Alan MacDiarmid chemist, Nobel laureate discovered, developed conductive polymers

Alan MacDiarmid – discoverer of conductive polymers

Category : Personalities
Published by : Data Research Analyst, Worldofchemicals.com

Biography & Contributions

Alan MacDiarmid was a chemist and Nobel laureate born on April 14, 1927 – died on February 07, 2007. MacDiarmid was discovered and developed plastic materials through which electric current can flow.

He got several awards and medals like The Francis J. Clamer Medal in the year of 1993, MacDiarmid got American Chemical Society Award in the year of 1999, Rutherford Medal, Nobel Prize for Chemistry in the year of 2000.

The development of plastic batteries began with an accident. In the early 1970s, a graduate student in Japan was trying to repeat the synthesis of polyacetylene, a dark powder made by linking together the molecules of ordinary acetylene welding gas. After the chemical reaction took place, instead of a black powder, the student found a film coating the inside of his glass reaction vessel that looked much like aluminum foil. MacDiarmid later realized that he had inadvertently added much more than the recommended amount of catalyst to cause the acetylene molecules to link together.

MacDiarmid's team reasoned that the ability of polyacetylene to conduct electricity was probably promoted by trace impurities contributed by the catalysts involved in the Japanese student's process. MacDiarmid's team confirmed that it was possible to chemically dope polyacetylene to create either mobile excess electrons or holes. That these electrons and holes could move explained how polyacetylene was able to conduct electricity.

When polyacetylene was exposed to traces of iodine or bromine vapor, the thin polymer film exhibited still higher electrical conductivity. The researchers discovered that by purposefully adding selected impurities to polyacetylene.

Conductive plastics have been developed into many useful applications such as lightweight electromagnetic shields and ‘smart’ windows that can vary the amount of light they allow to pass. Single molecule electrical circuits connected by conducting polymers may be the electronics of the future; playing a major role in the development of new electronic devices. The application of the research into plastic circuitry is at the forefront of nanotech innovation and on the brink of transforming information technology.

Chemically, the plastic battery is different from conventional metal-based rechargeable batteries in which material from one plate migrates to another plate and back in a reversible chemical reaction. In a conducting plastic battery, only the stored ions of the solution move-the plates are not consumed and reconstituted. Since conventional battery life is limited by the number of times the plates can be reconstituted, this difference portends a longer recharge-cycle lifetime for the plastic batteries.

Polyacetylene


Polyacetylene is an important organic polymer with the repeating unit (C2H2)n. Polyacetylene consists of a long chain of carbon atoms with alternating single and double bonds between them, each with one hydrogen atom. Polyacetylene can be synthesized by ring-opening metathesis polymerization (ROMP) from cyclooctatetraene, a material easier to handle than the acetylene monomer.

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