Chemical Science

New concepts emerge for generating clean, inexpensive fuel from water

noreply@blogger.com (Anonymous) — Wed, 25 Nov 2015 04:25:00 +0000

An inexpensive method for generating clean fuel is the modern-day equivalent of the philosopher’s stone. One compelling idea is to use solar energy to split water into its constituent hydrogen and oxygen and then harvest the hydrogen for use as fuel. But splitting water efficiently turns out to be not so easy. - Read more here

Splitting water into hydrogen provides a means of harvesting the hydrogen for fuel. This image depicts the water-splitting process in a light-sensitive electrode material (BiVO4), which UChicago and University of Wisconsin researchers investigated in an experimental and computational study.

Illustration by Peter Allen, Credit: University of Chicago

BACK TO BLOGGY

noreply@blogger.com (Anonymous) — Tue, 24 Nov 2015 12:33:00 +0000

Coming back to blogging... :)

Molecular footballs could revolutionize your next World Cup experience

noreply@blogger.com (Anonymous) — Tue, 24 Jun 2014 03:52:00 +0000

A new way to assemble individual molecules could revolutionize the creation of novel materials with numerous potential applications, including emerging technologies such as flexible TVs. The results of this ground-breaking research are published on 22 June in the prestigious journal Nature Chemistry.

Read more here...

Evolution of a bimetallic nanocatalyst

noreply@blogger.com (Anonymous) — Sat, 07 Jun 2014 05:14:00 +0000

Atomic-scale snapshots of a bimetallic nanoparticle catalyst in action have provided insights that could help improve the industrial process by which fuels and chemicals are synthesized from natural gas, coal or plant biomass. A multi-national lab collaboration led by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has taken the most detailed look ever at the evolution of platinum/cobalt bimetallic nanoparticles during reactions in oxygen and hydrogen gases.

TEM image of platinum/cobalt bimetallic nanoparticle catalyst in action shows that during the oxidation reaction, cobalt atoms migrate to the surface of the particle, forming a cobalt oxide epitaxial film, like water on oil.

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New fluorescent hybrid material changes color according to direction of light

noreply@blogger.com (Anonymous) — Thu, 01 May 2014 03:32:00 +0000

The UPV/EHU's Molecular Spectroscopy Group, in collaboration with the Institute of Catalysis and Petroleum Chemistry of the CSIC (Spanish National Research Council), has developed a highly fluorescent hybrid material that changes colour depending on the polarisation of the light that it is illuminated by.

The research has been published in ACS Photonics, the new journal devoted exclusively to Photonics published by the American Chemical Society.

The aim with respect to hybrid materials with one organic component and another inorganic one is to combine the best attributes of each one into a single system.

Labs across the world are working to develop new hybrid materials for technological applications in nanotechnologies, in particular, and these materials are already being used in lightweight materials for cars, sports equipment, in biomimetic materials, like prostheses, etc.

Read more...

Left: CIE system or chromaticity diagram to characterise the colours.
Above right: green emission obtained using linearly polarised light along the channels. Below right: blue emission obtained using light linearly perpendicular to the channels. NB: the arrows indicate the direction in the polarisation of the light used.

Steering Chemical Reactions with Laser Pulses

noreply@blogger.com (Anonymous) — Thu, 24 Apr 2014 06:13:00 +0000

Usually, chemical reactions just take their course, much like a ball rolling downhill.

However, it is also possible to deliberately control chemical reactions: at the Vienna University of Technology, molecules are hit with femtosecond laser pulses, changing the distribution of electrons in the molecule.

This interaction is so short that at first it does not have any discernable influence on the atomic nuclei, which have much more mass than the electrons. However, the disturbance of the electron distribution can still initiate chemical processes and eventually separate the nuclei from each other.

The properties of the laser pulse determine which chemical final products are created.

Read more here...

Short laser pulses interacting with ethylene

PNNL: News - Halving hydrogen

noreply@blogger.com (Anonymous) — Thu, 24 Apr 2014 06:09:00 +0000

PNNL: News - Halving hydrogen

Like a hungry diner ripping open a dinner roll, a fuel cell catalyst that converts hydrogen into electricity must tear open a hydrogen molecule.

Now researchers have captured a view of such a catalyst holding onto the two halves of its hydrogen feast. The view confirms previous hypotheses and provides insight into how to make the catalyst work better for alternative energy uses.

This study is the first time scientists have shown precisely where the hydrogen halves end up in the structure of a molecular catalyst that breaks down hydrogen, the team reported online April 22 in Angewandte Chemie International Edition.

The design of this catalyst was inspired by the innards of a natural protein called a hydrogenase enzyme.

Read more here...

Neutron crystallography shows this iron catalyst gripping two hydrogen atoms (red spheres). This arrangement allows an unusual dihydrogen bond to form between the hydrogen atoms (red dots).

Inspired by a music box, Stanford bioengineer creates $5 chemistry set

noreply@blogger.com (Anonymous) — Sun, 13 Apr 2014 12:53:00 +0000

When Manu Prakash was young he had a thing about flames. He's not encouraging all kids to follow his fiery lead – he did burn one hand pretty badly – but he thinks kids should explore more when it comes to learning about science. That's the idea behind his programmable, toy-like device that won a competition to "reimagine the chemistry set for the 21st century."

Read more here...

Fighting cancer with lasers and nanoballoons that pop

noreply@blogger.com (Anonymous) — Tue, 08 Apr 2014 10:36:00 +0000

Chemotherapeutic drugs excel at fighting cancer, but they’re not so efficient at getting where they need to go.

They often interact with blood, bone marrow and other healthy bodily systems. This dilutes the drugs and causes unwanted side effects.

Now, researchers are developing a better delivery method by encapsulating the drugs in nanoballoons – which are tiny modified liposomes that, upon being struck by a red laser, pop open and deliver concentrated doses of medicine.

Read more here...

The image shows a nanoballoon before (left) and after (right) being hit by a red laser. The laser causes the balloon to pop open and release the anti-cancer drugs directly at a tumor. Credit: Jonathan Lovell

Making the Most of Carbon Nanotube-Liquid Crystal Combos

noreply@blogger.com (Anonymous) — Fri, 04 Apr 2014 14:13:00 +0000

Dispersions of carbon nanotubes with liquid crystals have attracted much interest because they pave the way for creating new materials with added functionalities.

Now, a study published in EPJ E by Marina Yakemseva and colleagues at the Nanomaterials Research Institute in Ivanovo, Russia, focuses on the influence of temperature and nanotube concentration on the physical properties of such combined materials.

These findings could have implications for optimising these combinations for non-display applications, such as sensors or externally stimulated switches, and novel materials that are responsive to electric, magnetic, mechanical or even optical fields.

Read more here...

Dispersed multi-wall carbon nanotubes on a glass surface. Credit: Yakemseva et al.

How Electrodes Charge and Discharge

noreply@blogger.com (Anonymous) — Fri, 04 Apr 2014 14:10:00 +0000

The electrochemical reactions inside the porous electrodes of batteries and fuel cells have been described by theorists, but never measured directly.

Now, a team at MIT has figured out a way to measure the fundamental charge transfer rate — finding some significant surprises.

The study found that the Butler-Volmer (BV) equation, usually used to describe reaction rates in electrodes, is inaccurate, especially at higher voltage levels.

Instead, a different approach, called Marcus-Hush-Chidsey charge-transfer theory, provides more realistic results — revealing that the limiting step of these reactions is not what had been thought.

Read more here...

This illustration shows a battery electrode made of lithium iron phosphate (left side of image) coated with carbon, and in contact with an electrolyte material. As the battery is discharged, lithium ions (shown in purple) jump across the coating and insert themselves into the crystal structure, while electrons (shown as circles with minus signs) in the carbon-coating tunnel into the material and attach to iron ions (shown in red). (Phosphate groups are left out of this diagram for clarity.) Illustration courtesy of Peng Bai and Martin Bazant

Energy Breakthrough Uses Sun to Create Solar Energy Materials

noreply@blogger.com (Anonymous) — Fri, 04 Apr 2014 14:07:00 +0000

In a recent advance in solar energy, researchers have discovered a way to tap the sun not only as a source of power, but also to directly produce the solar energy materials that make this possible.

This breakthrough by chemical engineers at Oregon State University could soon reduce the cost of solar energy, speed production processes, use environmentally benign materials, and make the sun almost a “one-stop shop” that produces both the materials for solar devices and the eternal energy to power them.

Read more here...

Revolutionary Solar Cells Double as Lasers

noreply@blogger.com (Anonymous) — Mon, 31 Mar 2014 13:14:00 +0000

Revolutionary solar cells double as lasers

Commercial silicon-based solar cells - such as those seen on the roofs of houses across the country - operate at about 20% efficiency for converting the Sun’s rays into electrical energy. It’s taken over 20 years to achieve that rate of efficiency.

A relatively new type of solar cell based on a perovskite material - named for scientist Lev Perovski, who first discovered materials with this structure in the Ural Mountains in the 19th century - was recently pioneered by an Oxford research team led by Professor Henry Snaith.

Read more here...

Robotic Arm Probes Chemistry of 3-D Objects by Mass Spectrometry

noreply@blogger.com (Anonymous) — Mon, 31 Mar 2014 13:09:00 +0000

Robotic Arm Probes Chemistry of 3-D Objects by Mass Spectrometry

When life on Earth was first getting started, simple molecules bonded together into the precursors of modern genetic material.

A catalyst would have been needed, but enzymes had not yet evolved.

One theory is that the catalytic minerals on a meteorite’s surface could have jump-started life’s first chemical reactions.

But scientists need a way to directly analyze these rough, irregularly shaped surfaces.

A new robotic system at Georgia Tech’s Center for Chemical Evolution could soon let scientists better simulate and analyze the chemical reactions of early Earth on the surface of real rocks to further test this theory.

Nanotube Coating Helps Shrink Mass Spectrometers

noreply@blogger.com (Anonymous) — Mon, 31 Mar 2014 13:08:00 +0000

Nanotube coating helps shrink mass spectrometers

Nanotechnology is advancing tools likened to Star Trek's "tricorder" that perform on-the-spot chemical analysis for a range of applications including medical testing, explosives detection and food safety.

Researchers found that when paper used to collect a sample was coated with carbon nanotubes, the voltage required was 1,000 times reduced, the signal was sharpened and the equipment was able to capture far more delicate molecules.

A carbon nanotube-coated paper triangle placed on an ionization source charged by a small battery is held in front of a mass spectrometer. Researchers at Purdue University and the Indian Institute of Technology Madras studied the use of carbon nanotubes to advance ambient ionization techniques. (Purdue University photo/Courtesy of Thalappil Pradeep)

WORLD WATER DAY

noreply@blogger.com (Anonymous) — Sat, 22 Mar 2014 13:56:00 +0000

Water and energy are closely interlinked and interdependent. Energy generation and transmission requires utilization of water resources, particularly for hydroelectric, nuclear, and thermal energy sources. Conversely, about 8% of the global energy generation is used for pumping, treating and transporting water to various consumers.
Credit: http://www.unwater.org

New Technique Makes LEDs Brighter, More Resilient

noreply@blogger.com (Anonymous) — Sat, 22 Mar 2014 13:46:00 +0000

New Technique Makes LEDs Brighter, More Resilient

“By coating polar GaN with a self-assembling layer of phosphonic groups, we were able to increase luminescence without increasing energy input,” says Stewart Wilkins, a Ph.D. student at NC State and lead author of a paper describing the work. “The phosphonic groups also improve stability, making the GaN less likely to degrade in solution.

Scientists open a new window into quantum physics with superconductivity in LEDs

noreply@blogger.com (Anonymous) — Wed, 19 Mar 2014 13:18:00 +0000

A team of University of Toronto physicists led by Alex Hayat has proposed a novel and efficient way to leverage the strange quantum physics phenomenon known as entanglement.

The approach would involve combining light-emitting diodes (LEDs) with a superconductor to generate entangled photons and could open up a rich spectrum of new physics as well as devices for quantum technologies, including quantum computers and quantum communication.

Read more here...

Toward ‘Vanishing’ Electronics and Unlocking Nanomaterials’ Power Potential

noreply@blogger.com (Anonymous) — Wed, 19 Mar 2014 13:14:00 +0000

Brain sensors and electronic tags that dissolve. Boosting the potential of renewable energy sources. These are examples of the latest research from two pioneering scientists selected as this year’s Kavli lecturers at the 247^th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society.

Read more here...

Biodegradable materials from Rogers’ lab could one day transform electronics for consumer and medical devices, as illustrated here in a dissolvable RFID tag prototype.

Credit: John Rogers

High-tech Materials Purify Water with Sunlight

noreply@blogger.com (Anonymous) — Mon, 17 Mar 2014 04:13:00 +0000

Sunlight plus a common titanium pigment might be the secret recipe for ridding pharmaceuticals, pesticides and other potentially harmful pollutants from drinking water.

Scientists combined several high-tech components to make an easy-to-use water purifier that could work with the world’s most basic form of energy, sunlight, in a boon for water purification in rural areas or developing countries.

Read more here...

Graphene (above), along with sunlight and titanium dioxide, can purify drinking water.

Credit: Tyndall National Institute

Recovering Metals and Minerals from Waste

noreply@blogger.com (Anonymous) — Mon, 17 Mar 2014 04:09:00 +0000

Scarcity of clean water is one of the most serious global challenges. In its spearhead programme, VTT Technical Research Centre of Finland developed energy-efficient methods for reuse of water in industrial processes and means for recovering valuable minerals and materials from waste for recycling.

Rapid tools were also developed for identification of environmental pollutants.

When water and wastewater systems are developed in a comprehensive manner, it is possible to recover valuable metals and other materials and secure availability of clean water.

Cleaning and treatment processes can also be linked to energy production, and the processes and urban structures designed in such a manner that wastewater treatment does not consume energy or cause extra costs.

Read more here...

Credit: Prof. Mona Arnold, et al.

Researchers Describe Oxygen’s Different Shapes

noreply@blogger.com (Anonymous) — Sat, 15 Mar 2014 04:05:00 +0000

Oxygen-16, one of the key elements of life on earth, is produced by a series of reactions inside of red giant stars.

Now a team of physicists, including one from North Carolina State University, has revealed how the element’s nuclear shape changes depending on its state, even though other attributes such as spin and parity don’t appear to differ.

Their findings may shed light on how oxygen is produced.

Carbon and oxygen are formed when helium burns inside of red giant stars.

Carbon-12 forms when three helium-4 nuclei combine in a very specific way (called the triple alpha process), and oxygen-16 is the combination of a carbon-12 and another helium-4 nucleus.

Read more here...

The shape of oxygen-16 in its ground and first excited state. Credit: Dean Lee et al.

Scientists Discover a Better Way to Make Unnatural Amino Acids

noreply@blogger.com (Anonymous) — Sat, 15 Mar 2014 04:01:00 +0000

Chemists at The Scripps Research Institute (TSRI) have devised a greatly improved technique for making amino acids not found in nature.

These “unnatural” amino acids traditionally have been very difficult to synthesize, but are sought after by the pharmaceutical industry for their potential medical uses.

“This new technique offers a very quick way to prepare unnatural amino acids, many of which are drug candidates or building blocks for peptide drugs,” said Jin-Quan Yu, a professor in TSRI’s Department of Chemistry.

Read more here...

Four new human-made ozone depleting gases found in the atmosphere

noreply@blogger.com (Anonymous) — Tue, 11 Mar 2014 13:31:00 +0000

Scientists at the University of East Anglia have identified four new man-made gases in the atmosphere – all of which are contributing to the destruction of the ozone layer.

New research published today in the journal Nature Geoscience reveals that more than 74,000 tonnes of three new chlorofluorocarbons (CFCs) and one new hydrochlorofluorocarbon (HCFC) have been released into the atmosphere.

Read more here...

Newly Discovered Catalyst Could Lead to the Low-Cost, Clean Production of Methanol

noreply@blogger.com (Anonymous) — Wed, 05 Mar 2014 16:05:00 +0000

An international research team has discovered a potentially clean, low-cost way to convert carbon dioxide into methanol, a key ingredient in the production of plastics, adhesives and solvents, and a promising fuel for transportation.

Scientists from Stanford University, SLAC National Accelerator Laboratory and the Technical University of Denmark combined theory and experimentation to identify a new nickel-gallium catalyst that converts hydrogen and carbon dioxide into methanol with fewer side-products than the conventional catalyst. The results are published in the March 2 online edition of the journal Nature Chemistry.

Read more...

Artist's rendering of the nickel-gallium active site, which synthesizes hydrogen and carbon dioxide into methanol. Nickel atoms are light grey, gallium atoms are dark grey, and oxygen atoms are red. (Credit: Jens Hummelshoj/SLAC)