Material Science News and Discussions

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A thermal management material that responds to heat or cold by folding or unfolding without need for a power source
https://phys.org/news/2022-09-thermal-m ... power.html
by Bob Yirka , Phys.org

A team of researchers at Nankai University has developed a thermal management multi-layer material that responds to heat or cold by folding or unfolding itself without the need for an external power source. In their paper published in Proceedings of the National Academy of Sciences, the group describes how they came to develop the material and detail its performance when tested.

As scientists around the world work to develop alternative energy sources, others work on ways to use those that have already been developed—solar power, for example, or radiative cooling technologies. In this new effort, the researchers sought a way to shift a device between its use of solar heating or radiative cooling, automatically and without the need for a secondary power source.

For inspiration, the researchers turned to the Himalayan rabbit, which has fur that changes color depending on the season, and the leaves of the Mimosa pudica plant—its leaves open and close in reaction to changes in temperature. Their observations suggested that a material could be made that would behave similarly to the plant, allowing for switching between thermal devices.

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Engineers create the highest specific strength titanium alloy using 3D printing techniques
https://techxplore.com/news/2022-09-hig ... alloy.html
by Monash University

A world-first study led by Monash University engineers has demonstrated how cutting-edge 3D-printing techniques can be used to produce an ultra strong commercial titanium alloy—a significant leap forward for the aerospace, space, defense, energy and biomedical industries.

Australian researchers, led by Professor Aijun Huang and Dr. Yuman Zhu from Monash University, used a 3D-printing method to manipulate a novel microstructure. In doing so, they achieved unprecedented mechanical performance.

This research, published in Nature Materials, was undertaken on commercially available alloys and can be applied immediately.

"Titanium alloys require complex casting and thermomechanical processing to achieve the high strengths required for some critical applications. We have discovered that additive manufacturing can exploit its unique manufacturing process to create ultra strong and thermally stable parts in commercial titanium alloys, which may be directly implemented in service," Professor Huang says.

"After a simple post-heat treatment on a commercial titanium alloy, adequate elongation and tensile strengths over 1,600 MPa are achieved, the highest specific strength among all 3D printed metal to date. This work paves the way to fabricate structural materials with unique microstructures and excellent properties for broad applications."

In the past decade, 3D-printing has led a new era in metal fabrication due to its design freedom that can fabricate almost any geometrical part.

Titanium alloys are presently the leading 3D-printed metal components for the aerospace industry. However, most commercially available titanium alloys made by 3D-printing do not have satisfactory properties for many structural applications, especially their inadequate strength at room and elevated temperatures under harsh service conditions.

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Chemically bathed silkworm silk is 70% stronger than spider silk
By Nick Lavars
October 06, 2022
https://newatlas.com/materials/chemical ... ider-silk/

As one of the strongest materials known to science, spider silk regularly finds itself at the center of exciting engineering breakthroughs, and a new study involving a quick chemical bath could take this research into new terrain. Scientists have developed a novel treatment method for silkworm silk that alters its make up to boost its performance, with the finished product offering 70% greater strength than indomitable spider silk.

Scientists have been working to replicate the incredible properties of spider silk in some interesting ways. Farming spiders to produce the material in great quantities is one possibility, but their territorial nature doesn’t lend itself so well to these environments.

We’ve seen researchers make inroads by engineering bacteria to produce their own version of silk, and create synthetic versions of it with many of the same properties as spider silk. Some inventive advances have even involved feeding spiders graphene to make their silk stronger, or adding nanocrystals to make synthetic versions stronger and tougher than the real deal.

The silk that silkworms produce to build their cocoons is another point of interest in these research circles. Silkworm farming generates almost all commercially used silk around the world, but its lower durability than spider silk sees its use mostly limited to fashion and textiles. We’ve seen scientists address this by devising chemical treatments designed to make silkworm silk stiffer, and now a team from China’s Tianjin University has come up with a promising recipe of its own.

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New form of silicon could revolutionize semiconductor industry
https://phys.org/news/2022-10-silicon-r ... ustry.html
by Alena Kuzub, Northeastern University

After a 10-year research study that started by accident and was met with skepticism, a team of Northeastern University mechanical engineers was able to synthesize highly dense, ultra-narrow silicon nanowires that could revolutionize the semiconductor industry. Their research appears in Nature Communications.

Yung Joon Jung, Northeastern professor of mechanical and industrial engineering, says it might have been his favorite research project.

"Everything is new, and it required a lot of perseverance," says Jung, who specializes in engineering and application of nanostructure systems and previously studied carbon nanotubes.

Jung and his collaborators, including another Northeastern professor of mechanical engineering, Moneesh Upmanyu, have achieved a major advancement in nanowire synthesis by discovering a new, highly dense form of silicon and mastering a new, scalable catalyst-free etching process to produce ultra-small silicon nanowires of two to five nanometers in diameter.

About 10 years ago, students brought Jung's attention to an unusual result of an experiment they were conducting using silicon wafers. The material he saw under an electron microscope was different from the one they intended to produce, Jung says.

He decided to find out more about this substance and discovered that it was silicon with "a very, very tiny" wire-like nanostructure, Jung says. They were able to reproduce the new material, he says, but when they tried to improve the synthesis process the nanowires didn't grow.

The scientist and his team had to rewind and study, from the beginning, the synthesis mechanism and the material's atomic-scale structure and properties. Jung, an experimentalist, decided to enlist Upmanyu, who uses theory, computer modeling and simulation to understand materials and explain experiments.

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Researchers develop thermoformable ceramics, 'a new frontier in materials'
https://phys.org/news/2022-10-thermofor ... rials.html
by Ian Thomsen, Northeastern University

It was one of those happy accidents of science. Northeastern professor Randall Erb and Ph.D. student Jason Bice were working on a product for a university client—and wound up with an entirely new class of material.

Their discovery of an all-ceramic that can be compression-molded into complex parts—an industry breakthrough—could transform the design and construction of heat-emitting electronics, including cellphones and other radio components.

"Our research group's lives are very much situated at the bleeding edge of technology," says Erb, an associate professor of mechanical and industrial engineering who heads the DAPS Lab at Northeastern. "Things break a lot, and every once in a while one of those breaks turns out to be good fortune."

Last July, Erb was in his Northeastern lab with Bice, who has since earned a mechanical engineering Ph.D. They were testing an experimental ceramic compound as part of a hypersonic project for an industrial partner when something appeared to go wrong.

"We blasted it with a blowtorch and, while we were loading it, it unexpectedly deformed and fell out of the fixture," Erb says. "We looked at the sample on the floor thinking that it was a failure."

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Study opens door to new class of slippery, water-loving surfaces
https://phys.org/news/2022-10-door-clas ... faces.html
by Matt Shipman, North Carolina State University

Researchers have demonstrated that engineered surfaces can be hydrophilic—meaning they have a strong affinity for water—and yet extremely slippery. The work runs counter to conventional wisdom regarding the development of slippery materials, and suggests a new area of research for the field.

"This finding is counter-intuitive, since the longstanding view has been that slippery surfaces tend to be hydrophobic—they repel water," says Arun Kumar Kota, corresponding author of a paper on the work and an associate professor of mechanical and aerospace engineering at North Carolina State University.

"But we've now demonstrated a way to engineer the surface of materials that makes them both very slippery and hydrophilic, or SLIC, surfaces. We have some specific applications where we think this may be useful, but this is essentially an unexplored class of surfaces. A lot of work needs to be done to fully understand the scope of potential applications."

"We've also articulated exactly how these SLIC surfaces can be designed, so that other researchers can expand what appears to be a very promising field," Kota says.

Previous ways of engineering a solid surface to make it slippery tended to take one of three approaches. One approach was to texture the material to trap a layer of air against the surface, with that air pocket serving as a lubricant. The second approach was to texture the surface and trap a layer of liquid lubricant against the material that would allow it to slide past other liquids or solids. In both of these cases, damage to the texture of the surfaces due to repeated use makes them less slippery. Similarly, the loss of the gaseous or liquid lubricants over time also makes them less slippery.

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Safe, sustainable photo-on-demand synthesis of polypeptide precursors

by Kobe University
https://phys.org/news/2022-10-safe-sust ... ptide.html

In nature, there are animals that make fibers that are strong and elastic—for example, the thread that spiders produce to make webs. These fibers have a polypeptide structure and serve as inspiration for research into the development of functional materials.

Alpha (α)-amino acid N-carboxyanhydrides (NCAs) are precursors for artificial polypeptides. However, this compound decomposes easily, making it difficult to obtain commercially. Therefore, it is necessary to synthesize the right quantity of α-amino acid NCAs at the location and time that they are required.

NCAs are usually synthesized from plant-derived amino acids and phosgene. However, phosgene is extremely toxic and dangerous to use, leading to growing demand for new chemical compounds and reactions that can be substituted for it. Using the photo-on-demand phosgenation method that they previously developed, Associate Professor TSUDA Akihiko's research group at Kobe University's Graduate School of Science has succeeded in synthesizing NCA in a safe, inexpensive and simple manner from chloroform (a common organic solvent) and amino acid.

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Researchers turn asphaltene into graphene for composites
https://phys.org/news/2022-11-asphalten ... sites.html
by Mike Williams, Rice University

Asphaltenes, a byproduct of crude oil production, are a waste material with potential. Rice University scientists are determined to find it by converting the carbon-rich resource into useful graphene.

Muhammad Rahman, an assistant research professor of materials science and nanoengineering, is employing Rice's unique flash Joule heating process to convert asphaltenes instantly into turbostratic (loosely aligned) graphene and mix it into composites for thermal, anti-corrosion and 3D-printing applications.

The process makes good use of material otherwise burned for reuse as fuel or discarded into tailing ponds and landfills. Using at least some of the world's reserve of more than 1 trillion barrels of asphaltene as a feedstock for graphene would be good for the environment as well.

"Asphaltene is a big headache for the oil industry, and I think there will be a lot of interest in this," said Rahman, who characterized the process as both a scalable and sustainable way to reduce carbon emissions from burning asphaltene.

Rahman is a lead corresponding author of the paper in Science Advances co-led by Rice chemist James Tour, whose lab developed flash Joule heating, materials scientist Pulickel Ajayan and Md Golam Kibria, an assistant professor of chemical and petroleum engineering at the University of Calgary, Canada.

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Using machine learning to infer rules for designing complex mechanical metamaterials
https://phys.org/news/2022-11-machine-i ... rials.html
by Ingrid Fadelli , Phys.org

Mechanical metamaterials are sophisticated artificial structures with mechanical properties that are driven by their structure, rather than their composition. While these structures have proved to be very promising for the development of new technologies designing them can be both challenging and time-consuming.

Researchers at University of Amsterdam, AMOLF, and Utrecht University have recently demonstrated the potential of convolutional neural networks (CNNs), a class of machine learning algorithms, for designing complex mechanical metamaterials. Their paper, published in Physical Review Letters, specifically introduces two-different CNN-based methods that can derive and capture the subtle combinatorial rules underpinning the design of mechanical metamaterials.

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Going back to basics yields a printable, transparent plastic that's highly conductive
https://phys.org/news/2022-12-basics-yi ... astic.html
by Joshua Stewart, Georgia Institute of Technology

It was a simple idea—maybe even too simple to work.

Research scientist James Ponder and a team of Georgia Tech chemists and engineers thought they could design a transparent polymer film that would conduct electricity as effectively as other commonly used materials, while also being flexible and easy to use at an industrial scale.

They'd do it by simply removing the nonconductive material from their conductive element. Sounds logical, right?

The resulting process could yield new kinds of flexible, transparent electronic devices—things like wearable biosensors, organic photovoltaic cells, and virtual or augmented reality displays and glasses.

"We had this initial idea that we have a conductive element that we're covering with a nonconductive material, so what if we just get rid of that," said Ponder, who earned a Ph.D. in chemistry at Georgia Tech and returned as a research scientist in mechanical engineering. "It's a simple idea, and there were so many points where it could have failed for different reasons. But it does work, and it works better than we expected."

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Chip lets scientists study biocement formation in real-time
https://techxplore.com/news/2022-12-chi ... -time.html
by Sandrine Perroud, Ecole Polytechnique Federale de Lausanne

Scientists from EPFL and the University of Lausanne have used a chip that was originally designed for environmental science to study the properties of biocement formation. This material has the potential to replace traditional cement binders in certain civil engineering applications.

The chip is the size of a credit card and its surface is engraved with a flow channel measuring one meter from end to end that is as thick as a human hair. Researchers can inject a solution into one end of the channel and, with the help of time-lapse microscopy, observe the solution's behavior over several hours. Medical scientists have used similar chips for health care applications, such as to examine how arteries get clogged or how a drug spreads into the bloodstream, while environmental engineers have applied them to the study of biofilms and contaminants in drinking water.

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This Alloy Is the Toughest Known Material on Earth, And It Gets Tougher in The Cold
by Michelle Starr
December 11, 2022

Introduction:

(Science Alert) An alloy of chromium, cobalt, and nickel has just given us the highest fracture toughness ever measured in a material on Earth.

It has exceptionally high strength and ductility, leading to what a team of scientists has called "outstanding damage tolerance".

Moreover – and counterintuitively – these properties increase as the material gets colder, suggesting some interesting potential for applications in extreme cryogenic environments.

"When you design structural materials, you want them to be strong but also ductile and resistant to fracture," says metallurgist Easo George, Governor's Chair for Advanced Alloy Theory and Development at Oak Ridge National Laboratory and the University of Tennessee.

"Typically, it's a compromise between these properties. But this material is both, and instead of becoming brittle at low temperatures, it gets tougher."

Read more here: https://www.sciencealert.com/this-allo ... -the-cold

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Team creates protein-based material that can stop supersonic impacts
https://phys.org/news/2022-12-team-prot ... pacts.html
by Katherine Moss, University of Kent

A University of Kent team, led by Professors Ben Goult and Jen Hiscock, has created and patented a new shock-absorbing material that could revolutionize both the defense and planetary science sectors.

This novel protein-based family of materials, named TSAM (Talin Shock Absorbing Materials), represents the first known example of a SynBio (or synthetic biology) material capable of absorbing supersonic projectile impacts. This opens the door for the development of next-generation bulletproof armor and projectile capture materials to enable the study of hypervelocity impacts in space and the upper atmosphere (astrophysics).

Professor Ben Goult explained, "Our work on the protein talin, which is the cell's natural shock absorber, has shown that this molecule contains a series of binary switch domains which open under tension and refold again once tension drops. This response to force gives talin its molecular shock absorbing properties, protecting our cells from the effects of large force changes. When we polymerized talin into a TSAM, we found the shock absorbing properties of talin monomers imparted the material with incredible properties."

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GTUB3 is the first microporous, metal-organic solid that is both conductive and photoluminescent
https://phys.org/news/2022-12-gtub3-mic ... scent.html
by Technical University of Berlin

Researchers at TU Berlin have developed a new material from the class of microporous, metal-organic framework (MOF) compounds. On the one hand, such compounds can store small molecules and gases such as hydrogen, CO2 or even toxins. On the other hand, the large surface area resulting from the high volume of pores means they are also suitable as a material for electrodes such as in supercapacitors, which can be charged much faster than conventional batteries.

A study describing this work is published in the journal Advanced Optical Materials.

The problem to date is that the majority of MOFs are very poor conductors of electricity. The new material created by the researchers, called GTUB3, is both a good conductor as well as chemically and thermally extremely stable. What makes it unique is that it is also photoluminescent, meaning that it glows when irradiated with light. As a result, it could also be used in optoelectronic applications and solar cells.

Metal-organic frameworks, or MOFs, are considered one of the most exciting classes of materials in modern chemistry. They consist of metal atoms directly bonded to organic molecules. "In the past, we only valued such crystal structures for their aesthetic beauty. Some of them actually call to mind Moroccan tiles," explains Dr. Gündoğ Yücesan from Faculty III—Process Sciences at TU Berlin. "What makes them interesting today are the many cavities that make microporous MOFs ideal storage media as well as their large surfaces, which facilitate reactions."

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Exploring the problem of creating a plastic that is both strong and biodegradable
https://phys.org/news/2022-12-exploring ... dable.html
by University of Konstanz

How can plastics be designed so they retain their desirable properties but at the same time can be more effectively recycled? This and other questions concerning the eco-friendliness of plastics are the focus of chemist Stefan Mecking and his research group at the University of Konstanz.

In their latest paper in the international edition of Angewandte Chemie, the team presents a new polyester that exhibits material properties that are attractive for industry while being environmentally friendly.

Normally incompatible

Plastics are made of long chains of one or several chemical basic modules, so-called monomers. Plastics distinguished by high crystallinity and water repellency, which are therefore mechanically highly resilient and stable, are widely used. A well-known example is high density polyethylene (HDPE), whose basic modules consist of non-polar hydrocarbon molecules.

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Enzymes could make it cheaper to recycle waste polyester textiles and bottles than making them from petroleum
https://techxplore.com/news/2022-12-enz ... tiles.html
by Erik F. Ringle, National Renewable Energy Laboratory

What do a T-shirt, a rug, and a soda bottle have in common? Many are made from polyethylene terephthalate (PET), a ubiquitous plastic that revolutionized the materials industry after it was patented in the 1940s.

Created from petroleum refining, PET is a material known for its durability and versatility. It is easily molded into airtight containers, woven into durable carpets, or spun into polyester clothing.

"The reality is that most PET products—especially PET clothing and carpeting—are not recycled today using conventional recycling technologies," explained Gregg Beckham, senior research fellow at the National Renewable Energy Laboratory (NREL) and CEO of the U.S. Department of Energy BOTTLE Consortium. "The research community is developing promising alternatives, including enzymes designed to depolymerize PET, but even these options have tended to lean on energy-intensive and costly preprocessing steps to be effective."

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'Smart' coating can be precisely applied to make fabric into protective gear
https://phys.org/news/2023-01-smart-coa ... -gear.html
by Morgan Kelly, Dartmouth College

A durable copper-based coating developed by Dartmouth College researchers can be precisely integrated into fabric to create responsive and reusable materials such as protective equipment, environmental sensors, and smart filters, according to a recent study.

The coating responds to the presence of toxic gases in the air by converting them into less toxic substances that become trapped in the fabric, the team reports in the Journal of the American Chemical Society (JACS).

The findings hinge on a conductive metal-organic technology, or framework, developed in the laboratory of corresponding author Katherine Mirica, an associate professor of chemistry at Dartmouth. First reported in JACS in 2017, the framework was a simple coating that could be layered onto cotton and polyester to create smart fabrics the researchers named SOFT—Self-Organized Framework on Textiles. Their paper demonstrated that SOFT smart fabrics could detect and capture toxic substances in the surrounding environment.

For the newest study, the researchers found that—instead of the simple coating reported in 2017—they can precisely embed the framework into fabrics using a copper precursor that allows them to create specific patterns and more effectively fill in the tiny gaps and holes between threads.

The researchers found that the framework technology effectively converted the toxin nitric oxide into nitrite and nitrate, and transformed the poisonous, flammable gas hydrogen sulfide into copper sulfide. They also report that the framework's ability to capture and convert toxic materials withstood wear and tear, as well as standard washing.

The versatility and durability the new method provides would allow the framework to be applied for specific uses and in more precise locations, such as a sensor on protective clothing, or as a filter in a particular environment, Mirica said.

"This new method of deposition means that the electronic textiles could potentially interface with a broader range of systems because they're so robust," she said. "This technological advance paves the way for other applications of the framework's combined filtration and sensing abilities that could be valuable in biomedical settings and environmental remediation."

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Chemical researchers discover catalyst to make renewable paints, coatings, and diapers
https://phys.org/news/2023-01-chemical- ... apers.html
by University of Minnesota

A team led by University of Minnesota Twin Cities researchers has invented a groundbreaking new catalyst technology that converts renewable materials like trees and corn to the key chemicals, acrylic acid, and acrylates used in paints, coatings, and superabsorbent polymers. The new catalyst technology is also highly efficient, which means lower costs for manufacturing renewable chemicals.

The new catalyst formulation converts lactic acid-based chemicals derived from corn to acrylic acid and acrylates with the highest yield achieved to date. The technology exhibits substantially higher performance when benchmarked against other classes of leading catalysts.

The research is published online in the JACS Au.

The public is most familiar with acrylic acid and associated acrylates through its uses in everyday items from paints and coatings to sticky adhesives to superabsorbent materials used in diapers. These chemicals and materials have been made for the last century from fossil fuels. But in the last few decades, the corn industry has been growing to expand beyond food and livestock feed to manufacturing useful chemicals.

One such corn-derived chemical is sustainable lactic acid, a key ingredient in the manufacturing of the renewable and compostable plastic used in many everyday applications.

Lactic acid can also be converted to acrylic acid and acrylates using catalysts. However, until this new catalyst discovery, traditional catalysts were very inefficient achieving low yields and making the overall process too expensive.

"Our new catalyst formulation discovery achieves the highest yield to date of acrylic acid from lactic acid," said Paul Dauenhauer, professor in the University of Minnesota Department of Chemical Engineering and Materials Science. "We benchmarked the performance of our new catalyst to all prior catalysts, and the performance far exceeds previous examples."

The new catalyst formulation substantially reduces the cost of manufacturing renewable acrylic acid and acrylates from corn by improving yield and reducing waste. For the first time, this could reduce the price of renewable acrylic acid below fossil-derived chemicals.

The economic opportunity generated by the new catalyst is being pursued by Låkril Technologies, a startup company that aims to manufacture low-cost renewable acrylic acid and acrylates. By licensing the catalyst technology from the University of Minnesota, Låkril Technologies will develop the technology beyond the laboratory.

"Chemical manufacturing has relied on a class of catalysts called 'zeolites' for half a century," says Dr. Chris Nicholas, CEO of Låkril Technologies. "Because the new catalyst discovery is based on a zeolite formulation already available at scale, our new process to make acrylic acid and acrylates will achieve low cost with low risk."

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US company gets $120 million boost to make 'green steel'
Source: AP

By ED DAVEY today

The manufacture of “green steel” moved one step closer to reality Friday as Massachusetts-based Boston Metal announced a $120 million investment from the world’s second-largest steelmaker, ArcelorMittal.

Boston Metal will use the injection of funds to expand production at a pilot plant in Woburn, near Boston, and help launch commercial production in Brazil. The company uses renewable electricity to convert iron ore into steel.

Steel is one of the world’s dirtiest heavy industries. Three-quarters of world production uses a traditional method that burns through train loads of coal to heat the furnaces and drive the reaction that releases pure iron from ore.

Making steel releases more climate-warming carbon dioxide than any other industry, according to the International Energy Agency — about 8% of worldwide emissions. Many companies are working on alternatives.

Read more: https://apnews.com/article/production-f ... 316007f994

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Novel technique developed to produce hydrogen peroxide without emitting carbon dioxide
https://phys.org/news/2023-01-technique ... arbon.html
by Ricardo Muniz, FAPESP

A study published in ACS Applied Materials & Interfaces describes a novel method of producing hydrogen peroxide (H2O2) without emitting carbon dioxide (CO2), one of the main greenhouse gases and one of the world's most widely produced chemicals.

Hydrogen peroxide is used to bleach fabric, pulp and paper, and to whiten teeth. It is also used as a thruster fuel for satellite attitude control, and as a disinfectant or sterilizing agent by hospitals. Some 2 million metric tons of the compound are produced annually.

"To understand the impact of our findings, it's important first and foremost to bear in mind the significance of H2O2 in the chemical industry and the way it's currently produced," said Ivo Freitas Teixeira, a professor of chemistry at the Federal University of São Carlos (UFSCar) in São Paulo State, Brazil. He has a Ph.D. in inorganic chemistry from the University of São Paulo (USP) and was a Humboldt Fellow at the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany, between 2019 and 2021.