Tag Archives: chemistry

Q-carbon: A new phase of carbon so hard it forms diamonds when melted

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Diamond, being the world’s hardest substance, has a range of uses in creating cutting and polishing tools across industries from mining to medicine. The challenge is that diamond is expensive to mine and to manufacture, requiring high temperatures and high pressures. But by mixing up the substrates and controlling the rate of cooling, Narayan and his team have discovered they can create tiny diamonds within the Q-carbon.

Source: Q-carbon: A new phase of carbon so hard it forms diamonds when melted

Computer chips made of wood promise greener electronics

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The researchers used a cellulose material for the substrate of the chip, which is the part that supports the active semiconductor layer. Taken from cellulose, a naturally abundant substance used to make paper, cellulose nanofibril (CNF) is a flexible, transparent and sturdy material with suitable electrical properties.

Source: Computer chips made of wood promise greener electronics

In a conventional chip, the support substrate is made of the same material as the active layer, but in the CNF chip, only the active layer is semiconductor material

Researchers design bionic leaf capable of converting sunlight into liquid fuel

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“We’re almost at a 1 percent efficiency rate of converting sunlight into isopropanol,” Nocera said. “There have been 2.6 billion years of evolution, and Pam and I working together a year and a half have already achieved the efficiency of photosynthesis.”

via Researchers design bionic leaf capable of converting sunlight into liquid fuel – Techie News.

Mayfield told CBS News that the exact same thing – turning electrons into biomass – has already been done many a times previously by using the same bacteria.

Mathematicians Solve The Topological Mystery Behind The “Brazuca” World Cup Football

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The take-home message from Yuan-Jia and Bih-Yaw’ work is that the Brazuca ball does have a fullerene that is its molecular analogue, just like its predecessors at all the world cups dating back to 1970

via Mathematicians Solve The Topological Mystery Behind The “Brazuca” World Cup Football  — The Physics arXiv Blog — Medium.

Startup Has a New Way to Make Rare Earths and Other Metals

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The ceramic material Powell showed me—which is made of zirconium oxide—replaces the carbon electrode and eliminates those emissions. Researchers have been trying to replace carbon for many years, but the molten salts have corroded the alternatives. The key advance for Infinium was developing alternative molten salts that don’t react with the zirconium oxide, so that it can last long enough to be practical.

via Startup Has a New Way to Make Rare Earths and Other Metals | MIT Technology Review.

Finding an alternative to carbon has long been the “dream” of the metals industry, says Donald Sadoway, a professor of materials science at MIT who is not involved with the company. “I believe [Infinium’s] technology is sound. It’s real,” he says. Whether the company succeeds “is all about the economics,” he says. “No one cares about the flow chart for the process. You care about the prices. If it produces a good metal at a lower cost, people will be interested.”

Preventing Heat From Going to Waste

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 Thermoelectrics are slabs of semiconductor with a strange and useful property: heating them on one side generates an electric voltage that can be used to drive a current and power devices. To obtain that voltage, thermoelectrics must be good electrical conductors but poor conductors of heat, which saps the effect. Unfortunately, because a material’s electrical and heat conductivity tend to go hand in hand, it has proven difficult to create materials that have high thermoelectric efficiency—a property scientists represent with the symbol ZT.

via Preventing Heat From Going to Waste | Science/AAAS | News.

The key to the ultralow thermal conductivity, Kanatzidis says, appears to be the pleated arrangement of tin and selenium atoms in the material, which looks like an accordion. The pattern seems to help the atoms flex when hit by heat-transmitting vibrations called phonons, thus dampening SbSe’s ability to conduct heat. The researchers report the results today in Nature.

Nanoscale optical switch breaks miniaturization barrier

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The ultrafast switch is made out of an artificial material engineered to have properties that are not found in nature. In this case, the “metamaterial” consists of nanoscale particles of vanadium dioxide (VO2) – a crystalline solid that can rapidly switch back and forth between an opaque, metallic phase and a transparent, semiconducting phase – which are deposited on a glass substrate and coated with a “nanomesh” of tiny gold nanoparticles.

The scientists report that bathing these gilded nanoparticles with brief pulses from an ultrafast laser generates hot electrons in the gold nanomesh that jump into the vanadium dioxide and cause it to undergo its phase change in a few trillionths of a second.

via Nanoscale optical switch breaks miniaturization barrier | Research News @ Vanderbilt | Vanderbilt University.

Startup Cuts Lithium-Ion Battery Costs

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So far, SolidEnergy has made small, hand-built battery cells, similar to what you would find in a cell phone, using equipment and experts at an A123 Systems lab near Boston. (A123 Systems went bankrupt last year, and was acquired by the Chinese company Wanxiang.) These experimental cells store 30 percent more energy than conventional lithium-ion batteries, but the company calculates that the approach could eventually lead to a 40 percent improvement.

via Startup Cuts Lithium-Ion Battery Costs | MIT Technology Review.

Scientists who took chemistry into cyberspace win Nobel Prize

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Chemical reactions occur at lightning speed as electrons jump between atomic nuclei, making it virtually impossible to map every separate step in chemical processes involving large molecules like proteins.

Powerful computer models, first developed by the three scientists in 1970s, offer a new window onto such reactions and have become a mainstay for researchers in thousands of academic and industrial laboratories around the world.

via Scientists who took chemistry into cyberspace win Nobel Prize – chicagotribune.com.