Ultra white: Researchers at Purdue University in the USA have developed an ink that will help fight global warming. The ultra white dye can be used in buildings and thus reflect sunlight and radiate infrared heat.
More than that, it can keep surfaces cooler than room temperature. According to the inventors, the paint is able to cool the buildings to the point of dispensing with the use of air conditioning – reducing carbon emissions.
In the tests carried out by the researchers, the ultra white dye was able to reflect 98.1% of sunlight. In this way, it is able to cool the surfaces to 4.5ºC below room temperature.
Typically, white inks designed to repel heat only reflect 80% to 90% of the light. In addition, they are not designed to make surfaces cooler than the environment.
“If you use this paint to cover a roof of about 90 square meters, it will have a cooling power of 10 kilowatts. This is more powerful than central air conditioners in most homes, ”explains Xiulin Ruan, professor of engineering at Purdue.
The secret to cooling
The secret of the ultra white dye is barium sulfate. With varying sizes, the high concentration of particles of the chemical compound gives the ink the widest spectral dispersion and contributes to increase the reflection factor.
“We analyzed several commercial products, basically anything white. We found that, using barium sulfate, you can theoretically make things much more reflective and whiter than they are, ”explains researcher Xiangyu Li.
The fruit of six years of research, the dye has already undergone several tests and proved to be more resistant than the paints available on the market. So, the researchers have already submitted a patent application to the Technology Commercialization Office.