Conducting polymer as electrochromic material: polyaniline

The first conducting polymer was reported in 1977 when Shirakawa, MacDiarmid, Heeger and other coworkers1 discovered that polyacetylene (Fig. 1), an organic polymer and electrical insulator, could be converted into an electrical conductor by absorbing a small amount of iodine. Since then, active research has led to the synthesis of new conducting polymers. Examples are: polyphenylene2, polypyrrole3, polythiophene4, poly-(phenylenesulfide)2 and polyaniline5. Their chemical structures are shown in Fig. 1.