Electrosynthesis of Aromatic Poly(amide-amine) Films from Triphenylamine-Based Electroactive Compounds for Electrochromic Applications

Two electropolymerizable monomers with a methoxytriphenylamine core linked via amide groups to two triphenylamine (TPA) or N-phenylcarbazole (NPC) terminal groups, namely 4,4′-bis(4-diphenylaminobenzamido)-4′ ′-methoxytriphenylamine (MeOTPA-(TPA)2) and 4,4′-bis(4-(carbazol-9-yl)benzamido)-4′ ′-methoxytriphenylamine (MeOTPA-(NPC)2), were synthesized and characterized by FTIR and 1H NMR spectroscopy, mass spectrometry, and cyclic voltammetry. The electrochemical polymerization reactions of these MeOTPA-cored monomers over indium tin oxide (ITO) electrode allow the generation of electroactive poly(amide-amine) films. The electro-generated polymer films exhibited reversible redox processes and multi-colored electrochromic behaviors upon electro-oxidation, together with moderate coloration efficiency and cycling stability. The optical density changes (∆OD) were observed in the range of 0.18–0.68 at specific absorption maxima, with the calculated coloration efficiencies of 42–123 cm2/C. Single-layer electrochromic devices using the electrodeposited polymer films as active layers were fabricated for the preliminary investigation of their electrochromic applications.