Plastic magnet breaks the mold
After three months of mostly fruitless experiments, researchers at the U.K. university began to detect magnetism in a mixture of two plastic polymers, and the compound has now passed its first real test: It can pick up iron filings.
Although magnetic plastics have been reported before, they have only worked at extremely low temperatures. The Durham compound--made out of a conductive plastic called emeraldine base polyaniline (PANi) and a free radical generator called tetracyanoquinodimethane--is active at room temperatures.
Researcher Naveed Zaidi told New Scientist that although the compound is only weakly magnetic, there is much room for improvement. "The reaction is not yet 100 percent efficient along the polymer, and the strength of effect varies throughout the material. Once we increase this efficiency, this overall strength will certainly increase," Zaidi said.
Future uses of the plastic mold could include coatings for computer hard disks and components in medical implants, as the body is much more tolerant of plastic than metal.
PANi has been under investigation by a number of institutions because of its conductive properties: It has been shown to act as a light-emitting diode and to have potential uses in infrared optics. It's also used in fuel cells and is a member of a larger class of conductive plastics that are beginning to be used in industry.
However, there remains a great deal of work to do before any practical application for the magnetic variant is found, material scientist Jerry Torrance said. He told New Scientist that the discovery was nevertheless "a significant scientific breakthrough."
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