Tuning of electrochromic properties by copolymerization of monoalkoxythiophenes and dialkoxythiophenes

Monoalkoxysubstituted and dialkoxysubstitued thiophene monomers were synthesized by the nucleophilic substitution and transetherification reactions. Electrochemical homopolymerization of 3-octyloxythiophene (OOT) and 3,4-dioctyloxythiophene (DOOT), copolymerization of OOT with DOOT were performed via potentiodynamic and potentiostatic methods in the supporting electrolyte. Both the copolymer and homopolymers were characterized via cyclic voltammetry, scanning electron microscopy, gel permeation chromatography, and spectroelectrochemical analysis. In the redox process of the polymers, it was linear relationship between the peak current and the scanning rate in their cyclic voltammograms. The copolymer of P(OOT-co-DOOT) showed obvious change of color between red and bright blue in reduced and oxidized states, that has a great difference with the homopolymers. The morphology studies indicated that the electrochemical deposition of P(OOT-co-DOOT) proceeds via a mechanism of nucleation and two-dimensional growth. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012