04/26/2006
Carbon Nanotubes Hit the Ice
Last week my wife and I had the good fortune to attend a concert at Lincoln Center with Mstislav Rostropovich conducting the New York Philharmonic. Rostropovich, who was so close with Shostakovich in the USSR that he considered Shostakovich like a father, appropriately conducted the composer’s Symphony No. 10 and his Violin Concerto No. 1. The latter work featured as soloist the 31-year-old Siberian-born violinist Maxim Vengerov, whose breathtaking performance elicited tumultuous cheers and bravos from the audience. The program notes quoted violinist Venyamin Basner as describing the concerto as a “relentlessly hard, intense piece for the soloist”. It certainly is. Prior to the concerto’s premiere in Leningrad in 1955, violinist David Oistrakh pleaded with Shostakovich to show him mercy by letting the orchestra take over the first bars of the finale so as to give Oistrakh a break to “wipe the sweat off my brow”! The composer agreed and revised the score so both Oistrakh and Vengerov could catch their breaths before the demanding finale.
I felt that we were witnessing the passing of the torch from the 78 or 79-year-old Rostropovich to Vengerov, who is also a conductor. Rostropovich, a renowned cellist and former music director of the National Symphony Orchestra of Washington, D.C., is probably one of the few who have won the USSR’s Lenin Prize and the U.S.’s Presidential Medal of Freedom and he also shared music’s prestigious Polar Prize with Sir Elton John. He not only was a staunch defender of Solzhenitsyn during the Soviet period but also went to Moscow in 1991 to stand with those in the Russian “White House” fighting the unsuccessful coup attempt.
Shostakovich was a controversial figure, alternating between being condemned or praised during the Stalin regime. In fact, the Symphony No. 10 that we heard was finished soon after Stalin’s death and purportedly is a depiction of Stalin and his times. This powerful work really brought out the amazing musicianship of the Philharmonic. I especially never cease to marvel about the string sections, which can sound as one even in the most complicated passages that include rapid plucking of the strings transitioning immediately into “normal” bowing.
One thing about a performance of Shostakovich’s major works – you never leave humming a melody from the concert. However, you will likely not forget the visceral experience. In the program notes for our concert, James Keller described the controversy among musical scholars about the messages and meanings of Shostakovich’s works. Keller suggests they are like the Russian matryoshka dolls. As with these dolls stacked inside each other, Keller feels that just when you get comfortable, Shostakovich twists the music apart to reveal another surprise inside.
Which leads me to the Shostakovich of elemental chemistry – carbon, an element that I return to every so often as new surprises are revealed. Our editor, Brian Trumbore, mentions carbon in his Week in Review columns in connection with his investment in the stock of a carbon fiber company. Carbon can be the world’s hardest material, diamond, or one of its softer materials, graphite – the “lead” in your pencil. We’ve talked about fullerenes, in which carbon may be a buckyball (60 carbon atoms arranged in a structure resembling a soccer ball) or a nanotube. In a carbon nanotube, carbon atoms are arranged in hexagons in a structure resembling a tube of rolled up chicken wire.
You might not think that rolled up carbon “chicken wire” would be exciting. Yet the amount of work on carbon nanotubes worldwide is astounding and for good reason. A July 1, 2005 article on the Web site of the National Research Council (NRC) of Canada describes carbon nanotubes as “ the world’s ultimate material”! The article supports this view by noting that carbon nanotubes are a hundred times stronger than steel and are the best conductors of heat and electricity known to science. Carbon nanotubes can also be superconductors as well as semiconductors depending on how they’re tweaked mechanically or chemically. They are indeed remarkable materials but there is a catch,
The catch lies in the “nano” in nanotube. These things are truly tiny and to make any significant quantity of them has been a challenge. The NRC article gives the world’s total production as only 300 kilograms (about 660 pounds) a year and you could pay up to $600 a gram to buy some. Nevertheless, the title of the NRC article, “Building the Perfect Hockey Stick or Aircraft – Carbon Nanotubes”, suggests that something is in the wings in the way of mass production and cost reduction for the carbon nanotube. And wouldn’t you know that, based in Canada, one would think of an application in a hockey stick? Indeed, the article describes an effort at NRC and the University of Sherbrooke to mass-produce the nanotubes and then form a composite resin containing the nanotubes. If the composite performs well in the hockey stick, then it’s on to test the waters in the aerospace market.
That was last year. Sure enough, I spotted a news item dated March 6, 2006 in the Materials Research Society’s Materials News that said a Finnish company has put multiwalled carbon nanotubes in its ice hockey sticks. (Nanotubes come in single- walled form or multiwalled form. In a single-walled nanotube, the chicken wire structure is only one atom thick. In a multiwalled nanotube, it’s like stacking chicken wire tubes inside each other.) Well, I searched the Web for more on this development and came up with the name of the Finnish company - Montreal Sports! They’re serious and are marketing the new “Nitro Lite” hockey sticks as having 60-70 percent greater impact resistance and greater flexibility for better puck feel and handling. And the Stanley Cup playoffs are just beginning. The sticks reportedly have better flexibility compared to a composite containing carbon fiber (sorry about that, Brian).
Montreal Sports uses nanotubes supplied by Bayer in Germany. A visit to the Bayer MaterialScience Web site indicates that they have a continuous cost-effective process for producing carbon nanotubes, which look like black dust to the naked eye. They don’t give a price but do say they have lowered the cost below 1,000 euros per kilogram, roughly a dollar a gram. Whatever the figure, it’s clear that the cost trend is down and conducive to commercial applications.
Aside from hockey sticks, research continues that may open up new fields. One new field may have been opened up by Boston College professors Jianyu Huang and Zhifeng Ren and their students. They have made single-walled carbon nanotubes “superstretchy” according to an article by Bethany Halford in the January 23 Chemical and Engineering News. Single-walled carbon nanotubes are very strong at room temperature and workers haven’t been able to stretch them more than a few percent before they break. However, the Boston researchers found that when they put a voltage of a little over 2 volts across one of these nanotubes they could stretch the little bugger more than three times its length before it breaks.
They attribute this stretchiness to the fact that the current that passes through the nanotube heats it up to about 2,000 degrees Centigrade and the carbon atoms rearrange themselves when the tube is pulled. This effect at high temperatures may be simply a scientific curiosity or it might open up a new field of uses for carbon nanotubes in high temperature composites, not just low temperature hockey sticks.
Allen F. Bortrum
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