Bioinspired, mechanically durable MXene-pineapple leaf nanocellulose composite films with laminated structure for...

Research on the application of MXene/nanocellulose composite films in electromagnetic interference (EMI) shielding and thermal management devices has attracted considerable attention. However, it remains a challenge to create composite films that maintain a good balance between mechanical and application properties as well as ensure their remarkable structural stability and reliability under harsh conditions. Herein, an MXene-pineapple leaf nanocellulose-based composite film (MXene/PANLF (MP)/PALNF/Si) with a laminated structure and a biomimetic lotus leaf surface, combining mechanical robustness and versatility, is prepared via a two-step vacuum filtration, hot-pressing, and silicone coating method. Benefiting from the elaborate design of a nanocellulose supporting layer and an EMI shielding functional layer, an MP-III/PALNF composite film exhibits remarkable mechanical properties (tensile strength of 256.23 MPa and toughness of 33.68 MJ/m³), EMI shielding efficiency (SE) of up to 34 dB, and specific SE (SSE/t) as high as 5237.3 dB cm² g^-1. The silicone coating provides the hydrophilic MP-III/PALNF composite film with superhydrophobicity and outstanding self-cleaning capability, resulting in satisfactory durability against solutions, moisture, and structural deformation. In addition, an MP-III/PALNF/Si composite film exhibits high electrical conductivity, desirable low voltage-driven Joule heating properties, and good heat-dissipation capabilities. Therefore, we can say that our multifunctional MP-III/PALNF/Si composite film holds considerable potential for electromagnetic shielding and thermal management applications in smart and portable wearable electronics.