Continuous Sandwiched Film Containing Oriented ZnO@HDPE Microfiber for Passive Radiative Cooling

• Published in: Advanced functional materials 2024-07, Vol.34 (28), p.n/a
• Main Authors: Peng, Fei, Ren, Kunlun, Zheng, Guoqiang, Dai, Kun, Gao, Chaojun, Liu, Chuntai, Shen, Changyu
• Format: Article
• Language: English
• Subjects: Abrasion resistance; Coextrusion; coextrusion blow film molding; Cooling; High density polyethylenes; Leaching; low cost; Mechanical properties; Microfibers; passive radiative cooling; Polymer films; Robustness; sandwiched PRC film; Thermal management; Transmittance; Zinc oxide; “structuring” processing
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202400221

Recently, passive radiative cooling (PRC) that realizes thermal management without consuming any energy has attracted increasing attention. However, few studies focus on low‐cost and robust PRC film fabricated by a facile and environmentally friendly method. In this study, via coextrusion blow film molding and water leaching, sandwiched PRC film (SPRCF) is efficiently prepared, and its skin and core layer are respectively high‐density polyethylene (HDPE) film and oriented ZnO@HDPE microfiber layer. Of note, such a sandwiched structure enables SPRCF to possess remarkable mechanical properties, abrasion, and weather resistance. Moreover, with the introduction of ZnO, SPRCF shows lower sunlight transmittance (≈3.8%) but higher mid‐infrared transmittance (≈88.8%), endowing it with remarkable PRC performance (the maximum cooling power of daytime and nighttime are respectively 73.8 and 96.7 W m−2). Furthermore, the decent self‐cleaning performance of SPRCF‐45 endows it with maintenance‐free features outdoors. This work proposes a facile and environmentally friendly method for preparing low‐cost and robust SPRCF, opening a new pathway to develop PRC film following the concept of polymer “structuring” processing. Via coextrusion blow film molding and water leaching, sandwiched PRC film (SPRCF) is efficiently prepared, whose skin and core layer are respectively high‐density polyethylene (HDPE) film and oriented ZnO@HDPE microfiber layer. Moreover, SPRCF shows low sunlight transmittance (≈3.8%) but high mid‐infrared transmittance (≈88.8%), endowing it with remarkable PRC performance.