materialsscienceandengineering:
A tungsten rod with an oxidized surface and the filament of a tungsten light bulb on either side of the metal’s most stable crystal structure, body-centered cubic.
Sources: Tungsten, Structure
Tungsten is a pretty awesome metal.
materialsscienceandengineering:
Promising new cathode material to enhance battery life
Nowadays Li-ion batteries power a wide range of electronic devices: mobile phones, tablets, laptops. They became popular in 90s and subsequently ousted widespread nickel-metal hydride batteries.
However, Li-ion batteries suffer a number of disadvantages. For example, their capacity may drop when temperature falls below zero. The price is also inhibitory due to the use of expensive lithium-containing materials—for example, Li-ion batteries are responsible for about half of the cost of the electric Tesla Model S vehicle. However, Li-ion batteries are compact, easy to use and high capacity, offering long performance from relatively small batteries.
One limiting factor of Li-ion batteries is the cathode, as capacity limits for most cathode materials have been reached. Hence, scientists and engineers are actively searching for new cathode materials capable of recharging completely within minutes, operating under high current densities, and storing more energy.
One of the most promising candidates for next-generation cathode materials is fluoride-phosphates of transition metals.
The work, directed by Prof. Evgeny Antipov, was conducted by a team of MSU research scientists together with their Russian and Belgian colleagues. It was devoted to the creation of a new, high-power cathode material based on a fluoride-phosphate of vanadium and potassium for Li-ion batteries. The results were published in Chemistry of Materials.
Yay, battery chemistry!
materialsscienceandengineering:
Scientists achieve perfect efficiency for water-splitting half-reaction
Splitting water is a two-step process, and in a new study, researchers have performed one of these steps (reduction) with 100% efficiency. The results shatter the previous record of 60% for hydrogen production with visible light, and emphasize that future research should focus on the other step (oxidation) in order to realize practical overall water splitting. The main application of splitting water into its components of oxygen and hydrogen is that the hydrogen can then be used to deliver energy to fuel cells for powering vehicles and electronic devices.
The researchers, Philip Kalisman, Yifat Nakibli, and Lilac Amirav at the Technion-Israel Institute of Technology in Haifa, Israel, have published a paper on the perfect efficiency for the water reduction half-reaction in a recent issue of Nano Letters.
“I strongly believe that the search for clean and renewable energy sources is crucial,” Amirav told Phys.org. “With the looming energy crisis on one hand, and environmental aspects, mainly global warming, on the other, I think this is our duty to try and amend the problem for the next generation.
Perfect efficiency? Crazy.
Brace yourselves ‘cause this element can get a little SAVAGE. For today’s edition of METAL MONDAY we examine a transition metal that’s hazardous to humans, but plays an important role in some solar panels: Cadmium (Cd).
- Certain forms and concentrations of cadmium render the metal toxic, but its still been widely used throughout history, even in medical applications. A 1907 pharmaceutical record notes cadmium iodide was used to treat “enlarged joints, scrofulous glands, and chilblains.”
- The metal has also been used as a coating for iron and steel to prevent corrosion and as a yellow pigment. As an understanding of its toxicity developed, the metal was shifted into more docile applications – like batteries.
- The compound cadmium telluride (see second image above) is a component in certain solar cells. Its found limited use, however, due to concerns about toxicity. Still, advocates of cadmium-powered technology say the metal will be mined anyway (often as a byproduct of zinc refining) and argue its use in solar panels is preferable to disposal as hazardous waste.
- It’s named after the Greek mythological character Cadmus, one of the first Greek heroes and the legendary founder of the city of Thebes.
(Image Credit: Wikimedia Commons / Source: The University of Nottingham, CDC, Wikimedia Commons, )
More than you ever wanted to know about Cadmium.
Literally watching a magnetic stir bar do its thing in lab…
These are literally the worst chem labs…
materialsscienceandengineering:
Carbon dioxide captured from air can be directly converted into methanol fuel
For the first time, researchers have demonstrated that CO2 captured from the air can be directly converted into methanol (CH3OH) using a homogeneous catalyst. The benefits are two-fold: The process removes harmful CO2 from the atmosphere, and the methanol can be used as an alternative fuel to gasoline. The work represents an important step that could one day lead to a future “methanol economy,” in which fuel and energy storage are primarily based on methanol.
The study was led by G. K. Surya Prakash, a chemistry professor at the University of Southern California, along with the Nobel laureate George A. Olah, a distinguished professor at the University of Southern California. The researchers have published their paper on the CO2-to-methanol conversion process in a recent issue of the Journal of the American Chemical Society.
“Direct CO2 capture and conversion to methanol using molecular hydrogen in the same pot was never achieved before. We have now done it!” Prakash told Phys.org.
Over the past several years, chemists have been investigating various ways of recycling CO2 into useful products. For example, treating CO2 with hydrogen gas (H2) can produce methanol, methane (CH4), or formic acid (HCOOH). Among these products, methanol is especially attractive because of its use as an alternative fuel, in fuel cells, and for hydrogen storage.
Cool!
Buckminsterfullerene
Also called buckyball, it is a spherical fullerene molecule with the formula C60. It has a cage-like fused-ring structure (truncated icosahedron) which resembles a soccer ball, made of twenty hexagons and twelve pentagons, with a carbon atom at each vertex of each polygon and a bond along each polygon edge.
- Buckyballs may be used to trap free radicals generated during an allergic reaction and block the inflammation that results from an allergic reaction.
- The antioxidant properties of buckyballs may be able to fight the deterioration of motor function due to multiple sclerosis.
- Combining buckyballs, nanotubes, and polymers to produce inexpensive solar cells that can be formed by simply painting a surface.
- Buckyballs may be used to store hydrogen, possibly as a fuel tank for fuel cell powered cars.
- Buckyballs may be able to reduce the growth of bacteria in pipes and membranes in water systems.
- Researchers are attempting to modify buckyballs to fit the section of the HIV molecule that binds to proteins, possibly inhibiting the spread of the virus.
- Making bullet proof vests with inorganic (tungsten disulfide) buckyballs.
This is such a weird structure…
We’ve all seen the Febreze air fresheners, which employ a derivative of corn starch to trap invisible air pollutants in the home and remove unwanted odors. A team of Cornell researchers has used the same material found in Febreze, cyclodextrin, to develop a technique that could revolutionize the …
Febreeze put to use doing something besides covering up unpleasant smells. Nice.
What happened in chemistry in 2015? Here’s a round-up of some of the most interesting stories!
Science!
A small amount of Cesium metal. Caesium or cesium is a chemical element with symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C (82 °F), which makes it liquid at or near room temperature (as seen from the gif).
It is highly reactive and very pyrophoric, it ignites spontaneously in air and reacts explosively with water. Because of it’s high reactivity caesium can be stored in vacuum-sealed borosilicate glass ampoules.
Interesting fact: In 1860, Robert Bunsen and Gustav Kirchhoff discovered caesium in the mineral water from Dürkheim, Germany. Due to the bright blue lines in its emission spectrum, they chose a name derived from the Latin word caesius, meaning sky-blue. Caesium was the first element to be discovered spectroscopically, only one year after the invention of the spectroscope by Bunsen and Kirchhoff.
This is a pretty cool element.
materialsscienceandengineering:
Caution: Weird material shrinks when warm
Most materials swell when they warm, but some do the opposite; quantum effects could explain why
Most materials swell when they warm, and shrink when they cool. But UConn physicist Jason Hancock has been investigating a substance that responds in reverse: it shrinks when it warms.
Although thermal expansion, and the cracking and warping that often result, are an everyday occurrence – in buildings, bridges, electronics, and almost anything else exposed to wide temperature swings – physicists have trouble explaining why solids behave that way.
Research by Hancock and his colleagues into scandium trifluoride, a material that has negative thermal expansion, published 1 October in Physical Review B, may lead to a better understanding of why materials change volume with temperature at all, with potential applications such as more durable electronics.
What.
materialsscienceandengineering:
A vial of glowing ultrapure xenon.
Beautiful.
Then open your eyes and see what I present to you: The Atomic Force Microscope *drumroll*
What does it do? It takes pictures of Molecules.
No, really. It does.
( Source )
This is an actual photograph of Pentacene.
You can see the atomic bonds. Like in a structural formula! It’s absolutely astonishing.
But wait, there is more!
Because this technology can do even better. The middle pictures are the molecules in the bottom row before and after a reaction that transforms their structure.
( Source )
WE CAN WATCH CHEMISTRY AS IT HAPPENS!
I can’t even think of the implications of this technology. All the expenditures of finding out how a molecule is formed and now we - in a limited way - can just look at it. Amazing.
(via talontwo)
This is incredible.
