Water-Resistant Poly(ethylene oxide) Electrospun Membranes Enabled by In Situ UV-Cross-Linking for Efficient Daytime...

Area of Science:

• Materials Science
• Nanotechnology
• Sustainable Energy

Background:

• Daytime radiative cooling offers a zero-energy, eco-friendly cooling solution by reflecting sunlight and emitting heat through atmospheric windows.
• Poly(ethylene oxide) (PEO) electrospun membranes exhibit excellent radiative cooling properties due to selective infrared emission and solar reflectance.
• The high water solubility of PEO membranes limits their application in outdoor conditions prone to rain.

Purpose of the Study:

• To develop water-resistant PEO electrospun membranes for robust daytime radiative cooling applications.
• To overcome the water sensitivity limitation of PEO-based radiative cooling materials.

Main Methods:

• Synthesized acrylate-terminated PEO and prepared an electrospinning solution with cross-linking agents and photoinitiators.
• Employed an in situ UV-crosslinking strategy during electrospinning to create water-resistant PEO nanofibers.
• Characterized the membranes' optical properties (solar reflectance, infrared emissivity) and water resistance.

Main Results:

• The cross-linked PEO membranes achieved high solar reflectance (89.6%) and infrared emissivity (96.3% in 8-13 μm).
• The membranes demonstrated excellent water resistance, with minimal morphological changes after prolonged water soaking.
• Outdoor tests showed significant temperature drops (13.8 °C before water soaking, 11.5 °C after) compared to ambient air temperature.

Conclusions:

• The in situ UV-crosslinking strategy successfully imparts water resistance to PEO electrospun membranes.
• These water-resistant PEO membranes maintain effective radiative cooling performance, even after water exposure.
• The developed membranes show potential for real-world applications in outdoor daytime radiative cooling systems.