Recyclable Dry-Processed PTFE Composite Films for Passive Radiative Cooling With Interfacial Energy Harvesting

Area of Science:

• Materials Science
• Sustainable Technologies
• Nanotechnology

Background:

• Passive radiative cooling (PRC) offers electricity-free cooling but often relies on unsustainable solvent-based methods.
• Volatile organic compounds (VOCs) and solvent waste are significant environmental concerns in current PRC material production.

Purpose of the Study:

• To develop a sustainable, dry-processed material for passive radiative cooling (PRC).
• To create a recyclable PRC material with dual functionality for cooling and energy harvesting.
• To enhance the environmental compatibility of PRC technologies.

Main Methods:

• Utilized in situ polytetrafluoroethylene (PTFE) fibrillation to create an entangled fibril-micro/nanoparticle network.
• Fabricated a hierarchical photonic architecture via dry processing.
• Integrated the PRC film with a solid-liquid triboelectric nanogenerator (TENG) for raindrop energy harvesting.

Main Results:

• Achieved high solar reflectance (93.3%) and mid-infrared emissivity (91.1%).
• Demonstrated significant sub-ambient cooling (5.5–10.6°C) under varying humidity.
• Obtained a peak power density of 89.85 W m⁻² from raindrop energy harvesting using the integrated TENG.
• Exhibited excellent thermal stability (>500°C), durability (540h UV aging), and recyclability.

Conclusions:

• The dry-processing strategy offers a low-carbon, recyclable, and scalable approach for advanced PRC materials.
• The developed material provides all-weather energy management solutions, combining cooling and energy harvesting.
• This work advances sustainable green technologies through innovative material design and processing.