2025-02-05 ペンシルベニア州立大学（PennState）
The PMMA sheets fabricated by materials science researchers are white and porous, making them a suitable material for covering buildings for passive daytime cooling. Credit: Provided by Yupeng Li/Dalian University of Technology. All Rights Reserved.
＜関連情報＞
- https://www.psu.edu/news/engineering/story/porous-plastic-sheets-can-cool-buildings-radiating-light-space
- https://advanced.onlinelibrary.wiley.com/doi/10.1002/admt.202400713
日中の受動的放射冷却のための最適な細孔パラメータを有する粉末焼結階層的多孔質PMMA Powder-Sintered Hierarchically Porous PMMA with Optimal Pore Parameters for Passive Daytime Radiative Cooling
Yupeng Li, Hui Zhao, Xiangren Meng, Yishu Zhao, Haodong Liu, Mingkai Lei, Akhlesh Lakhtakia
Advanced Materials Technologies Published: 05 November 2024
DOI:https://doi.org/10.1002/admt.202400713
Abstract
Porous radiative cooling polymers have drawn significant attention for passive daytime cooling due to their desirable cooling performance and easy scalability. Since optimal pore parameters (i.e., pore diameter and porosity) will enhance light scattering, polymethyl methacrylate (PMMA) powders are sintered to fabricate samples with different pore parameters by the one-step full-dry powder sintering method. These samples have a hierarchically porous structure with pore diameters <5.0 µm. The most porous sample has 43% porosity, 0.964 reflectance in the 0.3–2.5 µm wavelength range, and 0.967 emittance in 8–13 µm wavelength range (which is the atmospheric window). The measured cooling temperature difference decreases when the porosity is low for hierarchically porous PMMA with similar pore size distribution. The high sub-ambient cooling temperature reduction provided by hierarchically porous PMMA with optimal pore parameters is due to high solar reflectance when illuminated by the sun. Similar cooling trends are evident when sunlight is simulated by a Xenon lamp and an optical filter. The powder-sintered hierarchically porous PMMA with optimal pore parameters can be an excellent radiative cooler for passive daytime cooling applications.
