Superhydrophobic bilayer coating for passive daytime radiative cooling
Passive radiative cooling is an energy-free cooling method by exchanging thermal radiation with the cold universe through the transparent atmospheric window. Spectrum tailoring of the radiative cooler is the key to daytime radiative cooling in previously reported works. In addition, radiative cooler...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
De Gruyter
2023-10-01
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| Series: | Nanophotonics |
| Subjects: | |
| Online Access: | https://doi.org/10.1515/nanoph-2023-0511 |
| _version_ | 1826963960148000768 |
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| author | Zhao Bin Xu Chengfeng Jin Cheng Lu Kegui Chen Ken Li Xiansheng Li Lanxin Pei Gang |
| author_facet | Zhao Bin Xu Chengfeng Jin Cheng Lu Kegui Chen Ken Li Xiansheng Li Lanxin Pei Gang |
| author_sort | Zhao Bin |
| collection | DOAJ |
| description | Passive radiative cooling is an energy-free cooling method by exchanging thermal radiation with the cold universe through the transparent atmospheric window. Spectrum tailoring of the radiative cooler is the key to daytime radiative cooling in previously reported works. In addition, radiative coolers with large-scale fabrication and self-cleaning characteristics should be further developed to improve their industrial applicability. Herein, we propose a bilayer radiative cooling coating with the superhydrophobic property and a scalable process, by covering TiO2/acrylic resin paint with a silica/poly(vinylidene fluoride-co-hexafluoropropylene) (SiO2/P(VdF-HFP)) composite masking layer. The strong Mie scattering in TiO2/acrylic resin paint contributes to high solar reflection, while the SiO2/P(VdF-HFP) masking layer is responsible for superhydrophobicity and synergetic solar reflection in the ultraviolet band, resulting in an effective solar reflectivity of 94.0 % with an average emissivity of 97.1 % and superhydrophobicity with a water contact angle of 158.9°. Moreover, the as-fabricated coating can be cooled to nearly 5.8 °C below the temperature of commercial white paint and 2.7 °C below the local ambient temperature under average solar irradiance of over 700 W m−2. In addition, yearly energy saving of 29.0 %–55.9 % can be achieved after the coating is applied to buildings in Phoenix, Hong Kong, Singapore, Guangzhou, and Riyadh. |
| first_indexed | 2024-04-24T22:52:29Z |
| format | Article |
| id | doaj.art-526f7e2d322c40c7aa576249b8b4c792 |
| institution | Directory Open Access Journal |
| issn | 2192-8614 |
| language | English |
| last_indexed | 2025-02-18T02:48:26Z |
| publishDate | 2023-10-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | Nanophotonics |
| spelling | doaj.art-526f7e2d322c40c7aa576249b8b4c7922024-11-25T11:19:10ZengDe GruyterNanophotonics2192-86142023-10-0113558359110.1515/nanoph-2023-0511Superhydrophobic bilayer coating for passive daytime radiative coolingZhao Bin0Xu Chengfeng1Jin Cheng2Lu Kegui3Chen Ken4Li Xiansheng5Li Lanxin6Pei Gang7Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei230027, ChinaDepartment of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei230027, ChinaDepartment of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei230027, ChinaDepartment of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei230027, ChinaDepartment of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei230027, ChinaDepartment of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei230027, ChinaDepartment of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei230027, ChinaDepartment of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei230027, ChinaPassive radiative cooling is an energy-free cooling method by exchanging thermal radiation with the cold universe through the transparent atmospheric window. Spectrum tailoring of the radiative cooler is the key to daytime radiative cooling in previously reported works. In addition, radiative coolers with large-scale fabrication and self-cleaning characteristics should be further developed to improve their industrial applicability. Herein, we propose a bilayer radiative cooling coating with the superhydrophobic property and a scalable process, by covering TiO2/acrylic resin paint with a silica/poly(vinylidene fluoride-co-hexafluoropropylene) (SiO2/P(VdF-HFP)) composite masking layer. The strong Mie scattering in TiO2/acrylic resin paint contributes to high solar reflection, while the SiO2/P(VdF-HFP) masking layer is responsible for superhydrophobicity and synergetic solar reflection in the ultraviolet band, resulting in an effective solar reflectivity of 94.0 % with an average emissivity of 97.1 % and superhydrophobicity with a water contact angle of 158.9°. Moreover, the as-fabricated coating can be cooled to nearly 5.8 °C below the temperature of commercial white paint and 2.7 °C below the local ambient temperature under average solar irradiance of over 700 W m−2. In addition, yearly energy saving of 29.0 %–55.9 % can be achieved after the coating is applied to buildings in Phoenix, Hong Kong, Singapore, Guangzhou, and Riyadh.https://doi.org/10.1515/nanoph-2023-0511radiative coolingsuperhydrophobicitysynergetic reflectionatmospheric window |
| spellingShingle | Zhao Bin Xu Chengfeng Jin Cheng Lu Kegui Chen Ken Li Xiansheng Li Lanxin Pei Gang Superhydrophobic bilayer coating for passive daytime radiative cooling Nanophotonics radiative cooling superhydrophobicity synergetic reflection atmospheric window |
| title | Superhydrophobic bilayer coating for passive daytime radiative cooling |
| title_full | Superhydrophobic bilayer coating for passive daytime radiative cooling |
| title_fullStr | Superhydrophobic bilayer coating for passive daytime radiative cooling |
| title_full_unstemmed | Superhydrophobic bilayer coating for passive daytime radiative cooling |
| title_short | Superhydrophobic bilayer coating for passive daytime radiative cooling |
| title_sort | superhydrophobic bilayer coating for passive daytime radiative cooling |
| topic | radiative cooling superhydrophobicity synergetic reflection atmospheric window |
| url | https://doi.org/10.1515/nanoph-2023-0511 |
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