Cooling polymer coating permits energy-free rooftop water assortment
by Simon Mansfield
Sydney, Australia (SPX) Nov 04, 2025
Researchers from the College of Sydney and Dewpoint Improvements have engineered a nano-porous polymer coating that passively cools constructing surfaces and permits atmospheric water assortment with out power enter. The fabric, composed of PVDF-HFP, displays as much as 97 p.c of daylight, radiates warmth, and lowers coated floor temperatures by as a lot as six levels Celsius in comparison with ambient air. This cooling permits water vapor within the air to condense on the coating and kind droplets.
Out of doors assessments carried out on the Sydney Nanoscience Hub rooftop demonstrated dew seize on 32 p.c of days over six months, with every sq. meter of coated floor in a position to gather as much as 390 milliliters of water day by day below optimum situations. A 12-square-meter rooftop may thus meet the ingesting water wants of 1 particular person per day. The expertise is suited to functions in horticulture, livestock care, cooling, and hydrogen manufacturing, which requires 9 liters of water per kilogram produced. Scaling up assortment areas may present water assets to distant or industrial areas.
Not like conventional white paints that depend on titanium dioxide, the porous PVDF-HFP coating achieves excessive reflectivity by its construction relatively than UV pigments. In accordance with Dewpoint Improvements CTO Dr Ming Chiu, the fabric avoids glare by diffusing mild and stays strong below extended direct daylight. Sturdiness assessments confirmed no proof of degradation.
The expertise additionally affords potential advantages in lowering city warmth island impacts and decreasing air-conditioning power calls for. Dew formation was detected in arid areas as effectively, supplied that night-time humidity elevated above a threshold, and the tactic is meant to complement, not exchange, rainwater. Dewpoint Improvements is growing a water-based formulation to allow easy rooftop utility utilizing rollers or sprayers. With rainwater techniques current in additional than two million Australian properties, the dew-coating may add supplementary water provide.
The innovation was licensed by Dewpoint Improvements in 2022 from the College of Sydney and is now transferring into business improvement geared toward broader use in housing, agriculture, and infrastructure designed for local weather resilience.
Analysis Report:Passively cooled paint-like coatings for atmospheric water seize
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