American researchers have developed a paint so the reflective ability is more than exceptional. This is the whitest paint in existence. According to the researchers, this would be more efficient than an air conditioner and could act in favor of the fight against global warming.
In 2019, scientists from MIT presented their latest creation, the darkest material in the world. Capable of absorbing over 99.96% of incoming light, this material is made of carbon nanotubes. In a statement of April 15, 2021, Purdue University (United States) presents the whitest paint in the world. The objective of this innovation is none other than the fight against global warming.
Xiulin Ruan, professor of mechanical engineering and main author of the work, explains that the substance consists of barium sulfate (forest4) in great concentration. This material is commonly used for bleaching cosmetics as well as photo paper. According to the results of the last tests, the paint in question reflects up to 98.1% of sunlight. Six months ago, these tests showed a slightly lower capacity, namely 95.5%.
The study published in Applied materials and ACS interfaces reports an average cooling capacity of 117 W / m². Thus, the painting remains at more than 4.5 ° C below ambient temperature. Currently, classic white paints reflect between 80% and 90% of sunlight. Thus, they cannot make surfaces cooler than their surroundings.
Xiulin Ruan and his team are convinced that their painting could integrate the fight for the climate. According to them, the ideal would be to paint 1% of the earth’s surface with this ultra-white paint. Remember that the surface area of submerged land is 148 million km ², or 29% of the surface area of the earth (510.1 million km ² in all). Thus, the researchers recommend painting a area of 5.1 million km², or the equivalent of half of the European continent. According to them, this surface could be an uninhabited area covered with rocks. However, it is very difficult to imagine painting such a large area.
The paint in question could also be used in the building sector. This would save energy by limiting the use of air conditioning systems, especially in hot countries. Remember that air conditioners and other fans represent 10% of world consumption electricity, a value that could reach 40% in 2050.
The researchers estimate that painting a roof area of about 90 m² would provide a 10 kW cooling power. However, this value is more important than the performance achieved by most air conditioners. Now, scientists are working on another very important point: reducing the cost of manufacturing this paint and approaching that of conventional paints.