. Scientific Frontline: Chemistry
Showing posts with label Chemistry. Show all posts
Showing posts with label Chemistry. Show all posts

Tuesday, September 27, 2022

To Stop Viruses, SDSU Researchers are Figuring Out How They're Built

Multiple protein subunits (green, purple and red) of a plant-infecting virus have separate nucleation and growth phases similar to the MS2 bacteria-infecting virus (right).
Source: Protein Data Bank.

An SDSU team, along with Harvard and UCLA collaborators, are researching how distantly related viruses self-organize to improve disease-fighting tactics.

Without a multi-page instruction manual or a commanding Captain America, how do viruses assemble hundreds of individual pieces into elaborate structures capable of spreading disease?

Solving the secret of self-assembly can pave the way for engineering advancements like molecules and robots that put themselves together. It could also contribute to more efficient packaging, automated delivery and targeted design of medicine in the fight against viruses that cause colds, diarrhea, liver cancer and polio.

“If we understand the physical rules of how viruses assemble, then we can try to make them form incorrect structures to hinder their spread,” said Rees Garmann, a chemist at San Diego State University and lead author of a new paper published in the journal PNAS that fills in a piece of the puzzle.

Friday, September 23, 2022

DNA nets capture COVID-19 virus in low-cost rapid-testing platform

Tiny nets woven from DNA strands cover the spike proteins of the virus that causes COVID-19 and give off a glowing signal in this artist’s rendering. 
Image courtesy of Xing Wang

Tiny nets woven from DNA strands can ensnare the spike protein of the virus that causes COVID-19, lighting up the virus for a fast-yet-sensitive diagnostic test – and also impeding the virus from infecting cells, opening a new possible route to antiviral treatment, according to a new study.

Researchers at the University of Illinois Urbana-Champaign and collaborators demonstrated the DNA nets’ ability to detect and impede COVID-19 in human cell cultures in a paper published in the Journal of the American Chemical Society.

“This platform combines the sensitivity of clinical PCR tests and the speed and low cost of antigen tests,” said study leader Xing Wang, a professor of bioengineering and of chemistry at Illinois. “We need tests like this for a couple of reasons. One is to prepare for the next pandemic. The other reason is to track ongoing viral epidemics – not only coronaviruses, but also other deadly and economically impactful viruses like HIV or influenza.”

DNA is best known for its genetic properties, but it also can be folded into custom nanoscale structures that can perform functions or specifically bind to other structures much like proteins do. The DNA nets the Illinois group developed were designed to bind to the coronavirus spike protein – the structure that sticks out from the surface of the virus and binds to receptors on human cells to infect them. Once bound, the nets give off a fluorescent signal that can be read by an inexpensive handheld device in about 10 minutes.

Fighting fungal infections with metals

A Petri dish with red agar on which grows a fungal strand in the shape of the element symbol for platinum (Pt).
Credit: CO-ADD

An international collaboration led by researchers from the University of Bern and the University of Queensland in Australia has demonstrated that chemical compounds containing special metals are highly effective in fighting dangerous fungal infections. These results could be used to develop innovative drugs which are effective against resistant bacteria and fungi.

Each year, more than one billion people contract a fungal infection. Although they are harmless to most people, over 1.5 million patients die each year as a result of infections of this kind. While more and more fungal strains are being detected that are resistant to one or more of the available drugs, the development of new drugs has come to a virtual standstill in recent years. Today, only around a dozen clinical trials are underway with new active agents for the treatment of fungal infections. “In comparison with more than a thousand cancer drugs that are currently being tested on human subjects, this is an exceptionally small number,” explains Dr. Angelo Frei of the Department of Chemistry, Biochemistry and Pharmacy at the University of Bern, lead author of the study. The results have been published in the journal JACS Au.

Boosting antibiotics research with crowd sourcing

The CO-ADD Team at work in the laboratory.
Credit: CO-ADD

To encourage the development of anti-fungal and antibacterial agents, researchers at the University of Queensland in Australia have founded the Community for Open Antimicrobial Drug Discovery, or CO-ADD. The ambitious goal of the initiative is to find new antimicrobial active agents by offering chemists worldwide the opportunity to test any chemical compound against bacteria and fungi at no cost. As Frei explains, the initial focus of CO-ADD has been on “organic” molecules, which mainly consist of the elements of carbon, hydrogen, oxygen and nitrogen, and do not contain any metals.

However, Frei, who is trying to develop new metal-based antibiotics with his research group at the University of Bern, has found that over 1,000 of the more than 300,000 compounds tested by CO-ADD contained metals. “For most folks, when used in connection with the word ‘people’, the word metal triggers a feeling of unease. The opinion that metals are fundamentally harmful to us is widespread. However, this is only partially true. The decisive factor is which metal is used and in which form,” explains Frei, who is responsible for all the metal compounds in the CO-ADD database.

Low toxicity demonstrated

Dr. Angelo Frei at work in the laboratory.
Credit: Angelo Frei

In their new study, the researchers turned their attention to the metal compounds which showed activity against fungal infections. Here, 21 highly-active metal compounds were tested against various resistant fungal strains. These contained the metals cobalt, nickel, rhodium, palladium, silver, europium, iridium, platinum, molybdenum and gold. “Many of the metal compounds demonstrated a good activity against all fungal strains and were up to 30,000 times more active against fungi than against human cells,” explains Frei. The most active compounds were then tested in a model organism, the larvae of the wax moth. The researchers observed that just one of the eleven tested metal compounds showed signs of toxicity, while the others were well tolerated by the larvae. In the next step, some metal compounds were tested in an infection model, and one compound was effective in reducing the fungal infection in larvae.

Considerable potential for broad application

Metal compounds are not new to the world of medicine: Cisplatin, for example, which contains platinum, is one of the most widely used anti-cancer drugs. Despite this, there is a long way to go before new antimicrobial drugs that contain metals can be approved. “Our hope is that our work will improve the reputation of metals in medical applications and motivate other research groups to further explore this large but relatively unexplored field,” says Frei. “If we exploit the full potential of the periodic table, we may be able to prevent a future where we don’t have any effective antibiotics and active agents to prevent and treat fungal infections.”

The study was supported by the Swiss National Science Foundation, the Wellcome Trust and the University of Queensland, among others.

Source/Credit: University of Bern

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Thursday, September 22, 2022

Atomic-Scale Imaging Reveals a Facile Route to Crystal Formation

Aluminum hydroxide, depicted here in orange, undergoes fluctuations between structures before forming an ordered crystal. 
Illustration by Nathan Johnson | Pacific Northwest National Laboratory

What do clouds, televisions, pharmaceuticals, and even the dirt under our feet have in common? They all have or use crystals in some way. Crystals are more than just fancy gemstones. Clouds form when water vapor condenses into ice crystals in the atmosphere. Liquid crystal displays are used in a variety of electronics, from televisions to instrument panels. Crystallization is an important step for drug discovery and purification. Crystals also make up rocks and other minerals. Their crucial role in the environment is a focus of materials science and health sciences research.

Scientists have yet to fully understand how crystallization occurs, but the importance of surfaces in promoting the process has long been recognized. Research from Pacific Northwest National Laboratory (PNNL), the University of Washington (UW), and Durham University sheds new light on how crystals form at surfaces. Their results were published in Science Advances.

Previous studies on crystallization led scientists to form the classical nucleation theory—the predominant explanation for why crystals begin to form, or nucleate. When crystals nucleate, they begin as very small ephemeral clusters of just a few atoms. Their small size makes the clusters extremely difficult to detect. Scientists have managed to collect only a few images of such processes.

Monday, September 19, 2022

New Way to Obtain High-Productivity Proton Conductors Found

Natalya Tarasova works on the creation of new proton conductors.
Photo credit: Ilya Safarov.

Scientists from the Ural Federal University and the Institute of High Temperature Electrochemistry of the Ural Branch of the Russian Academy of Sciences carried out the first demonstration of donor and acceptor doping of perovskite with a barium-lanthanum indite block-layer structure. The fundamental possibility of such a method to significantly improve the conducting properties of the material was shown. The work opens a new way to the creation of solid oxide fuel cell electrolytes. An article describing the research and its results was published in Ceramics International.

One of the goals of global materials science is to obtain the highest possible electrical conductivity of electrolytes for their further use in solid oxide fuel cells. For this purpose, doping is the replacement of part of the atoms in the starting materials by atoms of another chemical element (acceptor doping is replacement by atoms with a lower valence, donor doping is replacement by atoms with a higher valence).

"We used barium-lanthanum iodate as the initial structure and during our studies we substituted some indium atoms for titanium (donor doping) and some lanthanum atoms for calcium (acceptor doping) in it. When acceptor doping, oxygen defects - oxygen vacancies - appeared in the crystal lattice of the initial material. This can ensure the transfer of protons - positively charged hydrogen ions - along the crystal lattice. They get into the structure of layered perovskite from humidified air at 300-500°C. The more oxygen defects and, consequently, the greater the concentration of protons in the perovskite crystal lattice and their mobility, i.e. speed, the higher the values of the electrical conductivity of the material," explains Natalya Tarasova, Professor of the Department of Physical Chemistry and Leading Researcher of the Institute of Hydrogen Energy at UrFU.

Wednesday, September 14, 2022

Pioneering research using bacteria brings scientists a step closer to creating artificial cells with lifelike functionality

Amoeba-shaped bacteriogenic protocell: membrane (red boundary); nucleus (blue); cytoskeleton (red filaments); vacuole (red circle); ATP production (green). Scale bar, 5 μm.
Credit: Professor Stephen Mann and Dr Can Xu

Scientists have harnessed the potential of bacteria to help build advanced synthetic cells which mimic real life functionality.

The research, led by the University of Bristol and published today in Nature, makes important progress in deploying synthetic cells, known as protocells, to more accurately represent the complex compositions, structure, and function of living cells.

Establishing true-to-life functionality in protocells is a global grand challenge spanning multiple fields, ranging from bottom-up synthetic biology and bioengineering to origin of life research. Previous attempts to model protocells using microcapsules have fallen short, so the team of researchers turned to bacteria to build complex synthetic cells using a living material assembly process.

Professor Stephen Mann from the University of Bristol’s School of Chemistry, and the Max Planck Bristol Centre for Minimal Biologytogether with colleagues Drs Can Xu, Nicolas Martin (currently at the University of Bordeaux) and Mei Li in the Bristol Centre for Protolife Research have demonstrated an approach to the construction of highly complex protocells using viscous micro-droplets filled with living bacteria as a microscopic building site.

Water can be liquid, gas or ice, right? Think again

Credit: Daniel Sonoca

Scientists at the University of Cambridge have discovered that water in a one-molecule layer acts like neither a liquid nor a solid, and that it becomes highly conductive at high pressures.

Much is known about how ‘bulk water’ behaves: it expands when it freezes, and it has a high boiling point. But when water is compressed to the nanoscale, its properties change dramatically.

By developing a new way to predict this unusual behavior with unprecedented accuracy, the researchers have detected several new phases of water at the molecular level.

Water trapped between membranes or in tiny nanoscale cavities is common – it can be found in everything from membranes in our bodies to geological formations. But this nanoconfined water behaves very differently from the water we drink.

Until now, the challenges of experimentally characterizing the phases of water on the nanoscale have prevented a full understanding of its behavior. But in a paper published in the journal Nature, the Cambridge-led team describe how they have used advances in computational approaches to predict the phase diagram of a one-molecule thick layer of water with unprecedented accuracy.

They used a combination of computational approaches to enable the first-principles level investigation of a single layer of water.

Tuesday, September 13, 2022

Live Intracellular Imaging with New, Conditionally Active Immunofluorescence Probe

Figure 1
Schematic (a) and mechanism (c) of p53 Intra Q-body. (b) p53-dependent fluorescence signal and (d) microscopy images. (a) The double labelled fluorescent dye in the antigen fragment-based Q-body is de-quenched on binding with the target antigen, thus displaying fluorescent signaling for visualizing the intracellular target. (b) p53 peptide concentration-dependent variation in fluorescence signal intensity. (c) Q-body displays a high fluorescent signal on binding with the target in cells expressing p53, as compared to the 'p53' negative human cells. (d) Confocal microscopy images of HCT116 p53 and SK-BR-3. Cells which do not express p53, i.e., HCT116 p53(-/-) exhibit no TAMRA-based fluorescence while others (including images stained with Hoechst dye for illuminating nucleus and under bright-field to show the cells) display significant fluorescence.
Source/Credit: Tokyo Institute of Technology

Furthering the visualization of intracellular dynamics for therapeutic applications, a Tokyo Tech research team has now demonstrated precise imaging of endogenous proteins in live cells using an antigen-binding fragment (Fab)-based Quenchbody (Q-body). The Q-body probe shows antigen-dependent response and a switchable (on-off) fluorescent signaling, enabling the visualization and sorting of cells expressing p53, a tumor suppressor biomarker protein.

Recent advances in imaging technology have made it possible to visualize intracellular dynamics, which offers a better understanding of several key biological principles for accelerating therapeutic development. Fluorescent labeling is one such technique that is used to identify intracellular proteins, their dynamics, and dysfunction. Both internal as well as external probes with fluorescent dyes are used for this purpose, although external probes can better visualize intracellular proteins as compared to the internal probes. However, their application is limited by non-specific binding to intracellular components, resulting in a low target specific signaling and higher background noise.

Sunday, September 11, 2022

Researchers develop plastic film that can kill viruses using room lights

Credit: Queen's University Belfast

The self-sterilizing film is the first of its kind – it is low cost to produce, can be readily scaled and could be used for disposable aprons, tablecloths, and curtains in hospitals.

It is coated with a thin layer of particles that absorb UV light and produce reactive oxygen species – ROS. These kill viruses, including SARS2.

The technology used to create the film also ensures it is degradable - unlike the current disposable plastic films it would replace, which is much more environmentally friendly.

The breakthrough could lead to a significant reduction in the transmission of viruses in healthcare environments but also in other settings that use plastic films – for example, food production factories.

The Queen’s researchers tested the film for anti-viral activity using four different viruses – two strains of influenza A virus, a highly-stable picornavirus called EMCV and SARS2 – exposing it to either UVA radiation or with light from a cool white light fluorescent lamp.

They found that the film is effective at killing all of the viruses - even in a room lit with just white fluorescent tubes.

Friday, September 9, 2022

A breakthrough discovery in carbon capture conversion for ethylene production

 Abstract illustration of atoms passing through water and an electrified membrane under a shining sun.
Credit: Meenesh Singh

A team of researchers led by Meenesh Singh at University of Illinois Chicago has discovered a way to convert 100% of carbon dioxide captured from industrial exhaust into ethylene, a key building block for plastic products.

Their findings are published in Cell Reports Physical Science.

While researchers have been exploring the possibility of converting carbon dioxide to ethylene for more than a decade, the UIC team’s approach is the first to achieve nearly 100% utilization of carbon dioxide to produce hydrocarbons. Their system uses electrolysis to transform captured carbon dioxide gas into high purity ethylene, with other carbon-based fuels and oxygen as byproducts.

The process can convert up to 6 metric tons of carbon dioxide into 1 metric ton of ethylene, recycling almost all carbon dioxide captured. Because the system runs on electricity, the use of renewable energy can make the process carbon negative.

According to Singh, his team’s approach surpasses the net-zero carbon goal of other carbon capture and conversion technologies by actually reducing the total carbon dioxide output from industry. “It’s a net negative,” he said. “For every 1 ton of ethylene produced, you’re taking 6 tons of CO2 from point sources that otherwise would be released to the atmosphere.”

Thursday, September 8, 2022

A bio-based solvent for paints and varnishes

In this apparatus, the production of the new solvent dimethylfuran is being tested on a small scale at the RUB.
Credit: Mareile Silvia Rohlf

So far, only a small part of the established solvents has been bio-based. The project team wants to change that - rethinking the entire process chain from start to finish.

Around 20 million tons of solvents are consumed worldwide every year, of which only a small part has been produced bio-based to date. An international project team wants to provide an alternative to established solvents with dimethylfuran. The substance is bio-based and biodegradable. The Ruhr University Bochum (RUB), the Fraunhofer Institute for Interfacial and Bioprocess Engineering IGB in Straubing and the industrial partner AURO Plant Chemistry AG are cooperating for the project. The German Research Foundation is funding the project from October 2022 to September 2025 with 214,200 euros.

The starting point for the work is the substance 5-hydroxymethylfurfural (HMF), which can be obtained from biomass and converted into dimethylfuran (DMF). Researchers at RUB around Prof. Dr. Martin Muhler and Dr. Baoxiang Peng from the Chair of Technical Chemistry has already been established in a previous project. In the current research project, they want to optimize the catalyst and the reaction conditions in order to lay the foundation for an industrial production of DMF. The IGB team around Dr. Harald Strittmatter and Ferdinand Vogelgsang from the innovation fields "Bioinspired Chemistry" and "Sustainable Catalytic Processes" will scale up the catalytic reaction to a 40-fold larger scale. Together with the industrial partner AURO, the scientists will finally provide ready-made recipes for the use of DMF as a solvent and test them in the production of natural colors.

Thursday, September 1, 2022

Recycling Greenhouse Gases

Florian Schrenk (left) and Christoph Rameshan
Source/Credit: Technische Universität Wien

CO2 and methane can be turned into valuable products. But until now the catalysts required for such reactions quickly lose their effectiveness. TU Wien has now developed more stable alternatives.

Wherever the production of harmful greenhouse gases cannot be prevented, they should be converted into something useful: this approach is called "carbon capture and utilization". Special catalysts are needed for this. Until now, however, the problem has been that a layer of carbon quickly forms on these catalysts - this is called "coking" - and the catalyst loses its effect. At TU Wien, a new approach was taken: tiny metallic nanoparticles were produced on perovskite crystals through special pre-treatment. The interaction between the crystal surface and the nanoparticles then ensures that the desired chemical reaction takes place without the dreaded coking effect.

Dry reforming: Greenhouse gases become synthesis gas

Carbon dioxide (CO2) and methane are the two human-made greenhouse gases that contribute most to climate change. Both gases often occur in combination, for example in biogas plants. "So-called methane dry reforming is a method that can be used to convert both gases into useful synthesis gas at the same time," says Prof. Christoph Rameshan from the Institute of Materials Chemistry at TU Wien. "Methane and carbon dioxide are turned into hydrogen and carbon monoxide - and it is then relatively easy to produce other hydrocarbons from them, right up to biofuels."

Scientists discover surprise anticancer properties of common lab molecule

Nobel laureate Dr. Aziz Sancar at an event in 2016.
Photo credit: Jon Gardiner/UNC-Chapel Hill

Scientists at the UNC School of Medicine have made the surprising discovery that a molecule called EdU, which is commonly used in laboratory experiments to label DNA, is in fact recognized by human cells as DNA damage, triggering a runaway process of DNA repair that is eventually fatal to affected cells, including cancer cells.

The discovery, published in the Proceedings of the National Academy of Sciences, points to the possibility of using EdU as the basis for a cancer treatment, given its toxicity and its selectivity for cells that divide fast.

“The unexpected properties of EdU suggest it would be worthwhile to conduct further studies of its potential, particularly against brain cancers,” said study senior author Dr. Aziz Sancar, the Sarah Graham Kenan Professor of Biochemistry and Biophysics at the UNC School of Medicine and member of the UNC Lineberger Comprehensive Cancer Center. “We want to stress that this is a basic but important scientific discovery. The scientific community has much work ahead to figure out if EdU could actually become a weapon against cancer.”

EdU (5-ethynyl-2′-deoxyuridine) is essentially a popular scientific tool first synthesized in 2008 as an analog, or chemical mimic, of the DNA building block thymidine – which represents the letter “T” in the DNA code of adenine (A), cytosine (C), guanine (G) and thymine (T). Scientists add EdU to cells in lab experiments to replace the thymidine in DNA. Unlike other thymidine analogs, it has a convenient chemical “handle” to which fluorescent probe molecules will bond tightly. It thus can be used relatively easily and efficiently to label and track DNA, for example in studies of the DNA replication process during cell division.

Wednesday, August 31, 2022

"Greener" Fertilizer and Carbon-free Fuels Come Closer to Reality

Photo by Richard Bell on Unsplash

A little over 100 years ago, humankind learned how to take nitrogen from the atmosphere (where it is plentiful) and turn it into ammonia that can be used as source of fertilizer for growing food. That chemical process, known as nitrogen fixation, has allowed huge increases in crop production and a subsequent boom in human populations fed by those crops.

Nearly all artificial nitrogen fixation is done with what is known as the Haber–Bosch process, which uses a metal catalyst to combine gaseous nitrogen and hydrogen into ammonia, at high pressures and temperatures. Ammonia fixed through this process is estimated to be responsible for growing crops that feed half the world's population.

But there is another large source of nitrogen fixation: bacteria that live in soil, which fix nitrogen at normal atmospheric temperatures and pressures. In recent decades, researchers searching for sustainable agriculture practices have looked to these microbes as inspiration for developing nitrogen-fixation processes that are easier to conduct and more environmentally friendly than the energy-intensive Haber-Bosch process. Now, a team at Caltech led by Jonas Peters, Bren Professor of Chemistry and director of the Resnick Sustainability Institute, has made a breakthrough that increases the efficiency of one of these low-temperature and low-pressure processes, further opening the door to greener fertilizer, and even the production of zero-carbon fuels.

Monday, August 22, 2022

Plastic Upcycling: From Waste to Fuel for Less

Plastic upcycling provides a way to reuse the waste carbon now cluttering landfills and beaches.
 Animation by Sara Levine | Pacific Northwest National Laboratory

A plastics recycling innovation that does more with less, presented today at the American Chemical Society fall meeting in Chicago, simultaneously increases conversion to useful products while using less of the precious metal ruthenium.

“The key discovery we report is the very low metal load,” said Pacific Northwest National Laboratory chemist Janos Szanyi, who led the research team. “This makes the catalyst much cheaper.”

The new method more efficiently converts plastics to valuable commodity chemicals—a process termed “upcycling.” In addition, it produces much less methane, an undesirable greenhouse gas, as a byproduct, compared with other reported methods.

“It was very interesting to us that there had been nothing previously published showing this result,” said postdoctoral research scientist Linxiao Chen, who presented the research at ACS. “This research shows the opportunity to develop effective, selective and versatile catalysts for plastic upcycling.”

Efficient Carbon Dioxide Reduction under Visible Light with a Novel, Inexpensive Catalyst


A novel coordination polymer-based photocatalyst for CO2 reduction exhibits unprecedented performance, giving scientists at Tokyo Tech hope in the fight against global warming. Made from abundant elements and requiring no complex post-synthesis treatment or modifications, this promising photocatalyst could pave the way for a new class of photocatalysts for efficiently converting CO2 into useful chemicals.

The carbon dioxide (CO2) released into the atmosphere during fossil fuel burning is a leading cause of global warming. One way to address this growing threat is to develop CO2 reduction technologies, which convert CO2 into useful chemicals, such as CO and formic acid (HCOOH). In particular, photocatalytic CO2 reduction systems use visible or ultraviolet light to drive CO2 reduction, much like how plants use sunlight to conduct photosynthesis. Over the past few years, scientists have reported many sophisticated photocatalysts based on metal-organic frameworks and coordination polymers (CPs). Unfortunately, most of them either require complex post-synthesis treatment and modifications or are made from precious metals.

In a recent study published in ACS Catalysis, a research team Japan found a way to overcome these challenges. Led by Specially Appointed Assistant Professor Yoshinobu Kamakura and Professor Kazuhiko Maeda from Tokyo Institute of Technology (Tokyo Tech), the team developed a new kind of photocatalyst for CO2 reduction based on a CP containing lead–sulfur (Pb–S) bonds. Known as KGF-9, the novel CP consists of an infinite (–Pb–S–) n structure with properties unlike any other known photocatalyst.

Friday, August 19, 2022

‘Forever chemicals’ destroyed by simple new method

Water samples for PFAS analysis.
Credit: Michigan Department of Environment, Great Lakes and Energy

PFAS, a group of manufactured chemicals commonly used since the 1940s, are called “forever chemicals” for a reason. Bacteria can’t eat them; fire can’t incinerate them; and water can’t dilute them. And, if these toxic chemicals are buried, they leach into surrounding soil, becoming a persistent problem for generations to come.

Now, Northwestern University chemists have done the seemingly impossible. Using low temperatures and inexpensive, common reagents, the research team developed a process that causes two major classes of PFAS compounds to fall apart — leaving behind only benign end products.

The simple technique potentially could be a powerful solution for finally disposing of these harmful chemicals, which are linked to many dangerous health effects in humans, livestock and the environment.

The research is published in the journal Science.

“PFAS has become a major societal problem,” said Northwestern’s William Dichtel, who led the study. “Even just a tiny, tiny amount of PFAS causes negative health effects, and it does not break down. We can’t just wait out this problem. We wanted to use chemistry to address this problem and create a solution that the world can use. It’s exciting because of how simple — yet unrecognized — our solution is.”

University Scientists Found Out How to Efficiently Extract Silver

Yulia Petrova is engaged in the selection of sorbents in the Laboratory of Chemical Design for New Multifunctional Oxide Materials.
Photo credit: Daniil Kovalenko

Chemists at Ural Federal University have identified the best sorbent based on aminopolymers modified with sulfoethyl groups for the extraction of silver ions from multicomponent solutions. The results of the research lead to the production of sorbents for the extraction of metals which concentration in solutions is insignificant. The obtained sorbents are potentially applicable, for example, in the purification of natural drinking water, fish ponds, and in the processing of industrial waste. The research was supported financially by the Russian Science Foundation (grant № 21-73-00052) and is described in a scientific article published in the Russian Journal of Inorganic Chemistry.

"Sorption of metal ions is facilitated by the very nature of the aminopolymer matrix of the sorbents. Adding sulfoethyl groups to it, as our studies show, leads to a significant increase in the selective properties of sorbents, that is the ability to absorb only certain ions from a wide set of different ions. The higher the degree of modification of sorbents by sulfoethyl groups, i.e. the more sulfoethyl groups in their composition, the better their selective properties. This particular work is dedicated to studying the extraction rate of silver ions from multicomponent solutions in the presence of copper, nickel, cobalt, zinc, and several other metals," says Yulia Petrova, Head of the research group and Associate Professor at the Department of Analytical and Environmental Chemistry at UrFU.

Wednesday, August 10, 2022

Eco-glue can replace harmful adhesives in wood construction

Plywood with eco-glue produced in Aalto University.
Photo Credit: Aalto University

A fast and energy-efficient manufacturing process results in a strong, non-toxic and fire-resistant adhesive—and a great opportunity for the Finnish bioeconomy.

Researchers at Aalto University have developed a bio-based adhesive that can replace formaldehyde-containing adhesives in wood construction. The main raw material in the new adhesive is lignin, a structural component of wood and a by-product of the pulp industry that is usually burned after wood is processed. As an alternative to formaldehyde, lignin offers a healthier and more carbon-friendly way to use wood in construction.

The carbon footprint of timber construction is significantly lower than concrete construction, and timber construction has often been viewed as better for the health of human occupants as well. However, wood panels still use adhesives made from fossil raw materials. They contain formaldehyde, which can be harmful to health, especially for those working in the adhesive manufacturing process. People living in or visiting buildings can also be exposed to toxic formaldehyde from wood panels.

Lignin, on the other hand, comes from wood itself. It binds cellulose and hemicellulose together and gives wood its tough, strong structure. Lignin accounts for about a quarter of the weight of wood and is produced in huge quantities in the pulp and bioprocessing industry. Only two to five percent of the lignin produced is used, and the rest is burned in factories for energy.

Tuesday, August 9, 2022

In control of chaos

Assembly line: A different chemical mixture is created in each of the droplets within the "Tubular flow reactor" – under exactly the same boundary conditions.
Image Credit: Empa

Crystals consisting of wildly mixed ingredients - so-called high-entropy materials - are currently attracting growing scientific interest. Their advantage is that they are particularly stable at extremely high temperatures and could be used, for example, for energy storage and chemical production processes. An Empa team is producing and researching these mysterious ceramic materials, which have only been known since 2015.

Nature strives for chaos. That's a nice, comforting phrase when yet another coffee cup has toppled over the computer keyboard and you imagine you could wish the sugary, milky brew back into the coffee cup - where it had been just seconds before. But wishing won't work. Because, as mentioned, nature strives for chaos.

Scientists have coined the term entropy for this effect - a measure of disorder. In most cases, if the disorder increases, processes run spontaneously and the way back to the previously prevailing order is blocked. See the spilled coffee cup. Even thermal power plants, which generate a huge cloud of steam above their cooling tower from a neat pile of wood or a heap of hard coal, operate driven by entropy. Disorder increases dramatically in many combustion processes - and humans take advantage of this, tapping a bit of energy in the form of electricity from the ongoing process for their own purposes.

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