and good structural stability, which are attributed to nacre-like lamellar structure and hydrogen-bonding interaction between MXene and HA. More interestingly, due to the formation of the continuous MXene conductive paths, the MXene/HA nanocomposite film filled with 80 wt% MXene presents an EMI SE of 43.0 dB at a thickness of 13.0 μm, a high EMI shielding effectiveness of 14529.1 dB cm2 g−1 and a superior in-plane thermal conductivity of 11.5 W m−1 K−1. The nacre-like film also exhibits excellent oxidation stability, thermal stability, flame retardancy, and photothermal performance. Thus, such high-performance MXene-based films fabricated by a facile and scalable manufacturing method show great potential in the field of electromagnetic shielding and thermal management.