Lab-grown Diamonds

This shiny, sparkly diamond was made inside a laboratory – but it has the same chemical makeup as its counterpart found deep inside the earth.

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All the composition is exactly the same. It is a real diamond. What we’ve done is we’ve just taken what’s happened in nature and just put it in a lab,” said  Kelly Good, Director of Marketing of Pure Grown Diamonds.

Essentially, all diamonds are carbon. And inside a laboratory, scientists are using a method called microwave plasma chemical vapour deposition to grow the stones from a diamond seed. They do it by creating a plasma ball made of hydrogen inside a growth chamber. Methane, which is a carbon source, is added. The carbon mix rains down on the diamond seeds, layer by layer, creating a large, rough diamond that is cut and polished. The process takes about 10 to 12 weeks. Marketers tout the lab-grown diamonds as an eco-friendly, conflict-free alternative to mined diamonds. “Our consumer is millennials, anybody who is getting engaged are really buying the lab-grown diamonds. They also like the fact of the environmental aspect of it. That it’s grown in a greenhouse. There is less soil being moved. We have a less carbon footprint,” explains Kelly Good.

While similar in appearance, there are differences. David Weinstein, Executive Director of the International  Gemological Institute (New York), comments: “I have a crystal, a diamond and I’m looking at it and I see a peridot crystal, a green peridot crystal, I know right away, this wasn’t created in a machine. So the inclusions can really be very telling as to what the origins of the material is. And that’s what our gemologists look for.”
While lab-grown gems have been around for decades, but it’s only recently that the science and technology have made it possible to grow large, gem quality stones. And according to a report by Morgan Stanley, the lab-grown diamond market could grow by about 15 percent by the year 2020.

Source: http://www.reuters.com/

Semiconductors As Thin As An Atom

A two-dimensional material developed by physicist Prof. Dr. Axel Enders (Bayreuth University  in Germany) together with international partners could revolutionize electronicsSemiconductors that are as thin as an atom are no longer the stuff of .  Thanks to its semiconductor properties, this material could be much better suited for high tech applications than graphene, the discovery of which in 2004 was celebrated worldwide as a . This new material contains carbon, boron, and nitrogen, and its chemical name is “Hexagonal Boron-Carbon-Nitrogen (h-BCN)”. The new development was published in the journal ACS Nano.

2D material Bayreuth University

Our findings could be the starting point for a new generation of electronic transistors, circuits, and sensors that are much smaller and more bendable than the electronic elements used to date. They are likely to enable a considerable decrease in power consumption,” Prof. Enders predicts, citing the CMOS technology that currently dominates the electronics industry. This technology has clear limits with regard to further miniaturization. “h-BCN is much better suited than graphene when it comes to pushing these limits,” according to Enders.

Graphene is a two-dimensional lattice made up entirely of carbon atoms. It is thus just as thin as a single atom. Once scientists began investigating these structures more closely, their remarkable properties were greeted with enthusiasm across the world. Graphene is 100 to 300 times stronger than steel and is, at the same time, an excellent conductor of heat and electricity.

Source: https://www.uni-bayreuth.de/

NonCarbon SuperCapacitor Produces More Power

Energy storage devices called supercapacitors have become a hot area of research, in part because they can be charged rapidly and deliver intense bursts of power. However, all supercapacitors currently use components made of carbon, which require high temperatures and harsh chemicals to produce. Now researchers at MIT and elsewhere have for the first time developed a supercapacitor that uses no conductive carbon at all, and that could potentially produce more power than existing versions of this technology.

mit-supercapacitor

We’ve found an entirely new class of materials for supercapacitors,” Dincă says.

Dincă and his team have been exploring for years a class of materials called metal-organic frameworks, or MOFs, which are extremely porous, sponge-like structures. These materials have an extraordinarily large surface area for their size, much greater than the carbon materials do. That is an essential characteristic for supercapacitors, whose performance depends on their surface area. But MOFs have a major drawback for such applications: They are not very electrically conductive, which is also an essential property for a material used in a capacitor.

One of our long-term goals was to make these materials electrically conductive,” Dincă says, even though doing so “was thought to be extremely difficult, if not impossible.” But the material did exhibit another needed characteristic for such electrodes, which is that it conducts ions (atoms or molecules that carry a net electric charge) very well.

All double-layer supercapacitors today are made from carbon,” Dincă says. “They use carbon nanotubes, graphene, activated carbon, all shapes and forms, but nothing else besides carbon. So this is the first noncarbon, electrical double-layer supercapacitor.”

The team’s findings are being reported in the journal Nature Materials, in a paper by Mircea Dincă, an MIT associate professor of chemistry; Yang Shao-Horn, the W.M. Keck Professor of Energy; and four others.

Source: http://news.mit.edu/

Tiny Diamonds Revolutionize Nanotechnology

Nanomaterials have the potential to improve many next-generation technologies. They promise to speed up computer chips, increase the resolution of medical imaging devices and make electronics more energy efficient. But imbuing nanomaterials with the right properties can be time consuming and costly. A new, quick and inexpensive method for constructing diamond-based hybrid nanomaterials in bulk could launch the field from research to applications. University of Maryland (UMD) researchers developed a method to build diamond-based hybrid nanoparticles in large quantities from the ground up, thereby circumventing many of the problems with current methods.

The process begins with tiny, nanoscale diamonds that contain a specific type of impurity: a single nitrogen atom where a carbon atom should be, with an empty space right next to it, resulting from a second missing carbon atom. This “nitrogen vacancyimpurity gives each diamond special optical and electromagnetic properties. By attaching other materials to the diamond grains, such as metal particles or semiconducting materials known as “quantum dots,” the researchers can create a variety of customizable hybrid nanoparticles, including nanoscale semiconductors and magnets with precisely tailored properties.

nanodiamonds

If you pair one of these diamonds with silver or gold nanoparticles, the metal can enhance the nanodiamond’s optical properties. If you couple the nanodiamond to a semiconducting quantum dot, the hybrid particle can transfer energy more efficiently,” said Min Ouyang, an associate professor of physics at UMD and senior author on the study.

The technique is described in the June 8 issue of the journal Nature Communications.

Source: http://umdrightnow.umd.edu/

Graphene Enhances Strength And Elasticity Of Condoms

Dr Aravind Vijayaraghavan and Dr Maria Iliut from Manchester University (UK)  have shown that adding a very small amount of graphene, the world’s thinnest and strongest material, to rubber films can increase both their strength and the elasticity by up to 50%. Thin rubber films are ubiquitous in daily life, used in everything from gloves to condoms.

graphene-rubber

In their experiments, the scientists tested two kinds of rubbery materials natural rubber, comprised of a material called polyisoprene, and a man-made rubber called polyurethane. To these, they added graphene of different kinds, amounts and size.

In most cases, it they observed that the resulting composite material could be stretched to a greater degree and with greater force before it broke. Indeed, adding just one tenth of one percent of graphene was all it took to make the rubber 50% stronger.

Dr Vijayaraghavan, who leads the Nano-functional Materials Group, explains “A composite is a material which contains two parts, a matrix which is soft and light and a filler which is strong. Taken together, you get something which is both light and strong. This is the principle behind carbon fibre composites used in sports cars, or Kevlar composites used in body armour. In this case, we have made a composite of rubber, which is soft and stretchy but fragile, with graphene and the resulting material is both stronger and stretchier.”

The research has been published in the journal  Carbon,

Source: http://www.manchester.ac.uk/

Electric Car: Safer, Cheaper Rechargeable Batteries

By chemically modifying and pulverizing a promising group of compounds, scientists at the National Institute of Standards and Technology (NIST) have potentially brought safer, solid-state rechargeable batteries two steps closer to reality.

sodiumChunks of this sodium-based compound (Na2B12H12) (left) would function well in a battery only at elevated temperatures, but when they are milled into far smaller pieces (right), they can potentially perform even in extreme cold, making them even more promising as the basis for safer, cheaper rechargeables.

These compounds are stable solid materials that would not pose the risks of leaking or catching fire typical of traditional liquid battery ingredients and are made from commonly available substances. Since discovering their properties in 2014, a team led by NIST scientists has sought to enhance the compounds’ performance further in two key ways: Increasing their current-carrying capacity and ensuring that they can operate in a sufficiently wide temperature range to be useful in real-world environments.

Considerable advances have now been made on both fronts, according to Terrence Udovic of the NIST Center for Neutron Research, whose team has published a pair of scientific papers that detail each improvement.  The first advance came when the team found that the original compounds — made primarily of hydrogen, boron and either lithium or sodium — were even better at carrying current with a slight change to their chemical makeup. Replacing one of the boron atoms with carbon improved their ability to conduct charged particles, or ions, which are what carry electricity inside a battery. As the team reported in February in their first paper, the switch made the compounds about 10 times better at conducting.

But perhaps more important was clearing the temperature hurdle. The compounds conducted ions well enough to operate in a battery — as long as it was in an environment typically hotter than boiling water. Unfortunately, there’s not much of a market for such high-temperature batteries, and by the time they cooled to room temperature, the materials’ favorable chemical structure often changed to a less conductive form, decreasing their performance substantially. One solution turned out to be crushing the compounds’ particles into a fine powder.

This approach can remove worries about whether batteries incorporating these types of materials will perform as expected even on the coldest winter day,” said Udovic, whose collaborators on the most recent paper include scientists from Japan’s Tohoku University, the University of Maryland and Sandia National Laboratories. “We are currently exploring their use in next-generation batteries, and in the process we hope to convince people of their great potential.”

Source: http://nist.gov

Cost-effective Hydrogen Production From Water

Groundbreaking research at Griffith University (Australia) is leading the way in clean energy, with the use of carbon as a way to deliver energy using hydrogen. Professor Xiangdong Yao and his team from Griffith’s Queensland Micro- and Nanotechnology Centre have successfully managed to use the element to produce hydrogen from water as a replacement for the much more costly platinum.

Tucson fuel cellTucson fom Hyundai: A Hydrogen Fuel Cell Car

Hydrogen production through an electrochemical process is at the heart of key renewable energy technologies including water splitting and hydrogen fuel cells,” says Professor Yao. “Despite tremendous efforts, exploring cheap, efficient and durable electrocatalysts for hydrogen evolution still remains a great challenge. “Platinum is the most active and stable electrocatalyst for this purpose, however its low abundance and consequent high cost severely limits its large-scale commercial applications. “We have now developed this carbon-based catalyst, which only contains a very small amount of nickel and can completely replace the platinum for efficient and cost-effective hydrogen production from water.

In our research, we synthesize a nickel–carbon-based catalyst, from carbonization of metal-organic frameworks, to replace currently best-known platinum-based materials for electrocatalytic hydrogen evolution“, he adds. “This nickel-carbon-based catalyst can be activated to obtain isolated nickel atoms on the graphitic carbon support when applying electrochemical potential, exhibiting highly efficient hydrogen evolution performance and impressive durability.”

Proponents of a hydrogen economy advocate hydrogen as a potential fuel for motive power including cars and boats and on-board auxiliary power, stationary power generation (e.g., for the energy needs of buildings), and as an energy storage medium (e.g., for interconversion from excess electric power generated off-peak).

Source: https://app.secure.griffith.edu.au/

Candle Soot Powers Lithium Ion Battery

A new study reveals that carbon from candle soot could be used to power the kind of lithium ion battery in plug-in hybrid electric cars. Researchers from the Indian Institute of Technology in Hyderabad, India claim that their findings could open up possibilities for using carbon in more powerful batteries, which could drive down the costs of portable power.

Lithium ion batteries are used to power a wide range of devices, including smartphones, digital cameras, electric cars and even aircraft. The batteries produce current through two electrically charged materials suspended in a liquid. Carbon, while used as one of the materials in smaller batteries, is considered unsuitable for bigger and more powerful batteries because of its structure, which cannot produce the required current density.

In the new study, published in the journal Electrochimica Acta, the researchers found that because of the shape and configuration of the tiny carbon nanoparticles, the carbon in candle soot could be used in bigger batteries. The team also said that their research introduces a more scalable approach to making batteries because the soot could be produced quickly and easily.

soot

If you put water droplet on candle soot it rolls off – that’s an observation that’s been made in the last few years. The material candle soot is made of, carbon, also has electric potential. So why not use it as an electrode? We looked into it and saw it also shows some exceptional electrochemical properties, so we decided to test it further,” said Dr Chandra Sharma, one of the study’s authors.

Using a technique called cyclic charge-discharge, or CCD, the researchers analysed the effectiveness of soot as a conducting material to use in a battery. The technique shows how powerful the battery is based on the rate of charge or discharge: the higher the rate, the more powerful the battery. According to the study’s results, the candle soot carbon performed better at higher rates.

Sharma said the technology is not only efficient and cost-effective but also scalable, which could make battery production cheaper. One hybrid car would need approximately 10 kilograms of carbon soot, which would be deposited in about an hour using candles, Sharma explained.

Source: http://www.sciencedirect.com/
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http://www.ibtimes.com.au/

How To Boost Battery Performance

Stanford University scientists have created a new carbon material that significantly boosts the performance of energy-storage technologies.
designer-carbon-300x200
A new ”designer carbon” invented by Stanford scientists significantly improved the power-delivery rate of this supercapacitor

We have developed a ‘designer carbon’ that is both versatile and controllable,” said Zhenan Bao, the senior author of the study and a professor of chemical engineering at Stanford. “Our study shows that this material has exceptional energy-storage capacity, enabling unprecedented performance in lithium-sulfur batteries and supercapacitors.”

According to Bao, the new designer carbon represents a dramatic improvement over conventional activated carbon, an inexpensive material widely used in products ranging from water filters and air deodorizers to energy-storage devices.

A lot of cheap activated carbon is made from coconut shells,” Bao said. “To activate the carbon, manufacturers burn the coconut at high temperatures and then chemically treat it.

The findings are featured on the cover of the journal ACS Central Science.

Source: http://news.stanford.edu/

How To Turn Algae Into Solar Powered Factories

Genes from the family of bacteria that produce vinegar, Kombucha tea and nata de coco have become stars in a project that would turn algae into solar-powered factories for producing the “wonder materialnanocellulose. Reports on advances in getting those genes to produce fully functional nanocellulose were part of the 245th National Meeting & Exposition of the American Chemical Society (ACS), the world’s largest scientific society.
Nanocellulose
If we can complete the final steps, we will have accomplished one of the most important potential agricultural transformations ever,” said R. Malcolm Brown, Jr., Ph.D. “We will have plants that produce nanocellulose abundantly and inexpensively. It can become the raw material for sustainable production of biofuels and many other products. While producing nanocellulose, the algae will absorb carbon dioxide, the main greenhouse gas linked to global warming.

Most cellulose consists of wood fibers and cell wall remains. Very few living organisms can actually synthesize and secrete cellulose in its native nanostructure form of microfibrils. At this level, nanometer-scale fibrils are very hydrophilic and look like jelly. A nanometer is one-millionth the thickness of a U.S. dime. Nevertheless, cellulose shares the unique properties of other nanometer-sized materials — properties much different from large quantities of the same material. Nanocellulose-based materials can be stronger than steel and stiffer than Kevlar. Great strength, light weight and other advantages has fostered interest in using it in everything from lightweight armor and ballistic glass to wound dressings and scaffolds for growing replacement organs for transplantation.

Source: http://www.eurekalert.org/