Wearable Janus MnO2 hybrid membranes for thermal comfort management applications

Abstract

With the continuous development and utilization of sustainable resources, infrared energy-saving material is one of the functional materials and plays an extremely significant role in thermal management applications. Herein, the wearable Janus MnO2 hybrid membranes, composed of asymmetric radiation properties on each side, were fabricated by layer-by-layer assembly process and subsequent magnetron sputtering. In this hybrid system, the ultra-long MnO2 nanowires (ULMNWs) were prepared by hydrothermal process and used as substrates, the MnO2 nanosheets coated ULMNWs (ULMNWs@MNSs) were fabricated via hydrothermal growth of MnO2 nanosheets on nanowire surfaces, then the ULMNWs suspension and the ULMNWs@MNSs suspension were formed into a bilayer membrane by a sequential suction filtration. Finally, silver nanoparticles were sputtered uniformly on the surface of ULMNWs side by magnetron sputtering to form a silver nano-coating coated ULMNWs (ULMNWs@ANC). More importantly, the average infrared reflectivity of ULMNWs@ANC side over wavelength range of 3–18 μm can reach 81.6% and the ULMNWs@MNSs side with rough surface exhibits lower infrared reflectivity of about 39.5%. Additionally, the wearable Janus MnO2 hybrid membranes also exhibit excellent flexibility, and it could be benefit to enhance the comfort of the user. Therefore, Janus membranes are promising for the future applications in wearable electronics and other fields.