Waste-to-resource strategy to fabricate wearable Janus membranes derived from corn bracts for application in personal thermal management

Agricultural waste pollution, one of the serious issues faced by human society, has aroused global attention to environmental sustainability. Resource utilization of agricultural waste is of great significance for the development of energy saving and environmentally friendly materials to settle enormous agricultural waste. Herein, the concept of “turning waste into treasure” was proposed in resource utilization of agricultural waste: biomass cellulose derived from corn bracts was used to fabricate wearable Janus membranes for personal thermoregulation application. Wearable Janus membranes composed of zinc oxide nanosheets layer (ZnO-NSs/CBM) and copper nano-coating layer (Cu-NC/CBM) were prepared using corn bracts cellulose membrane (CBM) as the substrate by hydrothermal method and the subsequent magnetron sputtering technique. More importantly, ZnO-NSs/CBM side has high infrared emissivity and visible reflectivity, which is conducive to releasing a mass of human radiation and enhancing the reflection of sunlight. Janus membranes can achieve radiation cooling when ZnO-NSs/CBM faces outwards. Moreover, Cu-NC/CBM side exhibits low infrared emissivity, which helps to return infrared radiation back to the human body. Janus membranes can access radiation insulation effect when Cu-NC/CBM side faces outwards. In addition, wearable Janus membranes with multi-functionality show an outstanding UV resistance, air permeability, flexibility and mechanical property to offer comfort for the wearer. This study not only provides a waste-to-resource strategy to fabricate wearable Janus membranes by using agricultural waste as raw materials but also demonstrates intriguing applications in personal thermal management thanks to its energy conservation and environmental friendliness. Graphical abstract The concept of “turning waste into treasure” was proposed in agricultural resource utilization: cellulose from corn bracts was extracted to fabricate wearable Janus membranes for personal thermoregulation application.