Synthesis and characterization of novel electrochromic devices derived from redox-active polyamide–TiO2 hybrids

Abstract

Two novel electrochromic (EC) polyamides with functional hydroxyl groups were successfully synthesized for preparing homogeneous hybrid films. The hydroxyl groups in the repeating units of the polymer backbones could serve as active sites in the sol–gel reaction to obtain organic–inorganic nanocomposites comprising titanium dioxide (TiO₂) and anodic EC polyamides (TPPA-OH PA and TPB-OH PA). By using the facile approach of an electron donor–acceptor hybrid system in this report, the EC response capability could be essentially enhanced during the colouring and bleaching process. In addition, the colouring contrast and electrochemical stability of the fabricated EC devices could be further increased by judiciously combining the complementary EC material of heptyl viologen (HV) and TiO₂.