Materials

"Rebar graphene" foam supports 3,000 times its own weight

"Rebar graphene" foam supports...
Material scientists from Rice University have reinforced graphene with carbon nanotubes, creating 3D structures that can support 3,000 times their own weight
Material scientists from Rice University have reinforced graphene with carbon nanotubes, creating 3D structures that can support 3,000 times their own weight
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The structure of the carbon nanotube-reinforced 3D graphene shapes
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The structure of the carbon nanotube-reinforced 3D graphene shapes
In this microscope image, graphene is marked in blue, and the carbon nanotubes in orange
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In this microscope image, graphene is marked in blue, and the carbon nanotubes in orange
Under a microscope, the carbon nanotubes and carbon shells can be seen in a 2D sheet of graphene
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Under a microscope, the carbon nanotubes and carbon shells can be seen in a 2D sheet of graphene
Material scientists from Rice University have reinforced graphene with carbon nanotubes, creating 3D structures that can support 3,000 times their own weight
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Material scientists from Rice University have reinforced graphene with carbon nanotubes, creating 3D structures that can support 3,000 times their own weight

Graphene spends most of its time in a two-dimensional form, but that makes it hard to make use of its long list of advantages, like its strength, light weight, and electricity and heat conduction. MIT scientists recently developed a 3D version that's 10 times stronger than steel but a fraction of the density, and now a team at Rice University has used carbon nanotubes to reinforce graphene foam. The resulting 3D material can be molded into any shape and supports 3,000 times its own weight before springing back to its original height.

Named for the rebars (reinforcing bars) commonly used to strengthen concrete, Rice's "rebar graphene" is built around carbon nanotubes with several concentric layers. In previous work the team had created three-dimensional graphene foam, and having already used the nanotubes to reinforce regular old 2D graphene, it made sense to combine the two.

"We developed graphene foam, but it wasn't tough enough for the kind of applications we had in mind, so using carbon nanotubes to reinforce it was a natural next step," says James Tour, lead researcher on the study.

The team mixed the nanotubes in with a powdered nickel catalyst and sugar to provide the carbon. Dried pellets of the substance were then pressed in a steel die in the shape of a screw, and the carbon in the sugar was turned into graphene through the process of chemical vapor deposition. Any remaining traces of nickel were removed, and the final result was a pure carbon, screw-shaped piece of graphene foam.

The structure of the carbon nanotube-reinforced 3D graphene shapes
The structure of the carbon nanotube-reinforced 3D graphene shapes

When viewed under an electron microscope, the researchers could see that the outer layers of the nanotubes had started to "unzip" and bonded with the graphene, which allowed the material to hold over 3,000 times its own weight without permanent damage. Even with a burden of 8,500 times its weight, the structure deformed permanently by only 25 percent. By comparison, graphene foam with no supporting nanotube structure began to struggle under a load of just 150 times its own weight.

While graphene foam can be formed into basically any shape, the researchers demonstrated that their creation worked as an electrode in a lithium-ion capacitor, and stayed mechanically and chemically stable.

The research was published in the journal ACS Applied Materials and Interfaces.

Source: Rice University

6 comments
TomBateman
Is it also possible to replace ferrous re-bar in preformed concrete slabs? Less corrosion in concrete situ over time with Graphene versus ferrous re-bar; lighter to transport; less fixing
Bob Stuart
Could we please have some useful numbers? If a block of foam is 3" thick, the bottom .001" is supporting 3,000 times its own weight. The three properties of matter are strength, stiffness, and toughness, and these are NOT synonyms.
Buellrider
Could it be used for a spinal disc replacement?
Future3000
@ Bob Stuart: Tank you! It sounds sooooo good "3.000 times of own weight". An standard M 6 x 20 mm screw weights 5,8 grams. We all know it can carry MORE than 17,4 Kilograms... in BOTH directions. So WHAT did this article of Rice University wants to say us? They try to make plane Graphene layers into 3 D forms. If they had understand the nature of Graphene, they would know, you can create 3 D hexagonal "Graphene" via plasmaspraying carbon... Oh no, that's not american, so we can't do it... but please give us a lot of taxpayers money so we can try it to make it American! BTW: If you take a steelplate 10 x 10 x 1 cm. weight 700 grams, it can carry up to 700 tons... it's 1 million times it's own weight. No Graphene needed.
JimFox
Very nice BUT in 35 years of rebar design I have seen bar joiners used only in a few extreme circumstances; bar laps are cheaper, quicker & more reliable.
jimbo92107
Seems analogous to polymer chemistry. Longer chain nanotube adjusts between tougher and more flexible, like that.