Phase engineering for enhanced electrochromism in conjugated polymers

Development of nanostructured blends of electrochromic polymers formed by s elf-assembly is reported. We have prepared blends of a polythiophene deriva tive. poly(3,4-ethylenedioxythiophene) and polypyrrole, combining optical a nd electrochemical properties of the two polymers. The route towards these blends is based on self-assembly of the former polymer into a hydrogel, and subsequent electrochemical polymerisation of the latter using the conducti ng hydrogel matrix as a template. When used as electrodes, these materials show very fast electrochromic response. The route used in the present work is generic and may be extended to other polymers. (C) 2001 Elsevier Science Ltd. All rights reserved.