Polymer, Vol.116, 89-98, 2017
Optically transparent polyamides bearing phenoxyl, diphenylamine and fluorene units with high-contrast of electrochromic and electrofluorescent behaviors
Two kinds of new electroactive polyamides were synthesized from a novel diphenylamine-fluorene skeleton bis(ether amine) monomer "N, N-bis((4-aminophenoxy) phenyl)-2-amino-9,9-dimethylfluorene" with cycloaliphatic and aromatic dicarboxylic acids, respectively. These polyamides were highly soluble in many organic solvents and could be solution-cast into transparent and flexible films. These films were nearly colorless with the optical transmittance over 90% at 450 nm and the cutoff wavelengths in the range of 385-390 nm. These polyamides revealed reversible redox with a strong color changing from colorless (neutral state) to green (oxidation state), and the electrochromic contrast of transmittance was up to 86% at 410 nm. Especially, the polyamide derived from cycloaliphatic acid exhibited strong blue fluorescence emission with the quantum yield up to 14.5% and 58.9% in solid state and solution state, respectively. Furthermore, the fluorescence of the polyamide film could be reversibly and readily modulated by electrochemical redox exhibiting a high contrast of 83. (C) 2017 Elsevier Ltd. All rights reserved.