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LEDs can be cooled by graphene-based films

07/01/2016

(Resource: BIZ LED)

Electronics can now be efficiently cooled using graphene-based film, claim researchers from Chalmers University of Technology.

They added that the graphene film has thermal conductivity four times higher than that of copper. The researchers have further developed a graphene film that can be attached to silicon substrates.

A professor at Chalmers University of Technology and the research team leader Johan Liu wrote: “The methods currently in place, have inconvenienced the researchers making it evident that those methods cannot be used to rid electronic devices off immense amounts of heat, because they consist of only a few layers of thermal conductive atoms.”

“Another problem arises, when you try to add more layers of graphene, a trouble with adhesiveness. The graphene no longer will stick to the surface, after having improved the amount of layers; since the bond is held together only by weak van der Waals bonds,” he added.

He continued, “We have now solved this dilemma by managing to form strong covalent bonds between the surface and the graphene film, which is an electronic component made of silicon.”

The addition of property altering molecule results in a stronger bond of the graphene. The addition of (3-Aminopropyl) triethoxysilane (APTES) molecules has the required effect, concluded the researchers at Chalmers University of Technology.

The so-called silane bonds are created between the electronic component and graphene through hydrolysis and heating. Johan Liu added that a possible application is the graphene-based film being integrated into lasers, LEDs and radio frequency apparatus for cooling function.


Read Also 10 Top Graphite-producing Countries

http://investingnews.com/daily/resource-investing/critical-metals-investing/graphite-investing/top-graphite-producing-countries-china-india-brazil-canada/


Graphite is an excellent conductor of heat and electricity, and also has the highest strength of any natural material. However, it wasn’t until recently that the metal began to gain popularity.

Interest in graphite is increasing in large part becauselithium-ion batteries, which are used in everything from phones to modern vehicles, are becoming more and more common. Graphite is a key component of those batteries, and as their use increases, graphite production is only expected to rise.

On that note, it’s interesting to look at which countries are currently producing the most graphite. Here’s a look at the nations that put out the most of the metal in 2014, based onnumbers from the US Geological Survey (USGS).

1. China

Mine Production: 780,000 MT

China is the largest producer of graphite in the world, and in 2014 it put out 780,000 MT of the metal, more than 2013’s 750,000 MT. While that’s a significant jump, industry experts do not expect similar spikes in the future — in 2014, the Asian nation suspended production at many of its flake graphite mines due to pollution concerns, and according to Simon Moores of Benchmark Mineral Intelligence, many restarts have been delayed.

“Although mines and processing plants have now been given permission to begin production again, weak market conditions saw many reduce output prior to the winter season, with the majority of miners yet to bring capacities back online,” said Moores in a recent note, adding, “[a]s regional governments put further emphasis on the development of value-added industries domestically, demand from these markets will increase and supply availability to the rest of the world will fall.”

2. India

Mine production: 170,000 MT

Significantly behind China, but still in the number-two spot, is India. Last year, the country produced about the same amount of graphite as it did in 2013.

Graphite India (NSE:GRAPHITE), which began operating in the 1960s, is a key player in the nation’s graphite sector, though it’s focused on producing graphite electrodes, not mining the metal. That said, other companies are trying to make their way into the mix. KS Mines, for example, is looking to restart a flake graphite mine in the country.



3. Brazil

Mine production: 80,000 MT

Brazil produced 80,000 MT of graphite in 2014, less than the 95,000 MT it put out in 2013. However, Brazil is South America’s only producer of graphite, and that has made the country popular for investors and companies in recent years.

One graphite-focused company currently operating in Brazil is Lara Exploration (TSXV:LRA). It’s focused on the Caninde project, and recently intersected 13.69 meters grading 18.38 percent graphitic carbon at the Pedra Preta target.

4. Canada

Mine production: 30,000 MT

Canada’s graphite production increased by 10,000 MT from 2013 to 2014. That might sound surprising, but Business News Network recently reported that the country has been putting an increasing amount of effort into graphite production and exploration in recent years. Indeed, the news outlet states that Canada has played host to events that are like “speed dating for prospective producers and potential investors.”

Though listed as number four on this list, the country is actually tied in production with both North Korea and Turkey.

5. North Korea

Mine production: 30,000 MT

Graphite production in North Korea kept relatively even from 2013 to 2014. As noted, it’s tied for fourth-largest producer with Canada and Turkey. That said, while North Korea’s graphite production is fairly significant, there is little data on the country’s mining activities, as per The Wall Street Journal.

6. Turkey

Mine production: 30,000 MT

Turkey saw an impressive 25,000-MT jump in graphite production from 2013 to 2014, allowing it to tie with Canada and North Korea. Turkey’s graphite production has been irregular over the years, and little further information is available regarding its production.

Graphite One Resources Inc. (TSXV:GPH,OTCQX:GPHOF) is advancing the Graphite Creek Deposit in Alaska which is North America’s largest known large flake graphite deposit. Connect with Graphite Once Resources to instantly receive their next catalyst.

7. Russia

Mine production: 14,000 MT

Russia’s graphite production has only been tracked by the USGS for the last three years, and each time it has produced the same amount of graphite. The first year it was listed was 2012, the same year it decided to increase its graphite production, as per InvestorIntel.

Prior to that time, the country had faced a shortage of graphite. The government then created incentives for private investors to explore and develop new deposits.

8. Mexico

Mine production: 8,000 MT

Mexico’s graphite production increased last year, rising to 8,000 MT from 7,000 MT in 2013. That amount may rise further in the coming years — Big North Graphite (TSXV:NRT) reiterated this past April that it plans to reopen the El Tejon flake mine and mill, which closed in 2002 due to low prices. However, the company still needs to raise some money in order to do so.

9. Ukraine

Mine production: 6,000 MT

Ukraine kept even with its 2013 production rate at 6,000 MT, tying with Zimbabwe in terms of output. The Zavalye mine is the country’s largest graphite producer; little other data exists on its production.

10. Zimbabwe

Mine production: 6,000 MT

As mentioned, Zimbabwe tied with Ukraine to produce 6,000 MT of graphite in 2014. That’s an increase for Zimbabwe, which produced 4,000 MT in 2013. According to The People’s Voice, Zimbabwe is only one of two countries in Africa to host developed natural graphite mines. The Chamber of Mines of Zimbabwe states that Lynx mine is the only mine producing graphite in the country.