Hierarchical Porous Polymer Coatings Based on UV-Curing for Highly Efficient Passive All-Day Radiative Cooling

Passive radiative cooling provides a promising way to reduce energy consumption for cooling. However, it always requires stringent materials designs or manipulations, which are neither cost-effective nor widely adaptable. Here, we report a fast, inexpensive, and scalable UV-curing method to fabricate porous polymer coatings via photopolymerization-induced phase separation. This coating with hierarchical pore structure, has a superior long-wave infrared emittance of 0.98 and strong solar reflectance of 0.96, resulting in subambient temperature drops of similar to 9.8 degrees C during the night and similar to 5.7 degrees C under solar intensity of similar to 960 W m(-2) in the metropolitan area in summer. Moreover, the UV-cured coating is highly cross-linked and superhydrophobic without any treatment, showing excellent durability after long-term UV irradiation, thermal aging, or immersion in corrosive chemicals. The paint-like simplicity and remarkable weather resistance are vital for promoting practical applications of cooling coatings.

Automated summary

This article presents a fast, inexpensive, and scalable UV-curing method to fabricate porous polymer coatings with superior infrared emittance and solar reflectance, resulting in significant temperature drops during the night and under solar intensity in the metropolitan area in summer. The UV-cured coating is highly cross-linked and superhydrophobic, showing excellent durability after long-term UV irradiation, thermal aging, or immersion in corrosive chemicals.