Passive radiative cooling has garnered significant attention in energy-saving applications as it is an effective way to cool to temperatures below ambient without external energy input. Successful cooling performances can be achieved by carefully selecting metal oxides with narrow absorption bands that lie entirely within the atmospheric window of 8−13 μm, thereby allowing radiative transfer between terrestrial objects and outer space. Highly scalable, metal oxide-doped fibers made from recyclable polystyrene herein are proposed and demonstrated. The material exhibits nearly 100% reflectivity in the visible and near-infrared (IR) range, and under direct solar irradiation, the material can cool by up to 22.3 °C below the ambient temperature without energy input due to strong emissivity in the atmospheric window. This cooling persists despite nonideal atmospheric conditions and convective/conductive heat exchange. Microsized fiber-based radiative cooling is reported for the first time. Unlike film-based passive radiative cooling materials, fibers are relatively simple to manufacture, flexible, lightweight, and low in cost. Therefore, such a material may be suitable for large-scale applications such as buildings to supplement air conditioning or as a wearable fabric to promote subambient cooling for the wearer.

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用于被动辐射冷却的高效聚苯乙烯/金属氧化物纤维复合材料

被动辐射冷却在节能应用中引起了广泛关注，因为它是一种无需外部能量输入即可将温度冷却至低于环境温度的有效方法。通过仔细选择完全位于 8-13 μm 大气窗口内的窄吸收带的金属氧化物，可以实现成功的冷却性能，从而允许陆地物体和外层空间之间的辐射传输。本文提出并演示了由可回收聚苯乙烯制成的高度可扩展的金属氧化物掺杂纤维。该材料在可见光和近红外 (IR) 范围内表现出近 100% 的反射率，并且在直接太阳照射下，由于大气窗口中的强发射率，该材料可以在没有能量输入的情况下冷却至低于环境温度 22.3°C . 尽管不理想的大气条件和对流/传导热交换，这种冷却仍然存在。首次报道了基于微尺寸纤维的辐射冷却。与基于薄膜的被动辐射冷却材料不同，纤维制造相对简单、柔韧、重量轻且成本低。因此，这种材料可能适用于大规模应用，例如建筑物以补充空调或作为可穿戴织物以促进穿着者的低温冷却。