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Archive for the ‘chemistry’ category: Page 286

Aug 15, 2020

New catalyst efficiently turns carbon dioxide into useful fuels and chemicals

Posted by in categories: chemistry, energy, sustainability

As levels of atmospheric carbon dioxide continue to climb, scientists are looking for new ways of breaking down CO2 molecules to make useful carbon-based fuels, chemicals and other products. Now, a team of Brown University researchers has found a way to fine-tune a copper catalyst to produce complex hydrocarbons—known as C2-plus products—from CO2 with remarkable efficiency.

In a study published in Nature Communications, the researchers report a catalyst that can produce C2-plus compounds with up to 72% faradaic efficiency (a measure of how efficiently is used to convert carbon dioxide into chemical reaction products). That’s far better than the reported efficiencies of other catalysts for C2-plus reactions, the researchers say. And the preparation process can be scaled up to an industrial level fairly easily, which gives the new catalyst potential for use in large-scale CO2 recycling efforts.

“There had been reports in the literature of all kinds of different treatments for that could produce these C2-plus with a range of different efficiencies,” said Tayhas Palmore, the a professor of engineering at Brown who co-authored the paper with Ph.D. student Taehee Kim. “What Taehee did was a set of experiments to unravel what each of these treatment steps was actually doing to the catalyst in terms of reactivity, which pointed the way to optimizing a catalyst for these multi-carbon compounds.”

Aug 14, 2020

Exponential scaling of frictional forces in cells

Posted by in categories: biological, chemistry

AMOLF researchers have presented a theory that describes the friction between biological filaments that are crosslinked by proteins. Surprisingly, their theory predicts that the friction force scales highly nonlinearly with the number of crosslinkers. The authors believe that cells use this scaling not only to stabilize cellular structures, but also to control their size. The new findings are important for the understanding of the dynamics of cellular structures such as the mitotic spindle, which pulls chromosomes apart during cell division.

Motor proteins versus frictional forces

Many consist of long filaments that are crosslinked by motor proteins and non-motor proteins (see figure). These so-called cytoskeletal structures not only give cells their mechanical stability, but also enable them to crawl over surfaces and to pull chromosome apart during . Force generation is typically attributed to motor proteins, which, using chemical fuel, can move the filaments with respect to one another. However, these motor forces are opposed by frictional forces that are generated by passive, non–. These frictional forces are a central determinant of the mechanical properties of cytoskeletal structures, and they limit the speed and efficiency with which these structures are formed. Moreover, they can even be vital for their stability, because if the motor forces are not opposed by the forces generated by the passive crosslinkers, the structures can even fall apart.

Aug 13, 2020

Energy storing bricks for stationary PEDOT supercapacitors

Posted by in categories: chemistry, energy

Fired brick is a universal building material, produced by thousand-year-old technology, that throughout history has seldom served any other purpose. Here, we develop a scalable, cost-effective and versatile chemical synthesis using a fired brick to control oxidative radical polymerization and deposition of a nanofibrillar coating of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). A fired brick’s open microstructure, mechanical robustness and ~8 wt% α-Fe2O3 content afford an ideal substrate for developing electrochemical PEDOT electrodes and stationary supercapacitors that readily stack into modules. Five-minute epoxy serves as a waterproof case enabling the operation of our supercapacitors while submerged underwater and a gel electrolyte extends cycling stability to 10,000 cycles with ~90% capacitance retention.

Aug 13, 2020

Engineers manipulate color on the nanoscale, making it disappear

Posted by in categories: chemistry, nanotechnology, particle physics

Most of the time, a material’s color stems from its chemical properties. Different atoms and molecules absorb different wavelengths of light; the remaining wavelengths are the “intrinsic colors” that we perceive when they are reflected back to our eyes.

So-called “” works differently; it’s a property of physics, not chemistry. Microscopic patterns on some surfaces reflect light in such a way that different wavelengths collide and interfere with one another. For example, a peacock’s feathers are made of transparent protein fibers that have no intrinsic color themselves, yet we see shifting, iridescent blue, green and purple hues because of the nanoscale structures on their surfaces.

As we become more adept at manipulating structure at the smallest scales, however, these two types of color can combine in even more surprising ways. Penn Engineers have now developed a system of nanoscale semiconductor strips that uses structural color interactions to eliminate the strips’ intrinsic color entirely.

Aug 13, 2020

$212M Hydrogen Power Plant Project Complete

Posted by in categories: chemistry, energy, engineering

Energy solutions company Hanwha Energy has completed its $212m hydrogen fuel cell power plant, located at the Daesan Industrial Complex in Seosan, South Korea.

Built by Hanwha Engineering & Construction, the plant is thought to be the largest industrial hydrogen fuel cell power plant globally, and the first to only use hydrogen recycled from petrochemical manufacturing.

The recycled hydrogen is supplied by the Hanwha Total Petrochemical plant located within the same Daesan Industrial Complex. Hanwha Total Petrochemical pumps the recycled hydrogen into the new power plant via underground pipes and feeds it directly into the fuel cells.

Aug 12, 2020

Tesla Has Been Working On an RNA Bioreactor

Posted by in categories: biotech/medical, chemistry

Tesla and CureVac have collaborated on a patent for an RNA bioreactor.

Although there are no human vaccines made with RNA, the technology could break through on COVID-19 (coronavirus).

The bioreactor works by combining chemical agents in an egg-shaped magnetic mixer.

Continue reading “Tesla Has Been Working On an RNA Bioreactor” »

Aug 12, 2020

The Department of Energy Learned How to Turn Carbon Dioxide Into Liquid Fuel

Posted by in categories: chemistry, energy, sustainability

Researchers at Argonne National Laboratory say they’ve found a breakthrough way to recycle carbon dioxide into energy-rich ethanol fuel. The secret is an electrified catalyst made from copper and carbon, which the researchers say can be powered using low-cost off-peak or renewable energy. What results is a process that’s more than 90 percent effective, which they say is far higher than any similar existing process.

Northern Illinois University professor and participating Argonne researcher Tao Xu says the new catalyst isn’t just a single stop that can produce ethanol—it’s the first step down a possible long list of ways to turn carbon dioxide into other useful chemicals. Despite the obvious plenitude of carbon dioxide, recycling it effectively into new things has been hard because of how stable and chemically stubborn the molecules are.

Aug 11, 2020

Chernobyl Fungus Eats Nuclear Radiation Via Radiosynthesis

Posted by in categories: chemistry, nuclear energy, space

The earth’s atmosphere and magnetic field protect humans from harmful radiation. However, it is a known fact that astronauts are exposed to radiation levels that are 20-fold higher than those found on planet earth. NASA recently did an experiment on the International Space Station after realizing that a fungus growing near the Chernobyl site was thriving on nuclear radiation because of radiosynthesis. The fungus was using melanin to convert gamma radiation into chemical energy. Therefore, space scientists grew the fungus inside the ISS for a month and analyzed its ability to block radiation.

The experiment showed that the Chernobyl fungus, now identified as “Cladosporium sphaerospermum,” was able to block some of the incoming radiation. This finding has implications for future space missions. Scientists are thinking of shielding astronauts and space objects with a layer of this radiation-absorbing protective fungus. Meanwhile, let’s await further updates from NASA. Please share your thoughts with us in the comments section.

Aug 11, 2020

Discovery of massless electrons in phase-change materials provides next step for future electronics

Posted by in categories: chemistry, materials

Researchers have found electrons that behave as if they have no mass, called Dirac electrons, in a compound used in rewritable discs, such as CDs and DVDs. The discovery of ‘massless’ electrons in this phase-change material could lead to faster electronic devices.

The international team published their results on July 6 in ACS Nano, a journal of the American Chemical Society.

The compound, GeSb2Te4, is a phase-change material, meaning its atomic shifts from amorphous to crystalline under heat. Each structure has individual properties and is reversible, making the compound an ideal material to use in electronic devices where information can be written and rewritten several times.

Aug 11, 2020

Explosive Nuclear Astrophysics: New Method Developed to Determine Origin of Stardust in Meteorites

Posted by in categories: chemistry, physics, space

International team develops a new method to determine the origin of stardust in meteorites.

Analysis of meteorite content has been crucial in advancing our knowledge of the origin and evolution of our solar system. Some meteorites also contain grains of stardust. These grains predate the formation of our solar system and are now providing important insights into how the elements in the universe formed.

Working in collaboration with an international team, nuclear physicists at the U.S. Department of Energy’s (DOE’s) Argonne National Laboratory have made a key discovery related to the analysis of “presolar grains” found in some meteorites. This discovery has shed light on the nature of stellar explosions and the origin of chemical elements. It has also provided a new method for astronomical research.