An ancient Egyptian pigment becomes a saving solution

  

Sometimes it is not necessary to search the most sophisticated laboratories on the planet to find solutions to energy, technological or environmental challenges. For example, recently it was the Romans who taught us a lesson about the durability of concrete. The researchers discovered that, unlike the concrete produced today, whose average life is estimated at just over a century, the one used by the Roman civilization harbored a secret ingredient that allowed it to withstand the corrosion of seawater: the use of volcanic formed, among others, by a mineral called tobermorite, one of the ingredients of modern cement, and phillipsite, a mineral that favors the formation of the former when it comes into contact with salt water.

However, now it is time to look back at another of the great empires of Antiquity, the Egyptian. Specifically, towards one of its most precious pigments: the so-called Egyptian blue, which was used to represent its deities and high-level figures. But, what is special about it apart from its colorful colour? Well, it is a pigment based on copper and calcium silicate that, in fact, is considered the first synthetic pigment in history. And now it has come back to life with an innovative application: infrastructure cooling thanks to its fluorescent properties.

Egyptian blue is capable of absorbing solar radiation and reflecting it in the form of infrared radiation. This fact has been known for a long time, however, new technological research has highlighted that its effectiveness is much greater than previously believed. According to recent research by scientists at the Lawrence Berkeley National Laboratory (USA), this pigment emits almost 100% of the photons it receives in the form of infrared radiation, which represents an energy efficiency of 70%, since the corresponding photons in the infrared region contain less energy than photons in the visible range. The rest of the energy is dissipated as heat.

When it comes to avoiding heating up a house, white is one of the most used solutions, although in the case of roofs other colors are usually chosen. Therefore, Egyptian blue could be an option capable of combining the aesthetic and energetic components.