Wearable Janus‐Type Film with Integrated All‐Season Active/Passive Thermal Management, Thermal Camouflage, and Ultra‐High Electromagnetic Shielding Efficiency Tunable by Origami Process

Abstract

AbstractMultifunctional films with integrated temperature adjustment, electromagnetic interference (EMI) shielding, and thermal camouflage are remarkably desirable for wearable products. Herein, a novel Janus‐type multifunctional ultra‐flexible film is fabricated via continuous electrospinning followed by spraying. Interestingly, in the polyvinyl alcohol (PVA)/phase change capsules (PCC) layer (P1), the PCC is strung on PVA fibers to form a stable “candied haws stick” structure that obviates slipping or falling off. The film with sufficient melting enthalpy (141.4 J g−1) guarantees its thermoregulation capability. Simultaneously, its high mid‐IR emissivity (90.15%) endows the film with radiative cooling properties (reducing temperature by 10.13 °C). Mechanical strength is significantly improved by superimposing a polylactic acid (PLA) layer (P2) on its surface. By spraying a thin MXene layer on the PLA surface of P2P1 film, the obtained (MXene/P2P1) MP2P1 film is endowed with satisfactory low‐voltage heating, photo‐thermal and superior thermal camouflage performance, achieving all‐season thermal comfort. Impressively, the flexible MP2P1 film achieves enhanced EMI shielding effect from 50.3 to 87.8 dB through a simple origami process, which simplifies the manufacturing process of high‐performance EMI shielding materials. In brief, the multifunctional Janus‐type MP2P1 film is an attractive candidate for future wearable products with personalized thermal management and anti‐electromagnetic radiation.