Tag Archives: insulation

A use for fullerenes—inside insulation plastic for high-voltage cables

A Jan. 27, 2015 news item on Nanowerk, describes research which suggests that there may a new use for buckminsterfullerenes (or what they’re calling ‘carbon nanoballs’),

Researchers at Chalmers University of Technology [Sweden] have discovered that the insulation plastic used in high-voltage cables can withstand a 26 per cent higher voltage if nanometer-sized carbon balls are added. This could result in enormous efficiency gains in the power grids of the future, which are needed to achieve a sustainable energy system.

The renewable energy sources of tomorrow will often be found far away from the end user. Wind turbines, for example, are most effective when placed out at sea. Solar energy will have the greatest impact on the European energy system if focus is on transport of solar power from North Africa and Southern Europe to Northern Europe.

“Reducing energy losses during electric power transmission is one of the most important factors for the energy systems of the future,” says Chalmers researcher Christian Müller. “The other two are development of renewable energy sources and technologies for energy storage.”

The Jan. 27, 2015 Chalmers University of Technology press release (also on EurekAlert) by Johanna Wilde, which originated the news item, provides more information about the research,

Together with colleagues from Chalmers and the company Borealis in Stenungsund, he [Müller] has found a powerful method for reducing energy losses in alternating current cables.  The results were recently published in Advanced Materials, a highly ranked scientific journal.

The researchers have shown that different variants of the C60 carbon ball, a nanomaterial in the fullerene molecular group, provide strong protection against breakdown of the insulation plastic used in high-voltage cables. Today the voltage in the cables has to be limited to prevent the insulation layer from getting damaged. The higher the voltage the more electrons can leak out into the insulation material, a process which leads to breakdown.

It is sufficient to add very small amounts of fullerene to the insulation plastic for it to withstand a voltage that is 26 per cent higher, without the material breaking down, than the voltage that plastic without the additive can withstand.

“Being able to increase the voltage to this extent would result in enormous efficiency gains in power transmission all over the world,” says Christian Müller. “A major issue in the industry is how transmission efficiency can be improved without making the power cables thicker, since they are already very heavy and difficult to handle.”

Using additives to protect the insulation plastic has been a known concept since the 1970s, but until now it has been unknown exactly what and how much to add. Consequently, additives are currently not used at all for the purpose, and the insulation material is manufactured with the highest possible degree of chemical purity.

In recent years, other researchers have experimented with fullerenes in the electrically conductive parts of high-voltage cables. Until now, though, it has been unknown that the substance can be beneficial for the insulation material.

The Chalmers researchers have now demonstrated that fullerenes are the best voltage stabilizers identified for insulation plastic thus far. This means they have a hitherto unsurpassed ability to capture electrons and thus protect other molecules from being destroyed by the electrons.

To arrive at these findings, the researchers tested a number of molecules that are also used within organic solar cell research at Chalmers. The molecules were tested using several different methods, and were added to pieces of insulation plastic used for high-voltage cables. The pieces of plastic were then subjected to an increasing electric field until they crackled. Fullerenes turned out to be the type of additive that most effectively protects the insulation plastic.

The press release includes some facts about buckyballs or buckminsterfullerenes or fullerenes or C60 or carbon nanoballs, depending on what you want to call them,

 Facts: Carbon ball C60

  • The C60 carbon ball is also called buckminsterfullerene. It consists of 60 carbon atoms that are placed so that the molecule resembles a nanometer-sized football. C60 is included in the fullerene molecular class.
  • Fullerenes were discovered in 1985, which resulted in the Nobel Prize in Chemistry in 1996. They have unique electronic qualities and have been regarded as very promising material for several applications. Thus far, however, there have been few industrial usage areas.
  • Fullerenes are one of the five forms of pure carbon that exist. The other four are graphite, graphene/carbon nanotubes, diamond and amorphous carbon, for example soot.

Here’s a link to and a citation for the research paper,

A New Application Area for Fullerenes: Voltage Stabilizers for Power Cable Insulation by Markus Jarvid, Anette Johansson, Renee Kroon, Jonas M. Bjuggren, Harald Wutzel, Villgot Englund, Stanislaw Gubanski, Mats R. Andersson, and Christian Müller. Advanced Materials DOI: 10.1002/adma.201404306 Article first published online: 12 DEC 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Here’s an image of wind turbines, an example of equipment which could benefit greatly from better insulation.,

Images: Lina Bertling, Jan-Olof Yxell, Carolina Eek Jaworski, Anette Johansson, Markus Jarvid, Christian Müller

Images: Lina Bertling, Jan-Olof Yxell, Carolina Eek Jaworski, Anette Johansson, Markus Jarvid, Christian Müller

You can find this image and others by clicking on the Chalmers University press release link (assuming the page hasn’t been moved). You can find more information about Borealis (the company Müller is working with) here.

Solid smoke; a new generation of aerogels

The latest American Chemical Society (244th) meeting (Fall 2012, Aug. 19 – 23, 2012) includes a presentation on one of my favourite topics ‘solid smoke’ or aerogel, as it’s called more commonly.

From the Aug. 19, 2012 news item on Nanowerk (Note: I have removed a reference to a video on previous generations of aerogels that the folks at Nanowerk found and included with this news item),

A major improvement in the world’s lightest solid material and best solid insulating material, described here today, may put more of this space-age wonder into insulated clothing, refrigerators with thinner walls that hold more food, building insulation and other products.

The report, on development of a new flexible “aerogel” — stuff so light it has been called “solid smoke” — was part of the 244th National Meeting & Exposition of the American Chemical Society, the world’s largest scientific society. …

Mary Ann B. Meador, Ph.D., explained that traditional aerogels, developed decades ago and made from silica, found in beach sand, are brittle, and break and crumble easily. Scientists have improved the strength of aerogels over the years, and Meador described one of these muscled-up materials developed with colleagues at the NASA Glenn Research Center in Cleveland, Ohio.

The Aug. 19, 2012 news release from the American Chemical Society, which originated the news item, describes this new generation of aerogels’ strength and potential applications,

“The new aerogels are up to 500 times stronger than their silica counterparts,” Meador said. “A thick piece actually can support the weight of a car. And they can be produced in a thin form, a film so flexible that a wide variety of commercial and industrial uses are possible.”

Flexible aerogels, for instance, could be used in a new genre of super-insulating clothing that keeps people warm in the cold with less bulk than traditional “thermal” garments. Tents and sleeping bags would have the same advantages. Home refrigerator and freezer walls insulated with other forms of the material would shrink in thickness, increasing storage capacity. Meador said that the aerogel is 5-10 times more efficient than existing insulation, with a quarter-inch-thick sheet providing as much insulation as 3 inches of fiberglass. And there could be multiple applications in thin-but-high-efficiency insulation for buildings, pipes, water heater tanks and other devices.

NASA envisions one use in an advanced re-entry system for spacecraft returning to Earth from the International Space Station, and perhaps other missions. Re-entry vehicles need a heat shield that keeps them from burning up due to frictional heating from Earth’s atmosphere. Those shields can be bulky and heavy. So NASA is exploring use of a heat shield made from flexible aerogel that inflates like a balloon when spacecraft enter the atmosphere.

Meador said the material also could be used to insulate spacesuits. However, it likely would not be good for firefighting clothing products, which require protection beyond the 575 degrees Fahrenheit limits of the aerogel.

The scientists also offered a brief explanation of how these new aerogels are made (from the ACS news release),

Scientists produced the stronger new aerogels in two ways. One involved making changes in the innermost architecture of traditional silica aerogels. They used a polymer, a plastic-like material, to reinforce the networks of silica that extend throughout an aerogel’s structure. Another involved making aerogels from polyimide, an incredibly strong and heat-resistant polymer, or plastic-like material, and then inserting brace-like cross-links to add further strength to the structure.

My last mention of ‘solid smoke’ was in my Mar.27, 2012 posting about the 243rd meeting of the American Chemical Society held in Spring 2012.