The "Whitest Paint" you’re referring to is likely BaSO₄-based ultra-white paint developed by researchers at Purdue University—a material engineered to reflect unprecedented amounts of sunlight and dramatically cool surfaces without the need for air conditioning.
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🧪 What is the Whitest Paint?
It’s a barium sulfate (BaSO₄)-based paint that reflects up to 98.1% of sunlight.
This is significantly higher than commercial white paints, which typically reflect around 80%–90%.
The paint also emits infrared heat efficiently, radiating heat away even under direct sun.
🌡️ How Does It Work?
1. High Solar Reflectance: The barium sulfate particles are highly reflective across the entire solar spectrum.
2. Radiative Cooling: The paint sends infrared heat into space through the Earth's atmospheric window (8–13 microns), achieving surface temperatures below ambient air temperature—even in full sun.
3. Particle Size Optimization: Multiple particle sizes of BaSO₄ scatter light more effectively, boosting reflectivity.
🏆 Key Achievements:
Guinness World Record (2021) for the whitest paint ever created.
Tested to cool surfaces by up to 10°C (18°F) below ambient under peak sun.
Can potentially reduce cooling costs by up to 40% in some climates.
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🌍 Applications & Impact:
Buildings: Coating rooftops and facades to passively cool structures.
Vehicles: Potential for cars, trucks, and aircraft to reflect heat and reduce AC loads.
Urban Heat Mitigation: Could significantly lower the Urban Heat Island effect in cities.
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⚙️ Practical Considerations:
Factor Details
Color Ultra-white; limited color options.
Durability Early versions—still under long-term testing.
Cost & Availability Not yet commercially mass-produced. Likely high initial cost.
Environmental Safety Non-toxic material (BaSO₄ is used in medical imaging too).
