Nobel prize recognizes future for plastics

This year’s Nobel Prize in Chemistry goes to three researchers for the discovery and development of plastics that conduct electricity as metals and semiconductors do. Their work, which began with a serendipitous discovery a quarter century ago, has opened a new world of applications for plastics.

The Royal Swedish Academy of Sciences awarded the prize to Alan J. Heeger of the University of California, Santa Barbara, Alan G. MacDiarmid of the University of Pennsylvania in Philadelphia, and Hideki Shirakawa of the University of Tsukuba in Japan.

Their legacy of conductive polymers now affects a range of applications and ongoing development, including antistatic materials, antirust coatings, batteries, and so-called smart windows that turn dark in sunlight. Researchers are also developing semiconductive polymers for use in light-emitting diodes, solar cells, lasers, and mobile-telephone displays.

Because they’re easy to process, semiconductive plastics could considerably lower the price of simple electronic devices, says George Malliaras of Cornell University, whose research includes studies of semiconducting polymers. “Inexpensive electronics will revolutionize our everyday life,” he predicts.

Yet the awardees’ initial work, in the 1970s, was basic science “done purely from the point of view of curiosity,” MacDiarmid told Science News.

Until that time, plastics were generally known as insulators. Then came the accident. While Shirakawa was trying a new way to synthesize the carbon-containing polymer called polyacetylene, one of his experimental reactions received 1,000 times as much catalyst as he intended.

The result: a striking silvery film.

MacDiarmid first heard about the polymer during a seminar coffee break with Shirakawa. At the time, MacDiarmid had been working with Heeger on a metallic-looking film of another polymer. MacDiarmid invited Shirakawa to his lab in Philadelphia, where they and Heeger found that treating polyacetylene with iodine vapor—a process called doping—increases the material’s electrical conductivity by a factor of up to a billion.

“This work ignited a field,” comments chemist and physicist Arthur J. Epstein of Ohio State University in Columbus. “I am delighted that it has now been recognized by the Nobel committee.” Adds MacDiarmid: “I feel that this award is really an extremely big boost for interdisciplinary science.” The research on conductive polymers has brought together chemists, physicists, electrical engineers, and others.

“You can’t explain how you feel” upon winning the Nobel, Heeger told Science News. “I knew it was important work back in the 1970s . . . but it took help from colleagues all over the world to bring those early ideas to a reality that will make these materials important in technology and lead to real products.”

MacDiarmid says he had no idea the award was coming. “It’s like if you go to Las Vegas and you put a coin in the slot,” he says. “There’s always the chance that you may win the $10 million jackpot, but you don’t ever really believe that you will.”

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