【Frontiers in HaiChuan Chemical Technology】A team from China University of Mining and Technology has developed a high-performance passive cooling biomimetic Janus polylactic acid superfabric

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A team from China University of Mining and Technology has developed a high-performance passive cooling biomimetic Janus poly(lactic acid) metafabric. Recently, the team led by Professor He Xinjian and Associate Professor Xu Huan from the Institute of Occupational Health at China University of Mining and Technology published their latest research findings in the journal ACS Applied Materials & Interfaces, titled “Stereocomplexation-Enhanced Biomimetic Janus Poly(Lactic Acid) Metafabric for High-Power Passive Personal Cooling”. China University of Mining and Technology is the lead institution; the first author of the paper is Li Jiaqi, a doctoral student from the School of Safety Engineering, while the corresponding authors are Professor He Xinjian and Associate Professor Xu Huan. Focusing on the heat management needs of individuals in high-temperature environments, this study developed a biomimetic Janus polylactic acid superfabric that combines radiative cooling with directed sweat transport, achieving new progress in the field of sustainable personal cooling textiles. The Janus polylactic acid superfabric is based on the concept of \"plant-like transpiration\"; it combines a hydrophilic SCPLA/SiO₂ nanofiber layer with a hydrophobic PLA micofiber substrate to create oriented sweat-guiding channels from the inside outward. This design not only reduces the retention of sweat on the skin side but also enables additional heat dissipation through evaporation from the outer layer, allowing the material to possess radiative cooling, evaporative cooling, and comfort in wear – offering a new material design approach for high-temperature work and personal protection in outdoor environments. In terms of material structure, the research team improved the structural stability and mid-infrared emissivity of the polylactic acid matrix through the stereocompounding of PLLA and PDLA molecular chains, and introduced size-optimized SiO₂ nanoscale scatterers to enhance the ability to scatter sunlight. The synergistic effect between molecular structure regulation and micro-nano fiber morphology design enables this material to maintain excellent flexibility and mechanical stability, as well as good breathability and moisture permeability, thereby laying the foundation for its cooling properties. Unlike ordinary hydrophobic fiber membranes that tend to cause sweat retention, this Janus superfabric relies on the combined effect of a pore size gradient and a wettability gradient to achieve rapid and directed sweat transport. Experiments show that its sweat transport time is less than 21 s, enabling it to quickly transport liquids from the skin surface to the outer layer where they can diffuse and evaporate. This superfabric exhibits excellent spectral selectivity: the solar reflectance reaches 94.2%, while the mid-infrared emissivity reaches 93.3%. This means that the material can minimize solar heat input while efficiently radiating heat outward through the atmospheric window. Furthermore, the stereocompounding enhances the vibration absorption of molecular chains in the mid-infrared region, while the nanoscale SiO₂ scatterers and fiber structure improve the scattering and reflection capability of sunlight; together, these factors enable efficient radiative cooling. Under direct sunlight in outdoor conditions, this Janus polylactic acid superfabric exhibits significant practical cooling capabilities: it can reduce the temperature by up to 12.1 °C compared to bare skin, and by up to 7.2 °C compared to cotton fabric. Under simulated sweating conditions, the directed transport of sweat and evaporative cooling can further achieve an additional cooling effect of 7.6 °C. In other words, this material not only shows excellent performance in laboratory spectral data, but also demonstrates potential for use in personal heat management applications in real-world conditions. Based on biodegradable polylactic acid, this research integrates biomimicry, molecular stereoregulation, and Janus structure design to achieve effective synergy between radiative cooling and evaporative cooling, providing a solution that combines performance and sustainability for the development of thermal management textiles in high-temperature environments. This achievement not only expands the application scope of polylactic acid fiber materials in the field of functional protection, but also provides new research approaches for the development of intelligent protective textiles and personal protection materials for use in extreme environments.