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Four new multifunctional polymers (P1, P2, P3, and P4) containing EDOT units were synthesized by the Stille coupling reaction. A PL spectrum test found that the introduction of large conjugated groups led to strong fluorescence emission in all polymers. Among the electrochromic and switch properties, these polymer films exhibited reversible color changes, as well as good coloring efficiency. Electrochemical experiments found that the initial oxidation potentials of the polymers were 1.27 V, 1.67 V, 1.78 V, and 1.58 V, respectively. Among them, P3 showed a higher coloring efficiency (283.3 cm2·C−1), and P2 showed a shorter response time (tc = 2.2 s, tb = 2.8 s). These polymers all exhibited electrochromic and resistive switching storage characteristics. They have good solubility in many organic solvents. In the resistance switch memory characteristics, all polymers had obvious memristive properties, and P4 exhibited a larger switch current ratio (2527.42) and a smaller threshold voltage (0.9 V). [ABSTRACT FROM AUTHOR]

Based on the performance of improving the stabilities and coloring efficiencies of triphenylamine polymers, this paper separately synthesized different diamines and 3,4‐dimethylthieno[2,3‐b]thiophene‐2,5‐dicarboxylic acid, and the electrochromic functions of the polymer films were studied on indium‐tin oxide glass (ITO) glass. The polymers had a thiophene group, which was rich in π‐electrons and conducive to molecular stability, and showed good stabilities. Ultraviolet spectrum showed that all the six polymers had a wide absorption band in the neutral range of 200–700 nm. Electrochromic analysis showed that the six kinds of polymer films all showed reasonable optical contrast, short response time and low band gap in the infrared spectrum range of 200–1000 nm. Among them, the film formed by PAD2 on ITO glass had better electrochromic properties, longer bleaching response time (tc = 1.3 s, tb = 4.1 s), PAD3 had better coloration efficiency (214 cm2 C−1). [ABSTRACT FROM AUTHOR]

The development prospect of conductive electrochromic (EC) polymers requires the design of polymers with high performance and good stability. Here, a new scheme is designed to enhance EC properties by adjusting the monomer molecular structure. Four monomers with different structures based on thiophene and 3,4‐ethylenedioxythiophene (EDOT) are designed and synthesized. The corresponding polymer films (P1, P2, P3, and P4) are prepared by electrochemical polymerization at low applied potential. The spatial structure–performance relationship of precursors with different structures and polymers is systematically discussed. In the electropolymerization experiments, it is noted that P3 has no EC property. This may be connected to the spatial structure of P3 polymerization which is not suitable for charge transporting. By contrast, the other three polymers exhibit excellent electrochemical properties. The diffusion rate higher of P1 has also been corroborated by using electrochemical impedance spectroscopy (EIS) spectrum. The P1 film has the best stability and fastest colorized time among the samples; such superior electrochemical property may be associated with the closely stacked formed by the unique sheet‐like spatial structure. The design of the space structure has a significant impact on the optical and electrical properties of the polymer film. [ABSTRACT FROM AUTHOR]

Two donor units (D)‐acceptor units (A) type monomers were synthesized by Stille coupling reaction, and then three D‐A type hybrid polymers based on 3,4‐ethylenedioxythiophene and various benzodiazoles were synthesized by electrochemical polymerization. Spectroelectrochemical and kinetic studies of these polymers showed that all polymer films exhibited excellent electrochromic behavior, obvious optical contrast, and excellent stability. Among them, the response time of P3 film was the shortest (tc = 1.6 s, tb = 2.2 s), the coloring efficiency of P2 film was the highest (CE = 333 cm2·C−1), and the stability of P1 was the best (the ΔT loss of P1 after 1000 s cycles is only 2.3%). Therefore, these data prove that these new polymers have great potential in applications as electrochromic materials. [ABSTRACT FROM AUTHOR]

Bredereck oxazole synthesis was utilized to create a series of novel D-A polymers based on the triphenylamine (TPA) derivative, 4,4′-Diformyltriphenylamine (DPA), 4,4′-((4-bromophenyl)azanediyl)dibenzaldehyde (BPA), and oxamide/dithiooxamide. The obtained novel polymers exhibited impressive solution processabilities and excellent thermal stabilities. In the entire processes of electrochemical oxidation, these polymer films exhibited excellent electrochromic (EC) performances, high optical contrasts (49.6–52.8 %), high coloration efficiencies (362–451 cm2·C−1), and excellent cycling stabilities (18.6–33.9 % decay) with a cycle time of 20 s. By applying voltage, electrofluorochromic (EFC) performance can also be adjusted. Furthermore, these polymers showed fluorescence (PL) in solvents and solvatochromic effects in absorption. The outcome was indicative of the addition of oxazole[5,4- d ]oxazoles (OzOz) and thiazolo[5,4- d ]thiazoles (TzTz), whose highly conjugate rigid planar structures can significantly increase molecule stabilities and minimizing volume shrinking during charge transfer. In addition, due to introducing bromine atoms, the p-π conjugations enhanced the conjugation degrees of the molecules, which facilitated the electron transfers. Experimental results show that these improvement schemes will pave a way for obtaining multi-function optoelectronic devices with long-term cyclic stabilities. [Display omitted] • The electrochromic stability was optimized by introducing TzTz-type/OzOz-type group to the polymers. • Polymers were synthesized using fewer steps and cheap raw materials. • The introduction of fluorescent chromophore the fluorescence properties of the polymer and increased their potential purposes. [ABSTRACT FROM AUTHOR]

• A series of novel conjugated polymers containing benzo[ c ][1,2,5]thiadiazole groups and triphenylamine units were synthesized. • The polymer films exhibited reasonable electrochromic features. • The TPABTD-b film exhibited high coloration efficiency (CE) 270 cm2 C-1. Six novel electrochromic (EC) polymers containing triphenylamine units and benzo[ c ][1,2,5]thiadiazole (BTD) units, coded as TPABTA, TPABTD, TPABTD-a, TPABTD-b, TPABTD-c and TPABTD-d, were successfully synthesized through polymer condensation reaction and their electrochromic properties were characterized in detail. The films of these polymers exhibited reversible color changes, high optical transparency, good solubility in many organic solvents and good coloration efficiency. Among them, the TPABTD-b film showed a set of reasonable electrochromic features, including high coloration efficiency (270 cm2·C-1), appropriate transmittance change (23 % at 849 nm) and a relatively longer response time in bleaching process (t b = 3.7 s). [ABSTRACT FROM AUTHOR]

In this study, six polyschiff bases (PSBs) were created by reacting 2,5-di(pyridin-4-yl)terephthalaldehyde with four artificial diamine monomers. All six polymers demonstrated excellent solubility in typical solvents and notable color variations in the domain of electrochromic characteristics. After blocking, polymer films had good coloration efficiencies, with the highest polymer P5 having a coloration efficiency of 289 cm2 C−1. The block polymers also respond faster, with P5 having the quickest bleaching time (2.8s) and P6 having the quickest coloration time (1.1s). After 1000 s of cycling, all six polymers displayed good cycling stabilities and minimal losses. Moreover, Three photodetector devices based on blocked polymers had been produced. The experimental results showed that the three photodetectors had good specific detectivities and high gains. These characteristics suggested that the blocked polymers would be suitable candidates for use as electrochromic and photodetector electrode materials. [Display omitted] • Six novel polyschiff bases used in electrochromic and photodetectors. • Post-blocking polymer P5 showed high coloration efficiency of 289 cm2 C−1. • Three photodetector devices displayed good specific detectivities and high gains. [ABSTRACT FROM AUTHOR]