Game-changing graphene: the amazing properties of a single-atom layer of carbon

By Catherine

Written by Catherine Bolgar

 

Step aside, silicon. There’s a new substance that promises to revolutionize medicine, industry, water treatment, electronics and much more. That substance is graphene—a single-atom-thick layer of carbon, a millionth of the width of a human hair.

 

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The world’s first two-dimensional material, graphene is potentially plentiful (carbon being the sixth most abundant element in the universe) and cheap. And it possesses amazing qualities and potential uses:

It’s transparent, but conducts…

electricity and heat. Most good conductors are metals such as copper, which is opaque and quick to heat when electricity passes through. But they are prone to hot spots, which form around defects and cause electronic devices to fail. Graphene, by contrast, transfers heat efficiently. “It’s a good alternative to copper,” says Nai-Chang Yeh, professor of physics at California Institute of Technology. Indeed, electronic equipment may in future use graphene-coated copper interconnections to prevent overheating or wear and tear.

It’s light and flexible, but it is…

Hands of scientific showing a piece of graphene with hexagonal molecule.200 time stronger than steel. The carbon-to-carbon bond is very strong, says Rahul Nair, Royal Society fellow at the University of Manchester. In addition, graphene’s carbon atoms are arranged in a tight, uniform honeycomb structure, which is able to bear loads and resist tearing. A membrane of graphene could withstand strong force without breaking, says Dr. Yeh. It may someday be used in aerospace, transportation, construction and defense.

It’s a superlubricant

“If you take one piece of flawless graphene and put it on top of another, and slide one against the other, there’s almost no friction,” says Dr. Yeh. Coating machines parts with graphene could minimize unwanted friction, providing industry with countless applications.

It’s impermeable…

Graphene’s honeycomb structure is too tight for any molecules to squeeze through. “If you have graphene on metal, it’s perfect protection, because other molecules in the air cannot penetrate that honeycomb hole,” says Dr. Yeh. Indeed, Dr. Nair has dissolved graphene oxide in water to create a paint-like film that can protect any surface from corrosion. This graphene paint could be used by the oil and gas industry to protect equipment against saltwater, or by pharmaceutical and food packaging firms to block out oxygen and moisture, thereby extending their products’ shelf life, says Dr. Nair.

…but can also be permeable. A single-micrometer-thick film containing thousands of layers of graphene oxide has nanosize capillaries between its layers, which expand when exposed to water. However, those capillaries don’t expand when exposed to other substances. This is unusual because a water molecule is bigger than a helium or hydrogen molecule. However, water behaves differently when it’s within the confined space of a nanometer, moving rapidly through the graphene oxide nanocapillary. By contrast, salt that is dissolved in the water is blocked. One use for this, says Dr. Nair, could be water or molecular filtration.

It’s a chemical contradiction

A sheet of graphene is inert, but its edges are chemically reactive, says Dr. Yeh. A little graphene flake has a large perimeter relative to its area, allowing for more reaction. These flakes could be used to remove toxins from water.

It can be magnetic

MagnetThe zigzag-shaped edges of graphene have magnetic properties.“People imagine that you will be able to use graphene sheets as a magnet that can pick up iron at room temperature,” explains Dr. Yeh. That something all-carbon can be magnetic is “amazing,” she adds. Coupled with its electric conductivity, graphene’s magnetic properties may open up all sorts of applications in spintronics and semiconductors.

Graphene’s potential may be extraordinary, but how easy is it to create? It was first isolated in 2004 at Manchester University by Andre Geim and Konstantin Novoselov who won the 2010 physics Nobel Prize for their work. They arrived at graphene by using adhesive tape to peel off ever-thinner layers from graphite, a process subject to continual improvement. In one common method, copper is heated to 1,000 degrees Celsius, near its melting point. Methane gas, comprising carbon and hydrogen molecules, is then added, and the copper rips off the bond between the two molecules, dissolving the carbon into the copper and letting the carbon “grow” on the surface, Dr. Yeh explains. The result is a sheet of graphene.

David Boyd and Wei-Hsiang Lin, working with Dr. Yeh at Caltech, however, found that what counts most is not heat but clean copper.  Copper oxidizes quickly in air and so has a thin layer of carbon oxide on its surface. They use hydrogen plasma, which has “gas radicals that behave like erasers and clean up the surface of the copper,” Dr. Yeh explains. The process allows graphene to grow in five minutes at room temperature.

Most importantly, this method could be scaled up to produce industrial amounts of high-quality graphene—a huge step towards realizing its true potential.

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. 

For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.

 

Photos courtesy of iStock

Spotlight on buildingSMART: Driving an open approach to design and construction evolution

By Akio

When Richard Petrie joined buildingSMART as chief executive officer in 2013, he took on the goal of driving the standards-writing organization’s growth — in order to drive change across the entire architecture, engineering and construction industry.

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Richard Petrie, CEO of buildingSMART

Having worked in construction as both contractor and client, Petrie has seen firsthand the frustrations of a slow-to-evolve architecture, engineering and construction industry. From within buildingSMART — a not-for-profit organization that has been working to standardize the language and processes of BIM (Building Information Modeling) users since 1995 — Petrie has observed an increasing emphasis from several European governments on improving construction efficiency.

“All of those governments have very serious social needs that they have to fulfill with increasingly limited budgets,” Petrie says. “Completing these projects in the best way possible is very important, and you can’t do that if you don’t have accurate and clear data.”

buildingSMART is setting out to provide that data by leading the entire building industry into the digital economy.

Overcoming Fragmentation

There are two key challenges in architecture, engineering and construction industry that buildingSMART is seeking to address.

First is the fragmentation of the supply chain.12 As designers, builders and owners expand their focus to the entire life cycle, it becomes increasingly important to understand how each component and system impacts others. While savvy suppliers are integrating vertically, providing inter-related products, services and knowledge, many designers are finding the information they need through sharable information made possible by BIM.

Second, Petrie finds, construction clients are rarely well informed about the construction, building management and asset ownership process, which means they are also fragmented. For example, the efficiency to which buildings are designed isn’t always met in operation. This is in part because product data isn’t easily transferred from designers and builders to owners and facility managers.

“Altogether, this disjointed relationship with clients and the fragmentation of the supply chain is a great drag on the transformation of the industry,” Petrie says.

Tweet: The #AEC industry is plagued w/ fragmentation & miscommunication. @openbim & @buildingSMART offer a solution. @3DSAEC http://ctt.ec/dP4ea+Click to tweet: “The #AEC industry is plagued w/ fragmentation &
miscommunication. @openbim & @buildingSMART offer a solution.”

 Creating a Universal Approach to Construction

buildingSMART describes openBIM as a “universal approach” to the collaborative design, realization and operation of buildings based on open standards, such as its IFC family of standards. This approach allows all project members to participate in modeling, regardless of the software tools they use; it creates a common language for widely referenced processes; and it provides one system for housing asset data over its entire life-cycle.

Petrie sees openBIM as a solution to the industry’s fragmentation challenges and buildingSMART as a path to the significant opportunities for improvement in building and infrastructure cost, value and environmental performance.

“I believe those opportunities are only truly available with open international standards and, in order to create those open international standards, a neutral entity for the development and promulgation of those standards is needed,” Petrie explains. “That is the role buildingSMART International is taking on.”

With its newly defined vision, the volunteer-driven organization has made major headway in the past year. From creating new standards to defining data to the harmonization of processes across the supply chain, the group has demonstrated real progress and results.

The Push for Interoperability

The group’s push for progress aligns with demand from several governments. As a case in point: Petrie indicates the UK government’s push for interoperability as an example of where openBIM is heading.

While the UK has had requirements for open data since 2012, in 2016 the government will formally launch a program in which procurements must use BIM Level 2 documents.

This set of methodologies is designed to introduce the construction supply chain to trading and operating in a data environment, allowing the government to focus on the strongest leaders and drive value for its spending programs.

It’s a demand driven not by technology, Petrie says, but a cultural shift resulting from seeing real change in how each construction dollar is spent. “That is the reality that will provide the real driver to ensure that this program moves forward the way we hope it will,” he says.

Petrie adds that thus far the group is achieving its predicted targets in the UK, and work is underway for a Level 3 program slated for 2020-2025.

Tweet: Demand for #BIM L2 is a result of seeing change in how each construction dollar is spent @buildingSMART @3DSAEC #AEC http://ctt.ec/o1bHe+Click to tweet: “Demand for #BIM L2 is a result of
seeing change in how each construction dollar is spent”

The Smart Future of Building

To expand the organization’s work, Petrie is seeking to build a community of experts to ensure that future standards accurately reflect the needs of real-world users. Volunteers work at both the international and chapter level, in an integrated process for developing new standards and deploying them into user communities.

buildingSMART graphic_03.2015

Membership in buildingSMART International is open to companies, government bodies and institutions from around the world. Dassault Systèmes joins buildingSMART as an International Member, with full voting membership rights on the new Standards Committee and membership rights with buildingSMART chapters.

The company joins other leading proponents of openBIM that recognize the benefits from openBIM can achieve the greatest impact and momentum by working together in a common community.

Members benefit from the collective activities of other members locally and internationally, and play an active role not only in identifying issues, but also in the development of solutions.

The nature of buildingSMART is that it is a voluntary organization where solutions are developed on a mutually supportive co-developed basis, and so we need members to be active in our community,” Petrie explains.

Petrie acknowledges that it will take time to develop and communicate the organization’s mission, but, he adds, “The changes that we are hoping will be available as a result of these new standards will not only affect the technical communities, but will have implications for the way in which companies function.

Tweet: Spotlight on @buildingSMART: Driving an open approach to design and #construction evolution @3DSAEC @Dassault3DS #AEC http://ctt.ec/dfNk2+Click to tweet this article.

 

Related Resources:

Dassault Systemes Architecture, Engineering and Construction Solutions

buildingSMART website

White Paper: End-To-End Collaboration Enabled by BIM Level 3

Stronger, Lighter, Cheaper

By Catherine

Written by Catherine Bolgar*
NanomaterialIndustrial materials involve trade-offs. Desirable qualities tend to come with undesirable flip sides. Strength, for example, tends to come at the expense of ductility, or the ability to stretch without breaking. So the stronger something is, the more it’s likely—ironically—that when it does fail, it fails completely.

What if you could have both high strength and ductility? This is likely to happen, thanks to breakthroughs in new materials, many of which involve building the materials in innovative ways at the atomic level.

A microscopic view of metals would show them as made up of grains. Stronger materials have smaller grains, and more ductile materials have larger grains, explains Yuntian Zhu, professor of materials science and engineering at North Carolina State University in the U.S. However, if you make an entire part with small grains for high strength, it might fail catastrophically under stress.

When you make any structure, you want at least 5% ductility. The more ductility, the safer it is. But the downside is that the strength comes down,” he says.

Dr. Zhu found that by forming steel with larger grains inside and gradually moving to smaller grains at the surface, the result has both strength and ductility. This gradient structure is found in nature, he says, for example in plants and bones.

Near the surface, it’s harder. As you go deeper it gets softer,” Dr. Zhu says. “Nature just puts raw materials where they’re needed most. It minimizes the material cost. In nature, that proves useful.”

Using a gradient structure in steel could extend the lives of bridges, ships and oil pipelines, for instance.

Hardening steel by working it is another technique to make steel that’s both strong and ductile. Twinning-induced plasticity—or TWIP—steel is strengthened by twisting, deforming, bending, flattening or hammering it. At Brown University, researchers twisted cylinders of TWIP steel to deform the molecules on the surface. The molecules in the center remained unaffected, providing the flexibility, while the surface got harder, providing more strength.

Usually when something is strong, it’s also heavy. What if you could have both strength and lightness?

Nicholas X. Fang, associate professor of mechanical engineering at the Massachusetts Institute of Technology, has developed a foam material that can withstand a weight 10,000 times greater than its own.

“It’s as light as aerogel, yet as stiff as a hammer,” he says. Much of the space between the structures is void, which is why the material is so light.

The material uses nanotubes or nanowires a quarter of the size of a human hair to form a network or structure that takes away the load. “Each of the nanotubes under the load are under compression or a stress state,” Dr. Fang says. “But they turn out to be quite resilient. In the lab, we compress the samples to 60% of their original size.”

Dr. Fang is contemplating applications for this new material. The material could absorb impact while reducing weight, for example, in a tennis racket that’s lighter than aluminum alloy, yet able to deliver similar strength against a bouncing ball.

It could be important for microstructures in batteries,” he adds. Batteries receive a lot of shock when charging, which causes the structure to suddenly expand—and corrode. “If we could use this material in a battery, we could solve the challenge of quick charging,” he says.

Satellites also could benefit from a material that’s very lightweight, to reduce the payload, yet able to withstand shocks.

Nanowires in three-dimensional structures also are being explored by researchers at the University of California, Davis. By combining atoms of semiconductor materials—such as gallium arsenide, gallium nitride or indium phosphide—into nanowires that form structures on top of silicon surfaces, they hope to create a new generation of fast electronic and photonic devices.

The nanowire transistors could be used to make sensors that can withstand high temperatures and are easier to cool.

polymer surfaceSomething everybody wants to be strong yet shatterproof is their smartphone screen. Researchers at the University of Akron in Ohio have come up with a transparent layer of electrodes on a polymer surface that could stand up to repeatedly having adhesive tape peeled off and retain its shape after being bent a thousand times. The new film may be cheaper to make than the coatings of indium tin oxide now used on smartphone screens.

In fact, in a number of cases, the materials or processes themselves aren’t necessarily expensive, which makes them likely to be adopted relatively quickly.

It’s actually quite easy,” says Dr. Zhu about making steel with a gradient structure. “The only thing is, can we do it in an industrial way or develop a technology to do it?” The cost is likely to be very low, and some in industry already are trying it.

“It might take a few years for widespread adoption,” he says.

The super-strong foam material developed by Dr. Fang isn’t expensive, but the manufacturing process is—at least for now. Only a few centimeters of the material can be made, which is a limitation of the printing process, not the material itself, Dr. Fang says. “Now it’s important to connect the dots to make it into a larger format at lower cost.”

*For more from Catherine, contributors from the Economist Intelligence Unit along with industry experts, join The Future Realities discussion.



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