Vacuum-assisted multi-layer bacterial cellulose/polydopamine-modified Mxene film for joule heating, photo thermal, and humidity sensing

Multifunctional films have potential applications in smart wearable devices and portable electronic products. Yet, it is always a challenge to ensure these materials simultaneously to have flexible, strong, and functional properties during the material preparation process. Herein, bacterial cellulose/polydopamine modified by MXene (BC/PM) multi-layer films is prepared by vacuum-assisted self-assembly. The micromorphology, phase composition, and application performance of this composite film were systematically characterized. The mechanical properties test indicates that the BC/PM multi-layer film exhibits an excellent reinforcement effect. The tensile strength and elongation of the three-layer BC/PM film reach 181.6 MPa and 8.9%, respectively. For multifunctional applications, the BC/PM multi-layer film shows remarkable electric heating and excellent photothermal properties, for example, it can be heated up to 85 °C at a constant voltage of 6 V for 20 s, and its temperature can increase from room temperature to 90 ℃ after 250 W infrared lamp is irradiated for 30 s. Furthermore, the sample has potential high sensitivity and high response speed to humidity changes. This research will provide a data basis and theoretical reference for the practical application of bacterial cellulose-based multifunctional films.