New form of carbon that's hard as a rock, yet elastic, like rubber

June 9, 2017
Visualization of the different types of diamond-like linkages (red spheres) formed at curved surfaces or between the layers of graphene (black spheres) in this new type of compressed glassy carbon. Credit: Timothy Strobel.

A team including several Carnegie scientists has developed a form of ultrastrong, lightweight carbon that is also elastic and electrically conductive. A material with such a unique combination of properties could serve a wide variety of applications from aerospace engineering to military armor.

Carbon is an element of seemingly infinite possibilities. This is because the configuration of its electrons allows for numerous self-bonding combinations that give rise to a range of with varying properties. For example, transparent, superhard diamonds, and opaque graphite, which is used for both pencils and industrial lubricant, are comprised solely of carbon.

In this international collaboration between Yanshan University and Carnegie—which included Carnegie's Zhisheng Zhao, Timothy Strobel, Yoshio Kono, Jinfu Shu, Ho-kwang "Dave" Mao, Yingwei Fei, and Guoyin Shen—scientists pressurized and heated a structurally disordered form of carbon called glassy carbon. The glassy carbon starting material was brought to about 250,000 times normal atmospheric pressure and heated to approximately 1,800 degrees Fahrenheit to create the new strong and elastic carbon. Their findings are published by Science Advances.

Scientists had previously tried subjecting glassy carbon to high pressures at both room temperature (referred to as cold compression) and extremely high temperatures. But the so-called cold-synthesized material could not maintain its structure when brought back to ambient pressure, and under the extremely hot conditions, nanocrystalline diamonds were formed.

Visualization of ultrastrong, hard and elastic compressed glassy carbon. The illustrated structure is overlaid on an electron microscope image of the material. Credit: Timothy Strobel.

The newly created carbon is comprised of both graphite-like and diamond-like bonding motifs, which gives rise to the unique combination of properties. Under the high-pressure synthesis conditions, disordered layers within the glassy carbon buckle, merge, and connect in various ways. This process creates an overall structure that lacks a long-range spatial order, but has a short-range spatial organization on the nanometer scale.

The video will load shortly
Compressed glassy carbon is an ultrastrong, hard and elastic type of carbon that consists of interpenetrating graphene networks. This video summary shows an example indentation hardness test, scratch hardness test, and provides a description of the specific strength and local atomic structure. Credit: Zhisheng Zhao and Timothy Strobel

"Light materials with high strength and robust elasticity like this are very desirable for applications where weight savings are of the utmost importance, even more than material cost," explained Zhisheng Zhao a former Carnegie fellow, who is now a Yanshan University professor. "What's more, we believe that this synthesis method could be honed to create other extraordinary forms of and entirely different classes of materials."

View through the channels of a mixed sp2 / sp3, interpenetrating graphene network in compressed glassy carbon. Graphene‐like sheets (blue spheres) are crosslinked at diamond‐like nodes (red spheres). Credit: Timothy Strobel

Explore further: New extremely hard carbon nitride compound created

More information: "Compressed glassy carbon: An ultrastrong and elastic interpenetrating graphene network," Science Advances (2017). advances.sciencemag.org/content/3/6/e1603213

Related Stories

New extremely hard carbon nitride compound created

October 14, 2016

New work from a team led by Carnegie's Alexander Goncharov has created a new extremely incompressible carbon nitride compound. They say it could be the prototype for a whole new family of superhard materials, due to the unexpected ...

Crystals from chaos: Physicists observe new form of carbon

August 16, 2012

(Phys.org) -- A team of scientists led by Carnegie's Lin Wang has observed a new form of very hard carbon clusters, which are unusual in their mix of crystalline and disordered structure. The material is capable of indenting ...

New form of superhard carbon observed

October 11, 2011

An amorphous diamond – one that lacks the crystalline structure of diamond, but is every bit as hard – has been created by a Stanford-led team of researchers.

Recommended for you

14 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

humy
3.7 / 5 (6) Jun 10, 2017
"...1,800 degrees Fahrenheit ..."

WHY WHY does this report on a scientific finding state temperature in the old obsolete Fahrenheit scale, which is now considered unacceptable in science, rather than in either centigrade or Kelvin, which is the modern accepted standard scales used in science?
Anonym
2.2 / 5 (10) Jun 10, 2017
This article shows why it's misleading to refer to carbon dioxide (CO2) as "carbon," especially in headlines. Carbon is an element, not a compound.

But people think of carbon as synonymous with "coal," which is "sooty," which is why the AGW Malthusian Death Cult consistently associates CO2 with coal. Makes an odorless, colorless, harmless gas seem "dirty." And as the Nazis showed, "dirty" is a very effective demonizer (as in "dirty gypsy") among people with a particularly anal orientation to social engineering.
humy
4.8 / 5 (8) Jun 10, 2017
This article shows why it's misleading to refer to carbon dioxide (CO2) as "carbon,"

What are you talking about? Nowhere in this article does it even mention CO2 and people generally know carbon dioxide is not pure carbon. Extremely few people are so uneducated that they don't know CO2 is normally a gas while pure carbon is normally a solid and thus the two are not the same thing.
But people think of carbon as synonymous with "coal," which is "sooty,"

Which people think this? How do you know such people exist that think this? Can you read minds or do 'they' explicitly say "I believe carbon is coal"...or what exactly? I for one know of no such person.
Captain Stumpy
5 / 5 (1) Jun 10, 2017
WHY WHY does this report on a scientific finding state temperature in the old obsolete Fahrenheit scale, which is now considered unacceptable in science
@Humy
because it's targeting american audiences

the article is written and released for popular news aggregates but still has a target audience (or focus)
I would even suggest the author is US considering the study
When the target pressure was reached, the sample was heated with a rate of 100°C/min to peak temperature, and then was maintained for 2 hours and finally quenched by turning off the electric power supply. The recovered sample rods had both a diameter and height of about 1 to 1.7 mm.

fig. S1. XRD of compressed GCs recovered after compressing raw GC at pressures of 10 to 25 GPa and temperatures of 600° to 1200°C.
PPihkala
5 / 5 (2) Jun 10, 2017
I think they can use Fahrenheit degrees if they want along with Celsius or
Kelvin, but only if either of those is also mentioned.
humy
3 / 5 (2) Jun 11, 2017
WHY WHY does this report on a scientific finding state temperature in the old obsolete Fahrenheit scale, which is now considered unacceptable in science
@Humy
because it's targeting american audiences

cannot American audiences also learn to accept the scientific way? I hope they are not THAT unreasonable..
TheGhostofOtto1923
5 / 5 (1) Jun 11, 2017
cannot American audiences also learn to accept the scientific way?
No.
hope they are not THAT unreasonable..
Sorry to disappoint you. Why don't brits drive on the scientific side of the road?

Re the article how about cheap tires that last forever?
Captain Stumpy
not rated yet Jun 11, 2017
cannot American audiences also learn to accept the scientific way? I hope they are not THAT unreasonable
@humy
the ones so inclined and interested in STEM... they accept the scientific way
the rest?
not so much - it's more about inundation and familiarity at this point

or maybe the belief that we're special in the world? who knows... they tried to introduce metric at one point and it failed miserably except in the STEM courses and military, which is almost exclusively metric now, except in the US where it's using a dual system

.

.

Why don't brits drive on the scientific side of the road?
@otto
their way makes more sense when you're holding a sabre and consider most folk are right handed
cheap tires that last forever?
i was thinking more about space faring craft that can take micrometeorites and travel at higher speeds

TheGhostofOtto1923
5 / 5 (1) Jun 11, 2017
@otto
their way makes more sense when you're holding a sabre and consider most folk are right handed
Only bobbies do this. Because guns are bad.
Shakescene21
not rated yet Jun 12, 2017
This is an intriguing product, but the article does not tell us how this new form of carbon compares with titanium, mylar, etc in hardness, strength, and weight. I hope it is far harder and lighter, but right now it's just an interesting discovery.
krundoloss
3.7 / 5 (3) Jun 12, 2017
Just to chime in, I am totally sick of the "US Customary System" or whatever you want to call it. Every time I go to build something, I start out using Inches and Feet, and just get fed up and start using Centimeters and Millimeters, because it is Vastly Easier. Can we not just let that old measurement system fade away? Its terrible. 5/16", 15/32", WHY GOD WHY
antialias_physorg
5 / 5 (1) Jun 12, 2017
This is an intriguing product, but the article does not tell us how this new form of carbon compares with titanium, mylar, etc

Watch the movie. The relevant graphs are in there.

Totally off topic: I wonder how far off this stuff would be in terms of space elevator material.
Shakescene21
not rated yet Jun 12, 2017
@Antialias. Thanks. As you said, the movie had a chart that answers many of my questions. The numbers are very impressive and they show that this new material has possibilities. The description of the manufacturing process implies that this material could be very expensive, but there are very high-end uses that may beg for it.

(I don't know much about the space elevator, but it seems that it would require huge amounts of this material. Unless the product can be made more cheaply than I expect, it doesn't look likely simply on cost grounds.)
Captain Stumpy
not rated yet Jun 12, 2017
Totally off topic: I wonder how far off this stuff would be in terms of space elevator material.
@Antialias_physorg
... i am just hoping they leave off the Muzak

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.