Scientists left baffled

as the official kilo loses weight

January 24, 2011 – 10:36AM

A computer-generated image of the international prototype kilogram, which is kept in a vault at the International Bureau of Weights and Measures near Paris.

Scientists say they are moving closer to coming up with a non-physical definition of the kilo after discovering the metal artefact used as the international standard had shed a fraction of its weight.

Researchers caution there is still some way to go before their mission is complete, but if successful it would lead to the end of the useful life of the last manufactured object on which fundamental units of measure depend.

At the moment, the international standard for the kilo is a chunk of metal, under triple lock-and-key in France since 1889.

But scientists became concerned about the cylinder of platinum and iridium housed at the International Bureau of Weights and Measures (BIPM) in Sevres, near Paris, after discovering it had mysteriously lost a minute amount of weight.

Experts at the institute revealed in 2007 that the metal chunk is 50 micrograms lighter than the average of several dozen copies, meaning it had lost the equivalent of a small grain of sand.

They are now searching for a non-physical way of defining the kilo, which would bring it in line with the six other base units that make up the International System of Units

Sourced & published by Henry Sapiecha

Ultra-Simple Method for Creating

Nanoscale Gold Coatings Developed

Researchers at Rensselaer have developed a new, ultra-simple method for making layers of gold that measure only billionths of a meter thick. As seen in the research image, drops of gold-infused toluene applied to a surface evaporate within a few minutes and leave behind a uniform layer of nanoscale gold. The process requires no sophisticated equipment, works on nearly any surface, takes only 10 minutes, and could have important implications for nanoelectronics and semiconductor manufacturing. (Credit: Image courtesy of Rensselaer Polytechnic Institute)

Gold plated porche.Munich show.

Science (June 21, 2010) — Researchers at Rensselaer Polytechnic Institute have developed a new, ultra-simple method for making layers of gold that measure only billionths of a meter thick. The process, which requires no sophisticated equipment and works on nearly any surface including silicon wafers, could have important implications for nanoelectronics and semiconductor manufacturing.

Sang-Kee Eah, assistant professor in the Department of Physics, Applied Physics, and Astronomy at Rensselaer, and graduate student Matthew N. Martin infused liquid toluene — a common industrial solvent — with gold nanoparticles. The nanoparticles form a flat, closely packed layer of gold on the surface of the liquid where it meets air. By putting a droplet of this gold-infused liquid on a surface, and waiting for the toluene to evaporate, the researchers were able to successfully coat many different surfaces — including a 3-inch silicon wafer — with a monolayer of gold nanoparticles.

“There has been tremendous progress in recent years in the chemical syntheses of colloidal nanoparticles. However, fabricating a monolayer film of nanoparticles that is spatially uniform at all length scales — from nanometers to millimeters — still proves to be quite a challenge,” Eah said. “We hope our new ultra-simple method for creating monolayers will inspire the imagination of other scientists and engineers for ever-widening applications of gold nanoparticles.”

Results of the study, titled “Charged gold nanoparticles in non-polar solvents: 10-min synthesis and 2-D self-assembly,” were published recently in the journal Langmuir.

Whereas other synthesis methods take several hours, this new method chemically synthesizes gold nanoparticles in only 10 minutes without the need for any post-synthesis cleaning, Eah said. In addition, gold nanoparticles created this way have the special property of being charged on non-polar solvents for 2-D self-assembly.

Previously, the 2-D self-assembly of gold nanoparticles in a toluene droplet was reported with excess ligands, which slows down and complicates the self-assembly process. This required the non-volatile excess ligands to be removed in a vacuum. In contrast, Eah’s new method ensures that gold nanoparticles float to the surface of the toluene drop in less than one second, without the need for a vacuum. It then takes only a few minutes for the toluene droplet to evaporate and leave behind the gold monoloayer.

“The extension of this droplet 2-D self-assembly method to other kinds of nanoparticles, such as magnetic and semiconducting particles, is challenging but holds much potential,” Eah said. “Monolayer films of magnetic nanoparticles, for instance, are important for magnetic data storage applications. Our new method may be able to help inform new and exciting applications.”

Co-authors on the paper are former Rensselaer undergraduate researchers James I. Basham ’07, who is now a graduate student at Pennsylvania State University, and Paul Chando ’09, who will begin graduate study in the fall at the City College of New York.

The research project was supported by Rensselaer, the Rensselaer Summer Undergraduate Research Program, the National Science Foundation (NSF) Research Experiences for Undergraduates, and the NSF’s East Asia and Pacific Summer Institutes and Japan Society for the Promotion of Science.

Watch a video demonstration of this new fabrication process at: http://www.youtube.com/watch?v=nqkwM9o1s-w

Sourced & published by Henry Sapiecha

EcoWire™: A True Engineering Breakthrough
Tough wire doesn’t have to be bulky or hard to recycle. Innovative EcoWire combines increased performance with a minimized environmental impact. EcoWire’s unique mPPE insulation is inherently lighter, tougher, and more durable than PVC. Plus, it contains no halogens and meets WEEE requirements.

More Information

Sourced and published by Henry Sapiecha 5th June 2010

Renewable Energy:

Inexpensive Metal Catalyst

Can Effectively Generate

Hydrogen from Water

Science (May 1, 2010) — Hydrogen would command a key role in future renewable energy technologies, experts agree, if a relatively cheap, efficient and carbon-neutral means of producing it can be developed. An important step towards this elusive goal has been taken by a team of researchers with the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley. The team has discovered an inexpensive metal catalyst that can effectively generate hydrogen gas from water.

“Our new proton reduction catalyst is based on a molybdenum-oxo metal complex that is about 70 times cheaper than platinum, today’s most widely used metal catalyst for splitting the water molecule,” said Hemamala Karunadasa, one of the co-discoverers of this complex. “In addition, our catalyst does not require organic additives, and can operate in neutral water, even if it is dirty, and can operate in sea water, the most abundant source of hydrogen on earth and a natural electrolyte. These qualities make our catalyst ideal for renewable energy and sustainable chemistry.”

Karunadasa holds joint appointments with Berkeley Lab’s Chemical Sciences Division and UC Berkeley’s Chemistry Department. She is the lead author of a paper describing this work that appears in the April 29, 2010 issue of the journal Nature, titled “A molecular molybdenum-oxo catalyst for generating hydrogen from water.” Co-authors of this paper were Christopher Chang and Jeffrey Long, who also hold joint appointments with Berkeley Lab and UC Berkeley. Chang, in addition, is also an investigator with the Howard Hughes Medical Institute (HHMI).

Hydrogen gas, whether combusted or used in fuel cells to generate electricity, emits only water vapor as an exhaust product, which is why this nation would already be rolling towards a hydrogen economy if only there were hydrogen wells to tap. However, hydrogen gas does not occur naturally and has to be produced. Most of the hydrogen gas in the United States today comes from natural gas, a fossil fuel. While inexpensive, this technique adds huge volumes of carbon emissions to the atmosphere. Hydrogen can also be produced through the electrolysis of water — using electricity to split molecules of water into molecules of hydrogen and oxygen. This is an environmentally clean and sustainable method of production — especially if the electricity is generated via a renewable technology such as solar or wind — but requires a water-splitting catalyst.

Nature has developed extremely efficient water-splitting enzymes — called hydrogenases — for use by plants during photosynthesis, however, these enzymes are highly unstable and easily deactivated when removed from their native environment. Human activities demand a stable metal catalyst that can operate under non-biological settings.

Metal catalysts are commercially available, but they are low valence precious metals whose high costs make their widespread use prohibitive. For example, platinum, the best of them, costs some $2,000 an ounce.

“The basic scientific challenge has been to create earth-abundant molecular systems that produce hydrogen from water with high catalytic activity and stability,” Chang says. “We believe our discovery of a molecular molybdenum-oxo catalyst for generating hydrogen from water without the use of additional acids or organic co-solvents establishes a new chemical paradigm for creating reduction catalysts that are highly active and robust in aqueous media.”

The molybdenum-oxo complex that Karunadasa, Chang and Long discovered is a high valence metal with the chemical name of (PY5Me2)Mo-oxo. In their studies, the research team found that this complex catalyzes the generation of hydrogen from neutral buffered water or even sea water with a turnover frequency of 2.4 moles of hydrogen per mole of catalyst per second.

Long says, “This metal-oxo complex represents a distinct molecular motif for reduction catalysis that has high activity and stability in water. We are now focused on modifying the PY5Me ligand portion of the complex and investigating other metal complexes based on similar ligand platforms to further facilitate electrical charge-driven as well as light-driven catalytic processes. Our particular emphasis is on chemistry relevant to sustainable energy cycles.”

This research was supported in part by the DOE Office of Science through Berkeley Lab’s Helios Solar Energy Research Center, and in part by a grant from the National science Foundation.

Sourced and published by Henry Sapiecha 2nd May 2010

Metal Conductive Rubber

Chemists Create Self-assembling

Hard than diamonds??

Although diamond is currently the undisputed champion of ultrahard materials, research teams around the world are engaged in a battle to find a new contender to topple it from its place; one which is cheaper, more durable, and more easily produced. Once such team, lead by Professor Richard Kaner of UCLA, have targeted transition metal borides as their diamond-killer of choice. Ultrahard materials are useful in many industrial applications, as, for example, abrasives, cutting tools, and coatings. But diamond isn’t always the best tool for the job; the chemical reaction between carbon and iron means that it isn’t suitable for use with ferrous materials, and the high temperature and pressure necessary to produce synthetic diamond can make the manufacturing process prohibitively expensive. In contrast, the materials considered by Prof. Kaner, such as rhenium diboride and tungsten tetraboride, have comparable or greater hardness and stress resistance, but can be potentially be produced at ambient pressure and can be used in a great variety of chemical environments.

Sourced and published by Henry Sapiecha 3rd Nov 2009