Durable Self-Cleaning Radiative Cooling Coatings for Building Energy Efficiency
Huiquan Ju1, Haibin Long1, Shasha Yang1
1School of Materials Engineering, Jiangsu University of Technology, Changzhou 213001, P. R. China.
ACS Applied Materials & Interfaces
|June 13, 2024
Summary
This study developed a practical passive daytime radiative cooling (PDRC) coating using modified calcined kaolin. The durable, superhydrophobic coating offers significant cooling effects and energy savings, demonstrating excellent scalability for building applications.
Area of Science:
- Materials Science
- Nanotechnology
- Sustainable Energy
Background:
- Passive daytime radiative cooling (PDRC) is a promising energy-saving technology.
- Existing PDRC coatings often lack practical features like durability and scalability.
- There is a need for PDRC materials that balance high performance with real-world applicability.
Purpose of the Study:
- To develop a highly practical PDRC coating with enhanced durability and scalability.
- To investigate the performance of a modified calcined kaolin-based coating for PDRC applications.
- To evaluate the cooling performance, durability, and energy-saving potential of the developed coating.
Main Methods:
- Preparation of a modified calcined kaolin/(ethylene trifluorochloroethylene copolymer-polydimethylsiloxane) (MK/(FEVE-PDMS)) coating.
- Characterization of optical properties (solar reflectivity, infrared emissivity), superhydrophobicity (contact angles), and adhesion strength.
- Evaluation of cooling performance under solar irradiance and assessment of durability against UV aging and mechanical damage.
Main Results:
- The MK/(FEVE-PDMS) coating achieved high solar reflectivity (92.5%) and mid-infrared emissivity (94.6%).
- The coating exhibited superhydrophobicity (ACA: 160.2°) and achieved a temperature drop of up to 13.12 °C.
- Demonstrated excellent adhesion (class 2), durability, self-cleaning properties, and scalability with potential energy savings over 10%.
Conclusions:
- The developed MK/(FEVE-PDMS) coating offers a practical and durable solution for passive daytime radiative cooling.
- Its combination of high performance, superhydrophobicity, and scalability makes it suitable for widespread building applications.
- The coating shows significant potential for reducing cooling energy consumption in hot climates.
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