Printer Friendly

Progress in designing magnetic polymers.

Progress in designing magnetic polymers

As modern alcnemists, organic chemists keep trying to make plastics more like metals -- either to conduct electricity or to serve as magnets. Although several thought they had discovered magnetic organic materials, rarely have these leads panned out (SN: 4/18/87 p.252). However, in the March 27 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, three chemists at Caltech in Pasadena report developing a polymer with promising magnetic potential. Called PMPOT-18, it contains a hexagonal benzene-ring "tail" and a polyene backbone (see diagram).

To be magnetic, a material needs its unpaired electrons to align and spin in the same direction. This alignment, called ferromagnetic coupling, rarely occurs naturally because electrons tend to spin in opposite directions, cancelling out any potential ferromagnetism. But PMPOT-18's structure apparently encourages the necessary coupling. To generate unpaired electrons, Dennis A. Dougherty and two students removed an electron from several electron pairs in the backbone.

This provided magnetic properties in one dimension. "The problem is you need it to be three-dimensional to have a ferromagnet," says Dougherty. The molecules in the polymer also must line up to ensure coupling of electrons between, as well as within, the molecules. The researchers hope to use PMPOT-18's tail to help order the polymer molecules.
COPYRIGHT 1991 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1991, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Science News
Date:Apr 20, 1991
Words:209
Previous Article:Unmixing oil and water with microwaves.
Next Article:Squeeze on hydrogen reveals complexity.
Topics:


Related Articles
Pulling polymers into line.
Forging superstrong conducting polymers.
Better ceramics through biology.
Hot time for polymer magnet.
Dancing DNA: tripping the light fantastic with heredity's master molecules.
Materials with memory: the future's changing shape.
Polymer materials store data permanently.
Sweet frequency: implantable glucose sensor transmits data wirelessly.
Polymer science dean to retire.

Terms of use | Copyright © 2016 Farlex, Inc. | Feedback | For webmasters