Multifunctional wood-derived cellulose/Ti3C2Tx composite films enhanced by densification strategy for electromagnetic shielding, Joule/solar heating, and thermal camouflage

In the era of increasing reliance on electronic devices, the development of flexible smart composite films that offer multifunctional capabilities such as electromagnetic shielding, sensing, infrared stealth, and autonomous heating is becoming increasingly significant. In this study, we fabricated polydopamine-modified cellulose scaffold/MXene composite films (PCM) using a densification strategy, resulting in films with a thickness of only 33 μm, outstanding tensile strength of 235.28 MPa, and excellent electromagnetic shielding effectiveness of 44.6 dB. The PCM also demonstrates remarkable electrothermal performance, reaching temperatures of up to 610 °C at 5 V, and exhibits excellent photo-thermal conversion performance, along with good cycling stability and tunability. Additionally, the PCM's low infrared emissivity provides it with exceptional infrared stealth capabilities, effectively concealing a high surface temperature ranging from 250 °C to 25 °C. The PCM's ability to detect human body movement and light-driven actuation for bionic motions underscores its flexibility and utility as a sensor. Therefore, this efficient and versatile approach provides a promising method for synthesizing multifunctional MXene-based composite films, achieving satisfactory mechanical properties, high electromagnetic interference shielding, and effective thermal management for wearable smart devices and military applications.