Multifunctional PPy/MXene decorated polylactic acid film for thermal management and electromagnetic interference shielding

Composite films composed of biodegradable materials possessing flexibility, thermal regulation capabilities, and electromagnetic interference shielding attributes represent optimal selections for wearable items and the packaging of devices. Here, we employ a simple alternating immersion and spray-coating process to fabricate flexible multifunctional films by combining hydrophobic PLA electrospun film with PPy and MXene, and investigate the thermal management and electromagnetic interference shielding properties of the films. Through alternating immersion, PPy can be rapidly in-situ polymerized on the PLA film, enhancing the surface roughness of the fibers, enabling firm integration of MXene with the film. Benefiting from the broad wavelength absorption characteristics of PPy, the solar absorption capacity of the film is significantly enhanced (97.16 %), endowing it with excellent photothermal conversion capability. Meanwhile, the high conductivity of MXene imparts the composite film with controllable and stable active heating ability, meeting heating demands under complex weather conditions. Finally, inspired by origami techniques the electromagnetic interference shielding performance of films with different folding frequencies was compared. It was found that attributed to the increased reflection paths, the film exhibited a significant improvement in electromagnetic interference shielding performance (32.58 dB to 51.96 dB) after folding. In brief, this biodegradable multifunctional composite film is an attractive candidate for future wearable products or devices packaging.