Wearable Janus‐Type Film with Integrated All‐Season Active/Passive Thermal Management, Thermal Camouflage, and Ultra‐High Electromagnetic Shielding Efficiency Tunable by Origami Process
Xiaolong Li, Xinxin Sheng, Yu Fang, Xinpeng Hu, Shang Gong, Mengjie Sheng, Xiang Lu, Jinping Qu
Abstract
Abstract Multifunctional 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 (P 1 ), 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 (P 2 ) on its surface. By spraying a thin MXene layer on the PLA surface of P 2 P 1 film, the obtained (MXene/P 2 P 1 ) MP 2 P 1 film is endowed with satisfactory low‐voltage heating, photo‐thermal and superior thermal camouflage performance, achieving all‐season thermal comfort. Impressively, the flexible MP 2 P 1 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 MP 2 P 1 film is an attractive candidate for future wearable products with personalized thermal management and anti‐electromagnetic radiation.