Inventing ultra-light gold material like ... air

For a long time, "light as a feather" is not a phrase that characterizes gold. However, scientists have created a new, ultra-light form of this precious metal, using materials containing up to 98% air.

Produce light yellow material like air

This particular type of gold is made up of milk protein fibers . And although it looks like pure gold, it is light enough to float on top of milk coffee.

Raffaele Mezzenga, professor of food and light materials, is the inventor of this golden foam, 3D grid structure . "It is also called an airgel , 1,000 times lighter than conventional gold alloys. It is also lighter than water and almost light on air," said Mezzenga.

Airgel possesses the same color and brightness as real gold, making it easy for anyone to mistakenly glance at it. However, it is soft and can be molded.

To create new types of gold, the researchers developed the material by heating milk proteins until they produced smooth nanoscale protein fibers (1 nanometer = 1 / billionth of a meter), then for all. into a gold salt solution. This led to the formation of a gel-like network of gold fibers - airgel.

Dr. Gustav Nyström, a member of Professor Mezzenga's research team, revealed that one of their biggest challenges was drying the airgel network without destroying it. Eventually, they used a gentle, elaborate drying process with carbon dioxide to achieve the goal, because air drying can destroy ultralight gold.

All the process used by the team to crystallize gold particles is completely new. This method has made it much easier to create a homogeneous aerogel, perfectly matched with gold alloys.

Through the application of the new method, scientists are more likely to affect the characteristics of gold in a simpler way."The optical properties of gold depend heavily on the size and shape of the gold particles. Therefore, we can even change the color of the material. When we change the reaction conditions to causing gold to become incoherent into tiny particles, but also smaller to nanometer size, the result will be dark red gold , " explained Mr. Nyström.

Special structure makes light yellow airgel close to air.(Photo: Daily Mail).

Experts can not only change the color of the material, but also change its other properties, such as absorption and reflection. Professor Mezzenga believes that the golden aerogel can also be used in other applications, such as in the manufacture of watches and jewelry or the catalyst chemical reactions for catalysts or in the production of sensors Pressure.

Mr. Mezzenga took for example that, at normal air pressure, the individual gold particles in the golden airgel do not come into contact with each other and the golden airgel does not conduct electricity. But when the pressure increased, the material was compressed and the particles began to collide with each other, causing the yellow airgel to conduct electricity.