Electrochromic Polymers

Abstract An electrochromic material is one where a reversible color change takes place upon reduction (gain of electrons) or oxidation (loss of electrons), on passage of electrical current after the application of an appropriate electrode potential. In this article the general field of electrochromism is introduced, with coverage of the types, applications, and chemical classes of electrochromic materials and the experimental methods that are used in their study. The main classes of electrochromic polymers are then surveyed, with descriptions of representative examples of electrochromic polymers based on transition metal coordination complexes, polymeric viologen systems, and conducting polymers.