The darkest black ever created by MIT scientists, captures more than 99.99% of the light

Scientists from the Massachusetts Institute of Technology (MIT) have unveiled the darkest black ever produced at an art show in New York. The material, which is 10 times blacker than anything previously reported, consists of carbon nanotubes (CNTs) and removes more than 99.99% of the light.

This feat was achieved by chance: the team of engineers had experimented with different ways to create CNTs. They are extremely thin carbon tubes, powerful and excellent conductors of heat and electricity – properties that make them very interesting for scientists.

Brian Wardle's team at MIT had attempted to produce CNT on aluminum when it had reached an obstacle. They discovered that an oxide layer would coat aluminum as soon as it would be exposed to air – and this layer prevented it from driving heat and heat. # 39; electricity. Wardle and his colleagues used salt to dissolve the oxide layer.

After removing it, the aluminum was transferred to an oxygen-free environment and then placed in an oven to grow the nanotubes. The first results showed that the thermal and electrical properties of the material were considerably improved. They also noticed something unexpected, however: the color of the material.

At this point, they noticed how dark the material was. "I remember noticing how black it was before growing carbon nanotubes, and then after growing it looked even darker, so I thought I had to measure reflectivity optical sample, "said Kehang Cui, currently at Shanghai Jiao Tong University. , China, said in a statement.

Measurements showed that the material absorbed more than 99.995% of incoming light from all angles. "Anything covered with this CNT material loses all its plasticity and appears entirely flat, abbreviated / reduced to a black silhouette," said Diemut Strebe, the artist who collaborated with MIT scientists, in a statement.

Strebe and the MIT team unveiled the material at an exhibition titled The Redemption of Vanity on the New York Stock Exchange. In this document, the team concealed a 16.78 carat natural yellow diamond in the material to show how it had disappeared into the darkness. Diamonds, which are also carbon, are one of the best light reflectors on Earth. "Because of the extremely high light absorption qualities of NTCs, any object, in this case a big diamond coated with NTC, becomes a kind of black hole without shadow," said Strebe.

Scientists do not know why the material is so black, but believe that there may be a connection between the CNTs and the way the aluminum is etched. "We know that CNT forests of different varieties are extremely black, but we do not understand enough why this material is the darkest, which requires further study," Wardle said.

The conclusions of Wardle and Cui are published in the journal Materials applied by the ACS.

MIT engineers believe that the ultra-dark material could have practical applications in telescopes, helping to reduce glare while looking in space.

"There are optical and space science applications for very black materials, and of course, artists are interested in black, which goes back well before the Renaissance," Wardle said. "Our material is 10 times darker than anything that has ever been reported, but I think the blackest black is a constantly moving target.Someone will find a darker material and will eventually understand all the mechanisms underlying and will be able to engineer the ultimate black. "