Synthesis and Characterization of Electrochromic Polyamides with Well‐Defined Molecular Structures and Redox Properties

Abstract

In this paper we report the synthesis and characterization of a series of electrochromic polyamides (alternating copolymers). The synthesis proceeds via the condensation polymerization between amine‐capped oligoaniline and acyl chlorides such as isophthaloyl dichloride, terephthaloyl chloride, azelaoyl chloride, and dodecanedioyl dichloride. Both the orthogonal tert‐butoxycarbonyl (BOC) group on the oligoaniline segment and the non‐conjugated aromatic or aliphatic segment on the polymer backbone play a vital role in the formation of the final polyamides with good solubility in common organic solvents. We cast thin polyamide films from their chloroform solutions and studied their electrochemical behavior and spectroscopic properties. In contrast to the polyaniline, the copolymers bearing oligoaniline segments show four distinct oxidation states, which were fully characterized using IR and UV‐vis spectroscopy. The copolymer thin films also exhibit electrochromic behavior when a linear potential sweep is applied. Compared with the polyaniline, the polyamides adhere much more strongly to the indium tin oxide (ITO) coated glass and show no signs of delamination after hundreds of redox cycles in a hydrochloric acid solution. We believe that these factors make these novel polyamides very attractive as electrochromic materials.

Synthesis, characterization, and redox and electrochromic behaviors of poly(3‐n‐octyloxythiophene)

“…Electrochromic materials have extensive applied prospects as intelligent materials and have been used for some devices. [1][2][3] In recent years, transition-metal oxides (e.g., WO 3 4,5 ), small organic molecules (e.g., viologen 6,7 ), some conducting polymers [e.g., Polypyrroles (PPys), 8 polyanilines, 9,10 and polythiophenes [11][12][13] have been intensively investigated for their electrochromic properties.…”

Design, synthesis and characterization of novel electroactive polyamide with amine‐capped aniline pentamer in the main chain via oxidative coupling polymerization

“…5) of the polyamide showed three pairs of redox peaks, different from polyaniline who has a typical two pairs of redox peaks (350 mV and 800 mV). 12 We consider that the first oxidation wave at around 300 mV corresponds to the transition from the leucoemeraldine oxidation state to the first emeraldine oxidation state, and the second oxidation wave at around 500 mV is assigned to the transition from the first emeraldine oxidation state to the second emeraldine oxidation state and the last oxidation wave at around 700 mV is due to the transition from the second emeraldine oxidation state to the pernigraniline oxidation state (Fig. 6).…”

“…Zhu et al 11 prepared a novel polymer with tetra-aniline and phenylene sulfide segments in the main chain as repeat unit, which displayed good solubility in most common organic solvents such as THF, DMSO, and DMF and its electrical conductivity could be up to 100 S cm À1 upon preliminarily protonicdoping. Gao et al 12 reported the introduction of the oligoaniline units into the main chain of the polyamides. In our present work, a novel approach of oxidative coupling polymerization to synthesize electroactive copolymers is developed, 13 which started with the macromonomer of oligoaniline and p-phenylenediamine.…”

Oligoaniline-containing electrochromic polymers with tunable properties

“…Therefore, oligoanilines have recently been used as an electroactive unit for the preparation of electrochromic polymers. So far, many oligoaniline-containing electrochromic polymers have been designed and synthesized [16][17][18][19] through two strategies: (1) direct polymerization of oligoanilinefunctionalized monomers, and (2) post-functionalization of existing polymers using oligoaniline groups. In our group, some additional functional groups, such as azobenzene, sulfoacid, and alkene, were also involved in the oligoaniline-containing polymers to improve their electrochromic properties, including color range, switching time, and stability [20][21][22].…”