Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



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

Biology’s hardest working pigments and ‘MOFs’ might just save the climate: A range of processes that currently depend on fossil fuels but are really hard to electrify will depend on the development of genuinely clean fuels, and for that to happen, much more efficient catalysts wi July 22nd, 2022

Generating power where seawater and river water meet July 22nd, 2022

First electric nanomotor made from DNA material: Synthetic rotary motors at the nanoscale perform mechanical work July 22nd, 2022

At the water’s edge: Self-assembling 2D materials at a liquid–liquid interface: Scientists find a simple way to produce heterolayer coordination nanosheets, expanding the diversity of 2D materials July 22nd, 2022

Possible Futures

Biology’s hardest working pigments and ‘MOFs’ might just save the climate: A range of processes that currently depend on fossil fuels but are really hard to electrify will depend on the development of genuinely clean fuels, and for that to happen, much more efficient catalysts wi July 22nd, 2022

Generating power where seawater and river water meet July 22nd, 2022

First electric nanomotor made from DNA material: Synthetic rotary motors at the nanoscale perform mechanical work July 22nd, 2022

At the water’s edge: Self-assembling 2D materials at a liquid–liquid interface: Scientists find a simple way to produce heterolayer coordination nanosheets, expanding the diversity of 2D materials July 22nd, 2022

Nanotubes/Buckyballs/Fullerenes/Nanorods

Buckyballs on gold are less exotic than graphene July 22nd, 2022

Strain-sensing smart skin ready to deploy: Nanotube-embedded coating detects threats from wear and tear in large structures July 15th, 2022

Boron nitride nanotube fibers get real: Rice lab creates first heat-tolerant, stable fibers from wet-spinning process June 24th, 2022

Nanotubes: a promising solution for advanced rubber cables with 60% less conductive filler June 1st, 2022

Discoveries

HKU physicists found signatures of highly entangled quantum matter July 22nd, 2022

How different cancer cells respond to drug-delivering nanoparticles: The findings of a large-scale screen could help researchers design nanoparticles that target specific types of cancer July 22nd, 2022

The best semiconductor of them all? Researchers have found a material that can perform much better than silicon. The next step is finding practical and economic ways to make it July 22nd, 2022

Buckyballs on gold are less exotic than graphene July 22nd, 2022

Materials/Metamaterials

At the water’s edge: Self-assembling 2D materials at a liquid–liquid interface: Scientists find a simple way to produce heterolayer coordination nanosheets, expanding the diversity of 2D materials July 22nd, 2022

Strain-sensing smart skin ready to deploy: Nanotube-embedded coating detects threats from wear and tear in large structures July 15th, 2022

New protocol for assessing the safety of nanomaterials July 1st, 2022

Nanotubes: a promising solution for advanced rubber cables with 60% less conductive filler June 1st, 2022

Announcements

Quantum computer works with more than zero and one: Quantum digits unlock more computational power with fewer quantum particles July 22nd, 2022

Biology’s hardest working pigments and ‘MOFs’ might just save the climate: A range of processes that currently depend on fossil fuels but are really hard to electrify will depend on the development of genuinely clean fuels, and for that to happen, much more efficient catalysts wi July 22nd, 2022

Generating power where seawater and river water meet July 22nd, 2022

First electric nanomotor made from DNA material: Synthetic rotary motors at the nanoscale perform mechanical work July 22nd, 2022

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

Buckyballs on gold are less exotic than graphene July 22nd, 2022

Quantum computer works with more than zero and one: Quantum digits unlock more computational power with fewer quantum particles July 22nd, 2022

Biology’s hardest working pigments and ‘MOFs’ might just save the climate: A range of processes that currently depend on fossil fuels but are really hard to electrify will depend on the development of genuinely clean fuels, and for that to happen, much more efficient catalysts wi July 22nd, 2022

Generating power where seawater and river water meet July 22nd, 2022

Patents/IP/Tech Transfer/Licensing

Study finds nanomedicine targeting lymph nodes key to triple negative breast cancer treatment: In mice, nanomedicine can remodel the immune microenvironment in lymph node and tumor tissue for long-term remission and lung tumor elimination in this form of metastasized breast cance May 13th, 2022

Metasurfaces control polarized light at will: New research unlocks the hidden potential of metasurfaces August 13th, 2021

Arrowhead Pharmaceuticals Announces Closing of Agreement with Takeda November 27th, 2020

HORIBA Medical and CEA-Leti Strengthen Their Partnership to Develop Tomorrow’s Diagnostics at the Point of Care July 21st, 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