Melt-Processed, One-Step, In Situ Hierarchically Structured Porous Polymer Nanocomposite for Radiative Cooling in Hot...

Area of Science:

• Materials Science
• Nanotechnology
• Sustainable Energy

Background:

• Porous polymeric composites are key for passive radiative cooling.
• Challenges include solvent use and nanoparticle dispersion in eco-friendly fabrication.

Purpose of the Study:

• To develop a solvent-free, eco-friendly method for creating porous polymer nanocomposites with hierarchical structures.
• To enhance solar reflectance and mid-infrared emissivity for effective radiative cooling.

Main Methods:

• Utilizing sodium bicarbonate's thermal decomposition during melt processing to form micropores and disperse nanoparticles.
• Fabricating porous polymer nanocomposites (FPCS) via a universal melt processing technique.

Main Results:

• FPCS exhibit high solar reflectance (94.2%) and mid-infrared emissivity (94.5%).
• Achieved sub-ambient cooling of ~6.8°C during the day and ~2.0°C under hot weather (>52°C).
• Demonstrated efficient sub-ambient cooling even in sub-zero environments.

Conclusions:

• Presents a straightforward, feasible, and eco-friendly approach for high-performance radiative cooling materials.
• FPCS show significant potential for building energy conservation, cooling water, and mitigating extreme heat.