The latest innovation in the fight against global warming comes from Purdue University, where researchers have developed an ultra-white paint that reflects 99% of all light. This paint is not only whiter than any currently available in the market, but it also keeps surfaces cooler, making it a potential game-changer in reflecting sunlight and combating heat.
The Revolutionary Ultra-White Paint
The groundbreaking ultra-white paint developed by Purdue University scientists differs significantly from typical commercial white paint, which tends to get warmer rather than cooler. Current paints on the market reflect only 80-90% of sunlight, thus failing to cool surfaces below their surroundings. The novel ultra-white paint bounces back 99% of all light, staying exceptionally cooler than the ambient temperature, even under direct sunlight.
Unlike older formulations made of calcium carbonate, this new paint is produced using barium sulfate, a compound used to give photo paper and cosmetics a white colour. Different particle sizes of barium sulfate scatter varying amounts of light, allowing a broad spectrum of light reflection and resulting in the highest reflectance.
A Rival for Vantablack
Vantablack, the blackest black paint, absorbs 99.9% of visible light and plays a crucial role in the functioning of high-performance infrared cameras, sensors, and satellite calibration sources. As the ultra-white paint is to reflection, Vantablack is to absorption. The ability of this black paint to absorb light energy and transform it into heat has promising implications for solar power development.
How Objects Absorb or Reflect Light
Objects are perceived because they either absorb or reflect light, composed of seven different colours (VIBGYOR). Each colour represents a different light wavelength. The colour of an object is determined by the wavelength that its molecules fail to absorb. For instance, a green sofa appears so because all colours except green are absorbed by the material, reflecting only green light. Conversely, a black object absorbs all light wavelengths, reflecting none and therefore appearing black. Dark objects tend to absorb more heat because the absorbed light energy is transformed into heat energy.
Impact of the Ultra-White Paint
This novel paint technology promises to maintain buildings cooler, mitigating the Urban Heat Island effect. It could significantly aid the fight against global warming by decreasing dependence on electrically powered air conditioning, which contributes to atmospheric heat in multiple ways. Air conditioning not only ejects hot air from buildings but also generates heat when operating and often uses fossil fuel-generated electricity, further increasing carbon dioxide emissions. The new paint could inhibit heat-related ailments and prevent water quality degradation caused by heated ground.
India’s Cooling Action Plan
India has inked one of the world’s pioneering Cooling Action plans, envisioning strategies to address cooling needs across sectors and measures to reduce cooling demand.
Adapting to a Warmer Planet
With climate change elevating temperatures and urbanisation worsening global warming, it’s crucial to devise strategies for reducing and combatting heat stress. Key steps include enhancing the efficiency of cooling appliances, proposing better building design for natural cooling, promoting renewable energy-based cold chains, and investing in research for environmentally-friendly refrigerant gases. Urban spaces can incorporate small green infrastructures, greener rooftops, and light-coloured concrete, all of which reflect more sunlight and absorb less heat.
