GrapheneScientists have turned wood into an electrical conductor by making its surface graphene.

Chemist James Tour of Rice University and his colleagues used a laser to blacken a thin film pattern onto a block of pine. The pattern is laser-induced graphene (LIG), a form of the atom-thin carbon material discovered at Rice in 2014.

“It’s a union of the archaic with the newest nanomaterial into a single composite structure,” Tour says.

Previous iterations of LIG were made by heating the surface of a sheet of polyimide, an inexpensive plastic, with a laser. Rather than a flat sheet of hexagonal carbon atoms, LIG is a foam of graphene sheets with one edge attached to the underlying surface and chemically active edges exposed to the air.

Not just any polyimide would produce LIG, and some woods work better than others, Tour says. The research team tried birch and oak, but found that pine’s cross-linked lignocellulose structure made it better for the production of high-quality graphene than woods with a lower lignin content. Lignin is the complex organic polymer that forms rigid cell walls in wood.

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By: Sameer Sonkusale, Tufts University

Nanowires

Image: Alonso Nichols, Tufts University, CC BY-ND

Doctors have various ways to assess your health. For example, they measure your heart rate and blood pressure to indirectly assess your heart function, or straightforwardly test a blood sample for iron content to diagnose anemia. But there are plenty of situations in which that sort of monitoring just isn’t possible.

To test the health of muscle and bone in contact with a hip replacement, for example, requires a complicated – and expensive – procedure. And if problems are found, it’s often too late to truly fix them. The same is true when dealing with deep wounds or internal incisions from surgery.

In my engineering lab at Tufts University, we asked ourselves whether we could make sensors that could be seamlessly embedded in body tissue or organs – and yet could communicate to monitors outside the body in real time. The first concern, of course, would be to make sure that the materials wouldn’t cause infection or an immune response from the body. The sensors would also need to match the mechanical properties of the body part they would be embedded in: soft for organs and stretchable for muscle. And, ideally, they would be relatively inexpensive to make in large quantities.

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MXene

MXene is a nanomaterial that can super effectively block and absorb electromagnetic radiation.
Image: Drexel University

We’ve all experienced electromagnetic interference, whether it’s hearing your car engine break in your AM radio station or the squealing of speakers at a concert when a cellphone gets to close. However, researchers from Drexel University may have found a way to all but stop this interference though what they’re calling MXene (2D Transition Metal Carbides).

Electromagnetic interference isn’t just annoying for users, it’s damaging for devices and could lead to the overall degradation of cellphones, laptops, and other electronics.

Typically, to block this interference, scientists encase the interior of electronics with conductive metal (i.e. metal, copper, or aluminum). But researchers for this new study found that a few-atoms thin titanium carbide may be more effective at blocking such interference. Additionally, it is extremely easy to apply – with the ability to be sprayed on to any surface just like paint.

“With technology advancing so fast, we expect smart devices to have more capabilities and become smaller every day. This means packing more electronic parts in one device and more devices surrounding us,” says ECS Fellow Yury Gogotsi, lead author of the research. “To have all these electronic components working without interfering with each other, we need shields that are thin, light and easy to apply to devices of different shapes and sizes. We believe MXenes are going to be the next generation of shielding materials for portable, flexible and wearable electronics.”

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A new report by TechXplore examines a recently published review paper on the potential in nanomaterials for rechargeable lithium batteries. In the paper, lead-author and ECS member Yi Cui of Stanford University, explores the barriers that still exist in lithium rechargeables and how nanomaterials may be able to lend themselves to the development of high-capacity batteries.

When trying to design affordable batteries with high-energy densities, researchers have encountered many issues, including electrode degradation and solid-electrolyte interphase. According to the paper’s authors, possible solutions for many of these hurdles lie in nanomaterials.

Cui’s comprehensive overview of rechargeable lithium batteries and the potential of nanaomaterials in these applications came from 100 highly-reputable publications, including the following ECS published papers:

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Inorganic Chemist Named MacArthur Genius

The 2015 MacArthur Foundation geniuses have just been revealed, with seven prolific scientists receiving the prestigious title. Of those scientists, inorganic chemist Peidong Yang was named as one of this year’s geniuses for his pioneering work in nanomaterials science. His work is not only transformative for the science of semiconductor nanowires and nanowire photonics, it is also opening new paths for clean, renewable energy.


His research has led to innovative commercial productions for the conversion of waste heat to electricity, chemical sensors, and optical switches. Currently, Yang’s focus is directed toward artificial photosynthesis, where he and his research group have created a synthetic “leaf” that is a hybrid system of semiconducting nanowires and bacteria.

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nanomaterialMore and more people are looking toward nanomaterials to help solve issues in the energy infrastructure. Not only could this technology lead to more efficient and cost effective renewable energy sources, but could also help the development of devices that remove pollutants from the air and water. In fact, nanotechnology has such a vast scope that there is potential for it to impact almost all areas of society.

“There is not a field that is not touched,” said nanomaterials expert Francis D’Souza of the University of North Texas. “It is a group of very eminent scientists exploring the possibilities in every single field. You can expect big discoveries and breakthroughs.”

While nanomaterials are infiltrating everything from electronics to biomedical applications, many scientists have shift their primary focus to energy harvesting.

“There are so many new capabilities that can be exploited with nanotechnology, from dramatic improvements to solar conversion efficiency to battery systems with higher storage capacity and faster charging and discharging cycles to miniaturized power management systems, so we can have energy storage that can last for a long time,” said IBM’s Lili Deligianni.

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Deep-Fried Graphene for Energy Storage

The 5-µm-diameter graphene balls in these scanning electron microscope images contain graphene nanosheets radiating outward from the center.Credit: Chem. Mater.

The 5-µm-diameter graphene balls in these scanning electron microscope images contain graphene nanosheets radiating outward from the center.
Credit: Chem. Mater.

Materials scientists have developed a new technique that could provide a simpler and more effective way to produce electrode materials for batteries and supercapacitors, which could potentially lead to devices with improved energy and power densities.

The researchers have unlocked this new battery technology by exposing tiny bits of graphene to a process that is very similar to deep-frying.

Prior to this development, scientists had difficulty using graphene in electrodes due to the difficulty encountered when processing the material. However, the researchers out of Yonsei University have learned how to harness the material’s electrical and mechanical properties while retaining its high surface are by using an alternative technique.

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Member Spotlight – Jiaxing Huang

ECS member Jiaxing Huang used freshman-level chemistry to solve the solubility mystery of graphene oxide films.Image: Northwestern University

ECS member Jiaxing Huang used freshman-level chemistry to solve the solubility mystery of graphene oxide films.
Image: Northwestern University

Sometimes science can be extremely complex and commanded by technical expertise. But there are moments when one has to go back to his roots to find a more simple answer for a complex issue. That is what ECS member Jiaxing Huang – along with a team of Northwestern University researchers – has done in order to solve the mystery that surrounds the solubility of graphene oxide films.

For years, one question has puzzled the materials science community – why are graphene oxide (GO) films highly stable in water?

When submerged, GO sheets become negatively charged and repel, which should cause membrane to disintegrate. Though much to the confusion of the scientific community, when GO sheets are submerged they stabilize.

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