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

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 (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.