Material Science News and Discussions

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LionGlass boasts 10x the strength of regular glass, greener production
By Michael Irving
July 03, 2023
https://newatlas.com/materials/lionglas ... s-greener/

Despite its many advantages, glass has one major Achilles' heel – it’s brittle. Now, engineers at Penn State have developed LionGlass, a new type of the material that’s not only 10 times more damage resistant, but requires significantly less energy to manufacture.

The most commonly used form of glass, which you’ll find in everything from windows to drinking glasses, is technically known as soda lime silicate glass. Manufacturing this common material requires furnaces that get up to 1,500 °C (2,732 °F), which of course consumes a lot of energy and releases a huge amount of carbon dioxide into the atmosphere. On top of that, this glass is made from quartz sand, soda ash and limestone, the latter two of which release CO2 when melted.

Now, Penn State researchers have improved the recipe to make glass that’s more environmentally friendly to produce, while also being much stronger. The family of new glass compositions, which the team calls LionGlass, get their new powers by swapping the soda ash and limestone for either aluminium oxide or an iron compound. The silica content can vary from 40% to 90% by weight.

Better yet, some compositions of LionGlass were found to boast crack resistance that was at least 10 times higher than that of standard soda lime glass. The team tested samples under a Vickers diamond indenter, and found that the glass didn’t crack even under a force-load of 1 kg (2.2 lb) – by comparison, regular glass will start to crack under a load of just 0.1 kg (0.2 lb). And LionGlass’s crack resistance is likely even higher than that, but this was as high as the testing equipment could go.

“We kept increasing the weight on LionGlass until we reached the maximum load the equipment will allow,” said Nick Clark, a researcher on the project. “It simply wouldn’t crack.”

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Researchers reveal a powerful platform for studying high-entropy alloy electrocatalysis
https://phys.org/news/2023-07-reveal-po ... alloy.html
by Tohoku University

Introduced in 2004, high-entropy alloys (HEAs) are alloys composed of multiple principal elements in nearly equiatomic proportions. Their unique chemical composition results in a high degree of chemical disorder, i.e., entropy, and produces remarkable properties such as high strength, ductility, and strong wear-and-tear resistance even at high temperatures. Scientists have dedicated a significant amount of attention to developing novel HEAs to help improve the performance of various electrocatalyst materials.

Because they are made up of differing constituent elements, HEAs' atomic-level surface designs can be complex. But unraveling this complexity is crucial, since the surface properties of materials often dictate their catalytic activity. This is why researchers are seeking to understand the correlation between the atomic arrangement and the catalytic properties exhibited by HEAs.

Now, a collaborative research team has created a new experimental platform that enables the control of the atomic-level structure of HEAs' surfaces and the ability to test their catalytic properties. Their breakthrough was reported in the journal Nature Communications on July 26, 2023.

"In our study we made thin layers of an alloy called a Cantor alloy, which contains a mix of elements (Cr-Mn-Fe-Co-Ni), on platinum (Pt) substrates," explains Toshimasa Wadayama, co-author of the paper and a professor at Tohoku University's Graduate School of Environmental Studies. "This produced a model surface for studying a specific reaction called the oxygen reduction reaction (ORR).

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Putting starch into bio-based polymer makes bioplastics more compostable
https://phys.org/news/2023-08-starch-bi ... table.html
by Matt Davenport, Michigan State University

Researchers from Michigan State University's top-ranked School of Packaging have developed a way to make a promising, sustainable alternative to petroleum-based plastics more biodegradable.

A team led by Rafael Auras has made a bio-based polymer blend that's compostable in both home and industrial settings. The work is published in the journal ACS Sustainable Chemistry & Engineering.

"In the U.S. and globally, there is a large issue with waste and especially plastic waste," said Auras, MSU professor and the Amcor Endowed Chair in Packaging Sustainability.

Less than 10% of plastic waste is recycled in the U.S. That means the bulk of plastic waste ends up as trash or litter, creating economic, environmental and even health concerns.

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Breakthrough polymer research promises to revolutionize recycling
https://phys.org/news/2023-08-breakthro ... cling.html
by Brian Smith, University of Florida

A team of researchers led by Brent Sumerlin, the George B. Butler Professor in the University of Florida Department of Chemistry, has made a breakthrough with the potential to transform how we recycle plastics. Their innovative approach to working with polymers has led them to develop a new method for recycling that promises to lower the energy requirement without sacrificing the quality of the plastic.

It's no secret that the U.S. and the Earth at large have a pressing plastic problem. Despite a meteoric rise in usage over the past few decades, only about 10% of our plastic currently ends up getting recycled.

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Researchers develop method for upcycling plastic waste into soap
https://phys.org/news/2023-08-method-up ... -soap.html
by Virginia Tech

A team led by Virginia Tech researchers has developed a new method for upcycling plastics into high-value chemicals known as surfactants, which are used to create soap, detergent, and more. The work was published in Science.

Plastics and soaps tend to have little in common when it comes to texture, appearance, and, most importantly, how they are used. But there is a surprising connection between the two on a molecular level: The chemical structure of polyethylene—one of the most commonly used plastics in the world today—is strikingly similar to that of a fatty acid, which is used as a chemical precursor to soap. Both materials are made of long carbon chains, but fatty acids have an extra group of atoms at the end of the chain.

Guoliang "Greg" Liu, associate professor of chemistry in the Virginia Tech College of Science, had long felt this similarity implied that it should be possible to convert polyethylene into fatty acids—and with a few additional steps to the process—to produce soap. The challenge was how to break a long polyethylene chain into many short—but not too short—chains and how to do it efficiently. Liu believed there was the potential for a new upcycling method that could take low-value plastic waste and turn it into a high-value, useful commodity.

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Chemists develop unique design for tough but stretchable gels
https://phys.org/news/2023-08-chemists- ... -gels.html
by Washington University in St. Louis

Chenfeng Ke, an incoming associate professor of chemistry in Arts & Sciences at Washington University in St. Louis, developed a unique design for tough but stretchable hydrogels, reported Aug. 23 in the journal Chem. The new material is both flexible and durable thanks to a ring-shaped sugar molecule that encases its polymer network and allows it to stretch without sacrificing strength.

Ke can 3D-print the so-called crystalline-domain reinforced slide-ring hydrogels, or CrysDoS-gels. He and his co-authors also created a materials library and offer methods for how the material can be added to existing materials to enhance their durability, such as in plastic additives to enhance the durability for parts in automobiles in the future.

"There are a series of tradeoffs with these traditional plastic materials—they're usually one or the other," stretchable or rigid, Ke said. "But if you connect two things with a slidable joint, you have very interesting properties of both."

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Developing novel conducting polymer-hydrogel interpenetrating networks for neural interfacing
https://phys.org/news/2023-09-polymer-h ... acing.html
by Li Yuan, Chinese Academy of Sciences

A research group led by Prof. Lu Yi from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences (CAS) has proposed three-dimensional (3D) conductive polymer-hydrogel interpenetrating networks for high-performance chronic electrode/neural interfacing. The study was published in ACS Applied Materials & Interfaces.

Long-term, reliable detection of electrophysiological signals is pivotal for comprehending mechanisms that underlie brain disorders and for advancing effective treatments. Nonetheless, maintaining stability and biocompatibility of neural electrode interface for necessary extended periods remains challenging.

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Striking rare gold: Researchers unveil new material infused with gold in an exotic chemical state

September 30, 2023

For the first time, Stanford researchers have found a way to create and stabilize an extremely rare form of gold that has lost two negatively charged electrons, denoted Au2+. The material stabilizing this elusive version of the valued element is a halide perovskite—a class of crystalline materials that holds great promise for various applications including more-efficient solar cells, light sources, and electronics components.

Surprisingly, the Au2+ perovskite is also quick and simple to make using off-the-shelf ingredients at room temperature.

https://phys.org/news/2023-09-rare-gold ... fused.html



Credit: Karunadasa et al. 2023.

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C-Crete hailed as a planet-friendly alternative to cement
By Ben Coxworth
October 13, 2023
https://newatlas.com/environment/c-cret ... ternative/

According to some estimates, the generation of the heat used to produce traditional portland cement is responsible for 5% to 8% of all human-made CO2 emissions. A new substance known as C-Crete, however, is claimed to be a much greener – yet still practical – alternative.

C-Crete is being developed by a California-based startup of the same name, which was founded by MIT Civil and Environmental Engineering grad Rouzbeh Savary.

Although the product's exact ingredients are a closely guarded trade secret for now, it is said to contain "patent-pending materials" that bind with unspecified mineral feedstocks and industrial byproducts which clients can obtain locally. Importantly, no heat is required in its production.

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New class of recyclable polymer materials could one day help reduce single-use plastic waste
https://phys.org/news/2023-10-class-rec ... s-day.html
by Katherine Harry and Emma Rettner, The Conversation

Hundreds of millions of tons of single-use plastic ends up in landfills every year, and even the small percentage of plastic that gets recycled can't last forever. But our group of materials scientists has developed a new method for creating and deconstructing polymers that could lead to more easily recycled plastics—ones that don't require you to carefully sort out all your recycling on trash day.

In the century since their conception, people have come to understand the enormous impacts—beneficial as well as detrimental—plastics have on human lives and the environment. As a group of polymer scientists dedicated to inventing sustainable solutions for real-world problems, we set out to tackle this issue by rethinking the way polymers are designed and making plastics with recyclability built right in.
Why use plastics, anyway?

Everyday items including milk jugs, grocery bags, takeout containers and even ropes are made from a class of polymers called polyolefins. Polyolefins make up around half of the plastics produced and disposed of every year.

These polymers are used in plastics commonly labeled as HDPE, LLDPE or PP, or by their recycling codes #2, #4 and #5, respectively. These plastics are incredibly durable because the chemical bonds that make them up are extremely stable. But in a world set up for single-use consumption, this is no longer a design feature but rather a design flaw.

Imagine if half of the plastics used today were recyclable by twice as many processes as they are now. While that wouldn't get the recycling rate to 100%, a jump from single digits—currently around 9%—to double digits would make a big dent in the plastics produced, the plastics accumulated in the environment and their capacity for recycling and reuse.