High Performance Radiative Cooling Coating with Dense Surface Structure via Closed-Cell Microstructures and Uniformly...

Area of Science:

• Materials Science
• Sustainable Energy

Background:

• Passive daytime radiative cooling (PDRC) coatings are crucial for sustainable building thermal management.
• Achieving high solar reflectance and long-term durability simultaneously remains a significant challenge for PDRC adoption.

Purpose of the Study:

• To develop a novel PDRC coating strategy that enhances both solar reflectance and durability.
• To address the limitations of TiO2 agglomeration and improve light scattering in waterborne PDRC coatings.

Main Methods:

• Utilized a rheology-based method to reduce TiO2 agglomeration and enhance Mie scattering in waterborne coatings.
• Incorporated closed-cell microstructures to augment light scattering and preserve surface integrity.

Main Results:

• Achieved high infrared emissivity (94.9%) and solar reflectance (90.8%).
• Demonstrated a significant daytime cooling effect of 7.63 °C under direct sunlight.
• Confirmed exceptional outdoor performance including robust adhesion, thermal stability, and resistance to acid/alkali, UV, and fouling.

Conclusions:

• The novel PDRC coating strategy effectively balances high performance with long-term durability.
• The developed coating is low-cost, scalable, and suitable for widespread building applications.
• This technology offers a promising solution for reducing building cooling energy consumption and carbon emissions.