Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > MIT engineers develop 'blackest black' material to date: Made from carbon nanotubes, the new coating is 10 times darker than other very black materials

MIT engineers have cooked up a material made of carbon nanotubes that is 10 times blacker than anything that has previously been reported.

CREDIT
R. Capanna, A. Berlato, and A. Pinato
MIT engineers have cooked up a material made of carbon nanotubes that is 10 times blacker than anything that has previously been reported. CREDIT R. Capanna, A. Berlato, and A. Pinato

Abstract:
With apologies to "Spinal Tap," it appears that black can, indeed, get more black.

MIT engineers report today that they have cooked up a material that is 10 times blacker than anything that has previously been reported. The material is made from vertically aligned carbon nanotubes, or CNTs -- microscopic filaments of carbon, like a fuzzy forest of tiny trees, that the team grew on a surface of chlorine-etched aluminum foil. The foil captures more than 99.96 percent of any incoming light, making it the blackest material on record.

MIT engineers develop 'blackest black' material to date: Made from carbon nanotubes, the new coating is 10 times darker than other very black materials

Cambridge, MA | Posted on September 13th, 2019

The researchers have published their findings today in the journal ACS-Applied Materials and Interfaces. They are also showcasing the cloak-like material as part of a new exhibit today at the New York Stock Exchange, titled "The Redemption of Vanity."

The artwork, a collaboration between Brian Wardle, professor of aeronautics and astronautics at MIT, and his group, and MIT artist-in-residence Diemut Strebe, features a 16.78-carat natural yellow diamond, estimated to be worth $2 million, which the team coated with the new, ultrablack CNT material. The effect is arresting: The gem, normally brilliantly faceted, appears as a flat, black void.

Wardle says the CNT material, aside from making an artistic statement, may also be of practical use, for instance in optical blinders that reduce unwanted glare, to help space telescopes spot orbiting exoplanets.

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

Wardle's co-author on the paper is former MIT postdoc Kehang Cui, now a professor at Shanghai Jiao Tong University.

Into the void

Wardle and Cui didn't intend to engineer an ultrablack material. Instead, they were experimenting with ways to grow carbon nanotubes on electrically conducting materials such as aluminum, to boost their electrical and thermal properties.

But in attempting to grow CNTs on aluminum, Cui ran up against a barrier, literally: an ever-present layer of oxide that coats aluminum when it is exposed to air. This oxide layer acts as an insulator, blocking rather than conducting electricity and heat. As he cast about for ways to remove aluminum's oxide layer, Cui found a solution in salt, or sodium chloride.

At the time, Wardle's group was using salt and other pantry products, such as baking soda and detergent, to grow carbon nanotubes. In their tests with salt, Cui noticed that chloride ions were eating away at aluminum's surface and dissolving its oxide layer.

"This etching process is common for many metals," Cui says. "For instance, ships suffer from corrosion of chlorine-based ocean water. Now we're using this process to our advantage."

Cui found that if he soaked aluminum foil in saltwater, he could remove the oxide layer. He then transferred the foil to an oxygen-free environment to prevent reoxidation, and finally, placed the etched aluminum in an oven, where the group carried out techniques to grow carbon nanotubes via a process called chemical vapor deposition.

By removing the oxide layer, the researchers were able to grow carbon nanotubes on aluminum, at much lower temperatures than they otherwise would, by about 100 degrees Celsius. They also saw that the combination of CNTs on aluminum significantly enhanced the material's thermal and electrical properties -- a finding that they expected.

What surprised them was the material's color.

"I remember noticing how black it was before growing carbon nanotubes on it, and then after growth, it looked even darker," Cui recalls. "So I thought I should measure the optical reflectance of the sample.

"Our group does not usually focus on optical properties of materials, but this work was going on at the same time as our art-science collaborations with Diemut, so art influenced science in this case," says Wardle.

Wardle and Cui, who have applied for a patent on the technology, are making the new CNT process freely available to any artist to use for a noncommercial art project.

"Built to take abuse"

Cui measured the amount of light reflected by the material, not just from directly overhead, but also from every other possible angle. The results showed that the material absorbed greater than 99.995 percent of incoming light, from every angle. In essence, if the material contained bumps or ridges, or features of any kind, no matter what angle it was viewed from, these features would be invisible, obscured in a void of black.

The researchers aren't entirely sure of the mechanism contributing to the material's opacity, but they suspect that it may have something to do with the combination of etched aluminum, which is somewhat blackened, with the carbon nanotubes. Scientists believe that forests of carbon nanotubes can trap and convert most incoming light to heat, reflecting very little of it back out as light, thereby giving CNTs a particularly black shade.

"CNT forests of different varieties are known to be extremely black, but there is a lack of mechanistic understanding as to why this material is the blackest. That needs further study," Wardle says.

####

For more information, please click here

Contacts:
Sarah McDonnell

617-827-7637

Copyright © Massachusetts Institute of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

An EPiQS Pursuit: Physicist Andrea Young is chosen to receive an Experimental Investigator award from the Moore Foundation May 28th, 2020

Study finds electrical fields can throw a curveball: Particle-scale phenomenon akin to the swerving of a curveball could allow selective separation of suspended nanomaterials May 26th, 2020

Surrey reveals its implantable biosensor that operates without batteries May 22nd, 2020

Researchers demonstrate transport of mechanical energy, even through damaged pathways: Topological pump can provide stability for communication technologies May 22nd, 2020

Possible Futures

An EPiQS Pursuit: Physicist Andrea Young is chosen to receive an Experimental Investigator award from the Moore Foundation May 28th, 2020

Study finds electrical fields can throw a curveball: Particle-scale phenomenon akin to the swerving of a curveball could allow selective separation of suspended nanomaterials May 26th, 2020

Visualization of functional components to characterize optimal composite electrodes May 22nd, 2020

Researchers demonstrate transport of mechanical energy, even through damaged pathways: Topological pump can provide stability for communication technologies May 22nd, 2020

Nanotubes/Buckyballs/Fullerenes/Nanorods

Oil & gas and automotive sectors will benefit from durable polymers with graphene nanotubes May 14th, 2020

OCSiAl becomes the largest European supplier of single wall carbon nanotubes with its upgraded REACH registration April 23rd, 2020

Double-walled nanotubes have electro-optical advantages :Rice University calculations show they could be highly useful for solar panels March 27th, 2020

Groovy key to nanotubes in 2D: Why do carbon nanotubes line up? They're in a groove March 16th, 2020

Discoveries

Study finds electrical fields can throw a curveball: Particle-scale phenomenon akin to the swerving of a curveball could allow selective separation of suspended nanomaterials May 26th, 2020

MSU scientists solve half-century-old magnesium dimer mystery May 22nd, 2020

Researchers review advances in 3D printing of high-entropy alloys: SUTD collaborates with universities in Singapore and China to shine light on HEA manufacturing processes and inspire further research in this emerging field May 22nd, 2020

A stitch in time: How a quantum physicist invented new code from old tricks: Error suppression opens pathway to universal quantum computing May 22nd, 2020

Materials/Metamaterials

An EPiQS Pursuit: Physicist Andrea Young is chosen to receive an Experimental Investigator award from the Moore Foundation May 28th, 2020

Study finds electrical fields can throw a curveball: Particle-scale phenomenon akin to the swerving of a curveball could allow selective separation of suspended nanomaterials May 26th, 2020

Researchers review advances in 3D printing of high-entropy alloys: SUTD collaborates with universities in Singapore and China to shine light on HEA manufacturing processes and inspire further research in this emerging field May 22nd, 2020

Researchers demonstrate transport of mechanical energy, even through damaged pathways: Topological pump can provide stability for communication technologies May 22nd, 2020

Announcements

An EPiQS Pursuit: Physicist Andrea Young is chosen to receive an Experimental Investigator award from the Moore Foundation May 28th, 2020

Study finds electrical fields can throw a curveball: Particle-scale phenomenon akin to the swerving of a curveball could allow selective separation of suspended nanomaterials May 26th, 2020

Visualization of functional components to characterize optimal composite electrodes May 22nd, 2020

Researchers demonstrate transport of mechanical energy, even through damaged pathways: Topological pump can provide stability for communication technologies May 22nd, 2020

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Study finds electrical fields can throw a curveball: Particle-scale phenomenon akin to the swerving of a curveball could allow selective separation of suspended nanomaterials May 26th, 2020

Surrey reveals its implantable biosensor that operates without batteries May 22nd, 2020

Visualization of functional components to characterize optimal composite electrodes May 22nd, 2020

Researchers demonstrate transport of mechanical energy, even through damaged pathways: Topological pump can provide stability for communication technologies May 22nd, 2020

Patents/IP/Tech Transfer/Licensing

A new study published on the cover of Science could bolster the development of batteries, fuel cells, 3D printing technologies and more May 1st, 2020

New green technology from UMass Amherst generates electricity 'out of thin air' Renewable device could help mitigate climate change, power medical devices February 17th, 2020

The Wave of the Future: Researchers achieve first successful generation and detection of pure spin currents in antiferromagnetic materials January 29th, 2020

Supercharging tomorrow: Monash develops world's most efficient lithium-sulfur battery January 3rd, 2020

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project