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This study explores the modeling, design, simulation, and testing of a new composite material designed for high-strength and high-temperature resistance in in-space optical mining, examining its properties at both the polymer and atomic/molecular levels. At the polymer level, the investigation includes mechanical and thermal performance analyses using COMSOL Multiphysics 6.1, employing layerwise theory, equivalent single layer (ESL) theory, and a multiple-model approach for mechanical modeling, alongside virtual thermal experiments simulating laser heating. Experimentally, porous Polyaniline (PANI) films are fabricated via electrochemical polymerization, with variations in voltage and deposition time, to study their morphology, optical performance, and electrochemical behavior. At the atomic and molecular levels, this study involves modeling the composite material, composed of Nomex, Kevlar, and Spirooxazine-Doped PANI, and simulating its behavior. The significance of this work lies in developing a novel composite material for in-space optical mining, integrating it into optical mining systems, and introducing innovative thermal management solutions, which contribute to future space exploration by improving resource efficiency and sustainability, while also enhancing the understanding of PANI film properties for in-space applications. [ABSTRACT FROM AUTHOR]

Phenazine-based redox-active centers are capable of averting chemical bond rearrangements by coupling during the reaction process, leading to enhanced stabilization of the material. When introduced into a high-performance polymer with excellent physicochemical properties, they can be endowed with electrochemical properties and related prospective applications while maintaining the capabilities of the materials. In this study, a facile C-N coupling method was chosen for the synthesis of serial poly(aryl ether sulfone) materials containing phenazine-based redox-active centers and to explore their electrochemical properties. As expected, the cyclic voltammetry curves of PAS-DPPZ-60, which basically overlap after thousands of cycles, indicate the stability of the electrochemical properties. As an electrochromic material, the transmittance change in PAS-DPPZ-60 exhibits only a slight attenuation after as long as 600 cycles. Meanwhile, as an organic battery cathode material, PAS-DPPZ has a theoretical specific capacity of 126 mAh g−1, and the capacity retention rate is 82.6% after 100 cycles at a 0.1 C current density. The perfect combination of advantageous features between phenazine and poly(aryl ether sulfone) is considered to be the reason for the favorable electrochemical performance of the material series. [ABSTRACT FROM AUTHOR]

Owing to low‐power, fast and highly adaptive operability, as well as scalability, electrochemical random‐access memory (ECRAM) technology is one of the most promising approaches for neuromorphic computing based on artificial neural networks. Despite recent advances, practical implementation of ECRAMs remains challenging due to several limitations including high write noise, asymmetric weight updates, and insufficient dynamic ranges. Here, inspired by similarities in structural and functional requirements between electrochromic devices and ECRAMs, high‐performance, single‐transistor and neuromorphic devices based on electrochromic polymers (ECPs) are demonstrated. To effectively translate electrochromism into electrochemical ion memory in polymers, this study systematically investigates polymer–ion interactions, redox activity, mixed ionic–electronic conduction, and stability of ECPs both experimentally and computationally using select electrolytes. The best‐performing ECP‐electrolyte combination is then implemented into an ECRAM device to further explore synaptic plasticity behaviors. The resulting ECRAM exhibits high linearity and symmetric conductance modulation, high dynamic range (≈1 mS or ≈6x), and high training accuracy (>84% within five training cycles on a standard image recognition dataset), comparable to existing state‐of‐the‐art ECRAMs. This study offers a promising approach to discover and design novel polymer materials for organic ECRAMs and demonstrates potential applications, taking advantage of mature knowledge basis on electrochromic materials and devices. [ABSTRACT FROM AUTHOR]

We have assessed new anodic coloring materials that can be used as ion storage layers in complementary energy storage electrochromic devices (ESECDs) to enhance their electrochromic storage performance. In our study, we fabricated counter electrodes (ion storage layers) using an IrO2-doping NiO (Ir:NiO) film through cathodic arc plasma (CAP) with varying surface charge capacities. We have also investigated the influence of a MoO3-doped WO3 (Mo:WO3) film using various Ar/O2 gas flow ratios (1/4, 1/5, and 1/6, respectively). The ESECDs used in the demonstration were 10 × 10 cm2 in size and achieved an optical transmittance modulation of the Ir:NiO ESECDs (glass/ITO/ Mo:WO3/gel polymer electrolytes/ Ir:NiO/ITO/glass), with ΔT = 53.3% (from Tbleaching (66.6%) to Tcoloration (13.1%)). The ESECDs had a quick coloration time of 3.58 s, a rapid bleaching time of 1.24 s, and a high cycling durability. Furthermore, it remained at a 45% transmittance modulation level even after 3000 cycles. New anodic materials can thereby provide an alternative to traditional active materials for bi-functional electrochromic batteries. [ABSTRACT FROM AUTHOR]

The molecular engineering of conjugated systems has proven to be an effective method for understanding structure–property relationships toward the advancement of optoelectronic properties and biosensing characteristics. Herein, a series of three thieno[3,4-c]pyrrole-4,6-dione (TPD)-based conjugated monomers, modified with electron-rich selenophene, 3,4-ethylenedioxythiophene (EDOT), or both building blocks (Se-TPD, EDOT-TPD, and EDOT-Se-TPD), were synthesized using Stille cross-coupling and electrochemically polymerized, and their electrochromic properties and applications in a glucose biosensing platform were explored. The influence of structural modification on electrochemical, electronic, optical, and biosensing properties was systematically investigated. The results showed that the cyclic voltammograms of EDOT-containing materials displayed a high charge capacity over a wide range of scan rates representing a quick charge propagation, making them appropriate materials for high-performance supercapacitor devices. UV-Vis studies revealed that EDOT-based materials presented wide-range absorptions, and thus low optical band gaps. These two EDOT-modified materials also exhibited superior optical contrasts and fast switching times, and further displayed multi-color properties in their neutral and fully oxidized states, enabling them to be promising materials for constructing advanced electrochromic devices. In the context of biosensing applications, a selenophene-containing polymer showed markedly lower performance, specifically in signal intensity and stability, which was attributed to the improper localization of biomolecules on the polymer surface. Overall, we demonstrated that relatively small changes in the structure had a significant impact on both optoelectronic and biosensing properties for TPD-based donor–acceptor polymers. [ABSTRACT FROM AUTHOR]

Four novel isoindigo–thiophene D–A–D–type precursors are synthesized by Stille coupling and electrosynthesized to yield corresponding hybrid polymers with favorable electrochemical and electrochromic performances. Intrinsic structure–property relationships of precursors and corresponding polymers, including surface morphology, band gaps, electrochemical properties, and electrochromic behaviors, are systematically investigated. The resultant isoindigo–thiophene D–A–D–type polymer combines the merits of isoindigo and polythiophene, including the excellent stability of isoindigo–based polymers and the extraordinary electrochromic stability of polythiophene. The low onset oxidation potential of precursors ranges from 1.10 to 1.15 V vs. Ag/AgCl, contributing to the electrodeposition of high–quality polymer films. Further kinetic studies illustrate that isoindigo–thiophene D–A–D–type polymers possess favorable electrochromic performances, including high optical contrast (53%, 1000 nm), fast switching time (0.8 s), and high coloration efficiency (124 cm2 C−1). These features of isoindigo–thiophene D–A–D–type conjugated polymers could provide a possibility for rational design and application as electrochromic materials. [ABSTRACT FROM AUTHOR]

In this study, a new copolymer, which is a combination of two chemical structure (9,10-di(furan-2-yl)anthracene and 3,4-ethylenedioxythiophene was synthesized via electrochemical synthesis methods in the electrolyte medium of 0.1 M TBAPF6/ACN solution. PEDOT homopolymer was also electrosynthesized for comparator experiments of the polymer formations in the same medium. The characterizations of polymers were achieved with general optical and electrochemical characterization techniques. The corresponding electrochromic copolymer shows blue and lilac color in its neutral and oxidized states, respectively. The copolymer has an optical band gap of 1.65 eV and 24% optical contrast at 500 nm with a high coloration efficiency (170 cm2/C) and a fast switching time (1.0 s). [ABSTRACT FROM AUTHOR]

Pursuing to develop novel polymer-based electrode materials and explore their performance in electrochromic capacitive windows (ECWs), three polyamides containing propylenedioxythiophene (ProDOT) units were synthesized. The polymers were processed into thin coatings and subjected to rigorous structural and photophysical characterization, with focus on the electrochromic response and energy storage capability. One of the polymers showed electrochromic response with ultrafast color change (0.8 s for coloring) from highly transmissive yellow to deep green, opposite to most ProDOT-based materials that exhibit bleaching trends during oxidation, which is more convenient for smart glazing. A coloration efficiency of 358 cm2 × C−1, a maximum CE decay of 2.6 % after 100 cycles, and an excellent electrochromic stability, even up to 500 cycles was achieved for this material. In three-electrode cell configuration, this polymer revealed practical energy storage properties, including a wide voltage window, a good capacitance, of 5.63 mF × cm−2, and an outstanding electrochemical cycling durability. Therefore, a prototype polyamide based-ECW device was built and its overall performance was explored. Due to the well capability of this polymer to simultaneously operate as a smart color changing and energy storage electrode, it can be considered as promising material for use in energy storage smart windows with potential applications in green-enabling technologies. • Three polyamides containing propylenedioxythiophene (ProDOT) units are synthesized. • The polymers display thermal stability up to 270 °C and CT blue/green fluorescence. • The polymers containing only ProDOT provide low capacitance and no electrochromism. • TPA- and ProDOT-based polyamide undergoes ultrafast color switch while stores energy. • An ECW is realized enabling smart monitoring of the energy level stored in the device. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Doping plays an essential role in the properties of conducting polymers. Film thickness not only has a direct influence on their photoelectric properties, but also affects the doping ability, which may lead to the decline of capacitance and electrochromic properties caused by incomplete doping. Therefore, it is essential to study the quantitative relationship between doping level and film thickness in application. Herein, empirical formula between doping level and thickness was obtained by studying the spectroelectrochemistry behaviors of two different electrochromic materials, poly(N,N'‐bis(3,5‐(2‐thienyl)‐phenyl)‐1,6,7,12‐tetrachloroperylene‐3,4,9,10‐perylenetetracarboxylic diimide) (poly(Th‐Cl‐PBI)) and poly(3,4‐ethylenedioxythiophene) (PEDOT). The doping level is verified to be correlated to the reciprocal of the 3rd power of film thickness. Experimental results fit these formulas very well, giving correlation coefficient R2 higher than 0.99. The optical contrast prediction of these two electrochromic materials is also used to verify this relationship formula. For the first time, we quantitatively connect these two important parameters of conducting polymers, doping level and thickness. [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]

Due to its high electronegativity and small atomic radius without undesirable steric hindrance, the incorporation of fluorine atoms into the benzene unit which started from the commercially available compounds is a feasible way to tune the energy levels of polymers, and its electrochromic application is expected to achieve a new breakthrough. Herein, in this paper, benzene units with different fluorine atom numbers were selected as the core and 3,4-ethylenedioxythiophene (EDOT) as the terminal unit, three fluorinated electrochromic precursors (FPh-EDOT, 2FPh-EDOT, and 4FPh-EDOT) were designed and synthesized by Stille coupling reaction, and the corresponding fluorinated π-conjugated electrochromic polymers (P(FPh-EDOT), P(2Ph-EDOT), and P(4FPh-EDOT)) were prepared by electrochemical polymerization method. The effects of different fluorinated benzene units on the photophysics, electrochemistry, and electrochromic properties of precursors and polymers were systematically investigated, and the structure-property relationship was further revealed. All of them have low initial oxidation potentials {FPh-EDOT (0.65 V), 2FPh-EDOT (0.72 V), and 4FPh-EDOT (0.70 V)}, which makes it easy to obtain high-quality new fluorinated polymers at low polymerization potential. With the increase of the number of F atoms, the UV–vis absorption spectra and emission spectra of fluorinated monomer firstly red-shifted and then blue-shifted. The corresponding fluorinated polymers have good electrochemical activity and stability (the P(2Ph-EDOT) activity remained 82.7% after 500 cycles), making it possible to realize their electrochromic devices. All these three fluorinated polymers show obvious color change from the neutral state to the fully oxidized state (P(FPh-EDOT) changes from brown to grayish blue, P(2FPh-EDOT) changes from brown to gray, and P(4FPh-EDOT) changes from dark blue to light blue). The kinetic study further shows that all of them have distinguish electrochromic properties with good optical stability, very short response time (0.9 s for P(2FPh-EDOT) at 700 nm), and favorable coloration efficiency (130.7 cm2 C−1 for P(FPh-EDOT) at 503 nm). Overall, all these three fluorinated polymers have low optical band gap, good redox stability and electrochromic properties, are very promising electrochromic materials, which is worthy for the further research and development. [Display omitted] • Three fluorinated benzene-based electrochromic precursors were synthesized. • All of the fluorinated precursors have low initial oxidation potentials. • With the increasednumber of F atoms, optoelectronic performances of the fluorinated precursors and polymers was tuned. • The fluorinated polymers have good redox activity and stability, and obvious color change. • All fluorinated polymers are promising electrochromic materials due to their distinguish electrochromic properties. [ABSTRACT FROM AUTHOR]

Chlorination has proved to be an efficient method in tuning energy levels and optoelectronic properties of organic semiconducting materials with cheaper synthesis and low-cost raw materials when compared with the fluorinated analogues. Herein, in this work, 5-chlorobenzo[c][1,2,5]thiadizole (Cl-BT) unit was chosen as a new acceptor unit to design two new D-A type electrochromic conjugated polymer: P(Cl-T) and P(Cl-EDOT). The electrochemical behavior and electrochromic performances of above-mentioned chlorinated polymers were studied by electrochemical polymerization techniques and spectroelectrochemistry. Thanks to the strong electron-withdrawing ability of Cl-BT unit and the strong electron-donating properties of EDOT unit, the resultant Cl-EDOT precursor could electropolymerize into high quality hybrid polymer films at lower potential (0.71 V vs. Ag/AgCl) with favorable redox activity and better redox stability. Spectroelectrochemistry shown that as-formed lower band gaps P(Cl-EDOT) exhibits reversible color-changing nature from pale blue to gray accompanied with the moderate optical contrast (13.9%), fast response time (0.6 s), and favorable coloration efficiency (126.4 cm2 C−1) in the NIR region that was measured from the kinetic studies. By optimizing the tested electrolyte and solution, its electrochromic performance is further improved (optical contrast: 25.6%, response time: 0.25 s, coloration efficiency: 275.9 C−1 cm2). The favorable redox stability and electrochromic performance of P(Cl-EDOT) make it a good candidate to construct electrochromic device, and Cl-BT unit should be a promising building block in designing high performance near infrared electrochromic materials. [Display omitted] • Two electrochromic precursor based on 5-chlorobenzo[c][1,2,5]thiadizole unit were synthesized by Stille coupling reaction. • Different donor brings different influence on the photophysical properties of the chlorinated precursors and its polymers. • The introduction of EDOT unit is beneficial for the preparation of better-quality chlorinated polymers. • P(Cl-EDOT) exhibit better redox activity and stability, and satisfied electrochromic performances. • Chlorinated benzothiadiazole could be a promising building blocks in constructing high performance D-A conjugated polymers. [ABSTRACT FROM AUTHOR]

Three novel triphenylamine-based compounds with arylene-vinylene, or mixed arylene (cyano)vinylene-ethynylene moieties in a star-shaped configuration, have been synthesized and used to electrogenerate smart polymers coatings able to sense harmful nitroaromatic derivatives and to provide chromic response to an applied voltage. The introduction of different π-spacers between triphenylamine units led to oligomers with variable structures, which were validated by NMR, FT-IR, and MALDI-TOF analyses. The detailed study of their photophysical and electrochemical characteristics revealed some intriguing structure-properties correlations. Due to the presence of the peripheral TPA units, the electropolymerization of oligomers generated thin films exhibiting distinct colours and morphologies. Their supramolecular arrangements in granular or tubular assemblies were notably influenced by the initial oligomeric structures. The donor-acceptor polymer containing arylene-(cyano)vinylene-ethynylene moieties displayed reversible and stable multicolour switches, and a very good coloration efficiency, while the polymer containing only arylene-vinylene π-spacers behaved as an efficient sensor towards trinitrophenol, with a highest detection limit of 25 μM. Overall data obtained in this study demonstrates the potential of electrogenerated polymers derived from TPA-based star-shaped oligomers to behave not only as intelligent electrochromic materials but also as promising receptors for nitroaromatic derivatives through electrochemical detection, indicating their perspective applications in nowadays fields. [Display omitted] • Three novel triphenylamine-based star-shaped oligomers were synthesized through a convergent approach. • The influence of the internal π-spacer on the photophysical and morphological characteristics was assessed. • Electrogenerated polymer coatings displayed efficient electrochromic responses. • Polymers derived from star-shaped oligomers showed promise for TNP derivative detection. [ABSTRACT FROM AUTHOR]

Thiadiazolobenzotriazole (TBZ)‐containing donor‐acceptor (D–A) type polymers are rarely investigated as electrochromic materials, although they have made important progress in the fields of organic transistors and solar cells. In this work, a new class of soluble D–A type electrochromic polymer is designed using the alkyl substituted TBZ units as the acceptor, the alkyl substituted 3,4‐propylenedioxythiophene (ProDOT) units as the donor, and benzene (B) units as the π‐bridge. Through altering the molar ratio of ProDOT/B/TBZ, three polymers named PPBT‐1, PPBT‐2 and PPBT‐3 are chemically synthesized. After various characterizations, it is found that all the polymers display saturated green in their neutral states and switch to transparent gray upon oxidation with narrow optical bandgaps, and moreover, they demonstrate high optical contrast, rapid switching speed, and excellent coloration efficiency particularly in the near infrared region. The impacts of different donor‐acceptor feed ratios on electrochromic performances are mainly reflected in the optical, electrochemical and kinetic properties. In contrast to PPBT‐1 and PPBT‐3, PPBT‐2 show the best performances with the most appropriate ProDOT/B/TBZ ratio of 2/3/1 in its backbone. These positive results provide a theoretical basis for the research of electrochromic polymers based on TBZ units. [ABSTRACT FROM AUTHOR]

In comparison with traditional inorganic electrochromic materials, organic polymers offer advantages such as fast switching speed, flexibility, lightweightness, low cost and nontoxicity, solution‐processability, and color tunability. Herein, a series of hyper‐branched copolymers are synthesized from triphenylamine and 3,4‐ethylenedioxythiophene with different feed ratios via iron(III) chloride (FeCl3)‐mediated oxidative polymerization. The resultant organic‐soluble polymers are easily processable and their corresponding electrochromic devices are found to be stable with limited degradation upon 2500 cycles. In addition to their facile synthesis to achieve solution‐processable polymers, studies also show that the polymers exhibit multielectrochromic properties and give rise to five colored states upon oxidative‐doping by applying an external voltage between 0 and 2.0 V, providing an interesting example of polymers with unique electrochromic switching among up to five colors, from yellow at the neutral state, to pale green, pale purple, orange, and finally gray. [ABSTRACT FROM AUTHOR]

This mini review investigates the relationship and interactions of polymers under an applied electric field (AEF) for sensor applications. Understanding how and why polymers are reoriented and manipulated under an AEF is essential for future growth in polymer-based electrochemical sensors. Examples of polymers that can be manipulated in an AEF for sensor applications are provided. Current methods of monitoring polymer reorientation will be described, but new techniques are needed to characterize polymer response to various AEF stimuli. The unique and reproducible stimuli response of polymers elicited by an AEF has significant potential for growth in the sensing community. [ABSTRACT FROM AUTHOR]

Two donor-acceptor electrochromic copolymers containing fused rigid units of cyclopentadithiophene and diketopyrrolopyrrole, namely PCPDTT-DPP with benzene and thiophene ring linkers, were successfully synthesized. The electrochromic properties of the copolymers were characterized by cyclic voltammetry, UV-Vis spectroscopy and spectroelectrochemical method. The results demonstrated that the effect of DPP on the copolymer showed the p-type doping with an electrochemical band gap of 1.45 eV. The copolymer showed a higher color contrast changing from purple to transparent with %ΔT of 55% at ±1.0 V vs. Ag/AgCl compared to the parent polymer containing only cyclopentadithiophene unit. The results indicated that the new copolymer could be a potential candidate for electrochromic materials in smart films and windows. [ABSTRACT FROM AUTHOR]

[Display omitted] • A soluble conjugated polymer with reversible change from yellow to light green. • The polymer shows ultrafast coloring time (0.21 s) and a high coloring efficiency. • The polymer can be used as a ion detection to detect Fe3+ with a low detection limit. • Such soluble conjugated polymers are reported firstly to detect Ru3+ (8.07 μM). The design of soluble electrochromic materials with fast responsivity for use in flexible displays and electronic papers remains a challenge. Most of the materials explored properties such as excellent contrast and rich color variation, while fast responsivity is also one of the key properties, which together push electrochromic materials into everyday life. Here we report a soluble electron conjugated polymer PDT-BTz, i.e., poly[3,3-dimethyl-3,4-dihydro-2H-thieno[3,4-b] [1,4] dioxepine-alt-(2-(heptan-3-yl)benzo[d]thiazole], which was designed to be highly redox active polymeric backbone for electrochromism and constructed to engineer with chelating sites for metal ion detection, via direct (hetero)arylation polymerization of 3, 4-propenyldioxythiophene with benzothiazole derivative. The resultant PDT-BTz exhibited a pair of distinct redox peaks in the range of 0.41–––1.20 V, corresponding to a clear color change in the visible region between yellow and light green as revealed by cyclic voltammetry. PDT-BTz is easily casted into thin film and is highly responsive to visible light to achieve a very short response time of only 0.21 s, which is much far superior to other polymers reported so far. Remarkably, this electrochromic PDT-BTz is highly luminescent and enables to selectively detect iron Fe (III) and Ru (III) ions, via built-in C–S and C = N chelating units, with exceptional rate constants and detection limits. Together with the high thermal stability, the electron polymer opens a way to a novel class of soluble conjugated polymer that can merge dual functions of electrochromism with ion detection capability into one material. [ABSTRACT FROM AUTHOR]

• Conjugation break spacers induced soluble quaterthiophene ECPs. • 4TBC and 4TCSIB can switch from the yellow to green series. • New color complementary strategy to assemble DPECDs. • Optional IS layers endow rich colors for adaptive camouflage ECD-1 and ECD-2. • ECD-12 can switch freely between eighteen modes for multiple environments. The potential for electrochromic materials/devices to be utilized as adaptive camouflage for multiple environments remains to be investigated. In this work, the solution processible electrochromic polymers 4TBC and 4TCSIB were constructed using quaterthiophene as the basic electrochromic unit and tetraphenylsilane/meta benzene units as the conjugation break spacers. Taking advantage of the well-defined redox behavior of quaterthiophene, both polymers can switch from yellow to green series. In particular, 4TBC has better electrochromic performance, including high optical contrast and available cycle stability. Furthermore, the color-complementary polymer pEKE and pEBE were selected as the optional ion storage layer to design and construct dual polymer electrochromic adaptive camouflage devices. The electrochromic device-1 (ECD-1 (4TBC-pEKE)) and electrochromic device-2 (ECD-2 (4TBC-pEBE)) can switch from diverse yellow to different green at an operating voltage of −0.3 V ∼ 1.2 V. Most importantly, we introduce the ECD-12 , which integrates ECD-1 and ECD-2 , can realize multiple modes (up to eighteen modes) conversion, and is expected to be applied to savanna, mountain and multiple environments. This work proposes an existing generic strategy of optional ion storage layers for constructing dual polymer electrochromic devices toward multiple environments adaptive camouflage. [ABSTRACT FROM AUTHOR]

Tetraphenylethylene (TPE) can improve nature-state transmittance and response time when used as a building block in electrochromism. Two precursors of TPE-based molecules (TPE‐2T and TPE-2E) were successfully synthesized by Stille coupling reaction, and electropolymerized to yield the corresponding polymers of P(TPE‐2T) and P(TPE-2E). Characterizations of the above polymers were performed by cyclic voltammetry (CV), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Furthermore, the spectroelectrochemistry and electrochromic properties of P(TPE‐2T) and P(TPE-2E) were compared investigated. P(TPE‐2T) demonstrated yellow in the neutral state to deep green in the oxidized state while P(TPE-2E) showed colorless-to-violet color changes with 0–1.4 V. P(TPE‐2T) displayed much better electrochromic performance due to its electroactivity with moderate optical contrast (32%) and fast response time (0.9 s). However, P(TPE-2E) showed low optical contrast, which is in agreement with the spectroelectrochemistry result (only slight wavelength shift between the neutral state and the oxidized state). From these results, P(TPE‐2T) can be further explored electrochromic material towards indoor electrochromic product and flexible display. • Tetraphenylethylene-based ECPs (P(TPE-2 T) and P(TPE-2E)) were designed and synthesized. • P(TPE-2 T) exhibited better thermal stability, crystallization performance, and improved electrochromic performance with moderate optical contrast (32%) and fast response time (0.9 s). [ABSTRACT FROM AUTHOR]

Despite the higher efficiency, larger color range and faster stimulus response of polymeric electrochromic materials, their poor cyclability strongly hampers their application in optoelectronics. As an original strategy to stabilize and further nanostructure these polymers, herein an efficient encapsulation and in situ polymerization inside highly porous metal–organic frameworks (MOFs) is reported. In particular, the successful accommodation of poly(3,4-ethylendioxythiophene) (PEDOT) and its partially oxidized polarons inside the mesopores of the nontoxic iron trimesate MIL-100(Fe) is convincingly proved by a large panel of experimental techniques. Remarkably, the polymer–MOF interaction occurring for entrapped PEDOT within the pores (deeply assessed by experimental and simulation methods) might be responsible for the enhanced electrical conductivity of the resulting PEDOT@MIL-100(Fe) composite when compared to the insulating MIL-100(Fe) and the conductive free PEDOT. Furthermore, it was possible to observe the electrochromic properties of the PEDOT@MIL-100(Fe) composite, achieving an improved stability and good cyclability as a consequence of the effective protection by the MOF matrix. [ABSTRACT FROM AUTHOR]

Abstract Four novel multifunctional electrochromic materials (PTT, PDTT, PNT and PDNT) based on tetraphenylethylene (TPE) and triphenylamine (TPA) units by Stille coupling reaction were prepared. Electrochemical impedance spectroscopy (EIS) measurements found that four polymers had low resistance values which improved their electrochemical and electrochromic properties. In addition, the maximum coloration efficiency (CE; η) value is 126 cm2/C at 1246 nm of PDTT, bleaching and coloring response times are 2.6 s and 1.6 s, respectively. There is no significant change of performance after a 100 cycle scanning. In addition to their excellent electrochromic properties, they also exhibit a strong aggregation-induced emission (AIE) effect. Furthermore, the fluorescence color of PDNT changed from bright green to black when voltage was applied from 0.0 to 1.6 V. Four polymers responded rapidly to light and they maintained stability over a 1000 s cycle. Highlights • Novel multifunctional electrochromic materials have been synthesized and studied. • Polymers exhibit a strong aggregation-induced emission (AIE) effect. • Polymers exhibit excellent electrochromic and high electrofluorochromic properties. [ABSTRACT FROM AUTHOR]

By employing planar thieno[3,2‐b]thiophene (TT) as end‐capped units and famous 3,4‐ethylenedioxythiophene (EDOT) or its all‐sulfur analog 3,4‐ethylenedithiathiophene (EDTT) as cores, two conjugated oligomer, TT‐EDOT‐TT and TT‐EDTT‐TT, have been synthesized and electropolymerized into electrochromic polymer films, P(TT‐EDOT‐TT) and P(TT‐EDTT‐TT), respectively. Due to strongly noncovalent inter/intramolecular interactions from SS attraction of TT‐EDTT‐TT, it has twisted molecular configuration in contrast to planar TT‐EDOT‐TT. Spectroscopic, electrochemical, morphological as well as theoretical calculation studies of these oligomers or polymers were carried out to reveal the significant influence of such molecular geometry on their physicochemical and optoelectronic properties. According to electrochromic kinetics, P(TT‐EDTT‐TT) presented preferable electrochromic behavior such as the higher optical contrast (70.8%), favorable coloration efficiency (331.3 cm2 C−1) and fast response time (0.72 s). This research will help us deeply understand the effect of spatial organization of precursor molecules on the properties of electrochromic polymers and provides a promising strategy to develop high‐performance electrochromic materials. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1041–1048 [ABSTRACT FROM AUTHOR]

Abstract The cracking of electrochromic materials due to aging or reiterative bending is a major problem which noticeably degrades the performances of electrochromic devices. In this research, a novel self-healing electrochromic polymer PPFMA was synthesized, which integrated the electrochromic triphenylamine unit and self-healing Diels-Alder group. The PPFMA film shows all superior electrochromic properties, such as stable color changes (yellow to green to blue) with a maximum optical contrast of 42.7% at 1050 nm and high coloration efficiency of 108.3 cm2C-1. Meanwhile, the polymer PPFMA film also shows excellent self-healing performance, cracks on the film surfaces (bleached or colored states) could be self-healed at 110 °C within 4 min, and the self-healing rate is about 80%. The results indicate that polymer PPFMA has the mutual independent bifunction of electrochromic and self-healing, it is a promising material to solve the problem of cracks generation for the electrochromic device. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Materials that change color in response to external stimuli can cater to diverse applications from sensing to art. If made flexible, stretchable and weavable, they may even be directly integrated with advanced technologies such as smart textiles. A new class of engineered composite based on polydiacetylene (PDA) functionalized carbon nanotubes (CNT) shows tremendous potential in this regard. While the inherent multi stimuli chromatic response of the polymer (blue to red) is retained, the underlying conducting CNTs invoke electrochromism in PDA. Further, the fiber form factor of dry-spun CNT yarns facilitate direct weaving of large scale electrochromic fabrics, where current flow and thus color change can be accurately controlled. This review summarizes the fundamental aspects of CNT yarns and PDAs, focusing especially on their interaction chemistry which results in the scientifically and commercially appealing electrochromic transition in these hybrids. [ABSTRACT FROM AUTHOR]

The synthesis and electrochromic properties of a novel regiosymmetric polymer based on 3,4-ethylenedioxythiophene, poly(2,3-bis(bromomethyl)-2,3-dihydrothieno[3,4-b][1,4]dioxine) (PEDOT(MeBr) 2 ) were highlighted. The monomer was electrochemically polymerized via repetitive cycling between 0 and 1.8 V in lithium perchlorate (LiClO 4 )–acetonitrile (ACN) electrolytic medium. The corresponding polymer was characterized by FTIR spectra, scanning electron microscopy, cyclic voltammetry, UV–Vis-NIR spectroscopy and colorimetry. It features a reversible redox process and demonstrates a stable blue-to-transmissive electrochromic behavior with very low driving potentials (−0.1 and 0.65 V). Additionally the polymer film exhibits enhanced optical contrast (60% at 669 nm) and improved coloration efficiency (183.1 cm 2 /C at 100% full contrast during bleaching process) which are higher than those of PEDOT, a relatively longer response time compared with PEDOT and reasonable redox stability. [ABSTRACT FROM AUTHOR]

Electrochromic polymers have attracted much attention due to their potential applications in displays, smart windows, intelligent mirrors, and wearable devices. Here, a novel polyamic acid containing aniline pentamer with improved electrochromic properties and new functionalities was synthesized via oxidative coupling polymerization, followed by post-polymerization of tetraaniline, polyhedral oligomeric silsesquioxane, and fluorene, respectively. With the introduction of tetraaniline pendants, the resultant polymer exhibits improved electrochromic performance with high optical contrast value and rapid switching rate, because of the high content of electrochromic units in the polymeric structure. The polyamic acid functionalized with polyhedral oligomeric silsesquioxane, demonstrates a great enhancement of switching rate in the electrochromism, due to the rapid electrolyte migration through polymer film under electrochemical potentials. In addition, a new electrofluorochromic feature is easily achieved through the introduction of fluorescent fluorene groups into the polymeric architecture. [ABSTRACT FROM AUTHOR]

ABSTRACT Electrochromic polymers based on [1,2,5]thiadiazolo[3,4-g]quinoxaline acceptor and thiophene, 3,4-ethylenedioxythiophene and 3,3-didecyl-3,4-proylenedioxythiophene donors, namely poly(6,7-diphenyl-4,9-di(thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline) ( P1), poly(4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(2,3-dihydrothieno[3,4-b][1,4]dioxin-7-yl)-6,7-diphenyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline) ( P2), and poly(4-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-9-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-8-yl)-6,7-diphenyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline) ( P3), respectively, were electrochemically and/or chemically synthesized and characterized. Electrochemical and optical properties of the polymers were then investigated. The results, which were obtained electrochemically and optically, indicate that the polymers bearing the same acceptor and different donor units have a band gap range of 0.59-1.24 eV depending on the strength and size of the donor units and band gap determination method. A significant finding in this study was the phenomenon that when the acceptor is physically huge, the general rule that a weak donor would have a high band gap whereas a strong donor would have low band gap can be broken due to the torsional angles/steric hindrances involved with physically large donor molecules. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3483-3493 [ABSTRACT FROM AUTHOR]

A series of phenantrene centered donor-acceptor type electroactive 3,4-ethlenedioxythiophene (EDOT) monomers (EP-X) containing N, S and Se heteroatom on the bezophenantra-X-diazole acceptor unit have been synthesized by Stille coupling reaction. These monomers were electrochemically polymerized by potentiodynamic method to obtain electrochromic polymer films. Spectro-electrochemical properties were also investigated by UV-vis absorption connected with the cyclic voltammetry measurements. The polymer films exhibited a remarkable trend of visible color (yellow, orange, red) at the neutral state due to changing the central acceptor moiety. These polymer films have multielectrochromic properties by means of moderately changing the absorbance/transmittance at the visible regime upon applied positive potentials. The donor-acceptor interaction at the neutral state correlated by DFT calculations was also supported by the interesting trend in the colors of these polymers. Finally, the electrochromic performance of EP-X polymer films represented a high redox stability, reasonable contrast ratio, coloration efficiency and response times. [ABSTRACT FROM AUTHOR]

Two N -phenylcarbazole and triphenylamine end-capped, 2,7-bis(diphenylamino)naphthalene-cored dicarboxamides were prepared by the condensation reactions from N,N ′-bis(4-aminophenyl)- N,N ′-bis(4-methoxyphenyl)-2,7-naphthalenediamine with two equivalent amount of N -(4-carboxyphenyl)carbazole and 4-carboxytriphenylamine, respectively. These two dicarboxamides can be electropolymerized into electroactive films on the electrode surface in an electrolyte solution via the oxidative coupling reactions between the terminal arylamino groups. The electro-generated polymer films exhibited reversible electrochemical oxidation processes and strong color changes upon electro-oxidation, which can be switched by potential modulation. The electrochromic films did not delaminate from the electrode surface upon cycling electrochemically between their neutral and oxidized states. [ABSTRACT FROM AUTHOR]

Three dithienylpyrroles (1-(4-(methylthio)phenyl)-2,5-di(thiophen-2-yl)-pyrrole (MPS), 1-(4-methoxyphenyl)-2,5-di(thiophen-2-yl)-pyrrole (MPO), and 4-(2,5-di(thiophen-2-yl)-pyrrol-1-yl) benzonitrile (ANIL)) were synthesized and their corresponding polydithienylpyrroles (PSNS) were electrosynthesized using electrochemical polymerization. Spectroelectrochemical studies indicated that poly(1-(4-(methylthio)phenyl)-2,5-di(thiophen-2-yl)-pyrrole) (PMPS) film was green, dark green, and brown in the neutral, oxidation, and highly oxidized state, respectively. The incorporation of a MPS unit into the PSNS backbone gave rise to a darker color than those of the MPO and ANIL units in the highly oxidized state. The PMPS film showed higher ΔTmax (54.47% at 940 nm) than those of the PMPO (43.87% at 890 nm) and PANIL (44.63% at 950 nm) films in an ionic liquid solution. Electrochromic devices (ECDs) employing PMPS, PMPO, and PANIL as anodic layers and poly(3,4-(2,2-diethypropylenedioxy)thiophene)(PProDOT-Et2) as a cathodic layer were constructed. PMPO/PProDOT-Et2 ECD showed the highest ΔTmax (41.13%) and coloration efficiency (674.67 cm2·C-1) at 626 nm, whereas PMPS/PProDOT-Et2 ECD displayed satisfactory ΔTmax (32.51%) and coloration efficiency (637.25 cm2·C-1) at 590 nm. Repeated cyclic voltammograms of PMPS/PProDOT-Et2, PMPO/PProDOT-Et2, and PANIL/PProDOT-Et2 ECDs indicated that ECDs had satisfactory redox stability. [ABSTRACT FROM AUTHOR]

Poly(3-alkylthiophene)s (P3ATs) are a promising class of electrochromic materials because of their convenient processability and environmental stability. The adhesion of electroactive polymer coatings on a transparent conducting substrate is a significant factor affecting the durable colour-changing life of electrochromic devices such as visual displays and switchable windows. Traditional electrochromic coatings on transparent ITO glass electrodes often have poor cycling lifetimes, due to incompatibility between the polymers and the inorganic substrates. However, providing a covalently-bonded network between the active electrochromics and the ITO glass is an efficient method to increase the adhesion and hence to extend the service time; the research described here used Suzuki-Miyaura coupling of N-(3-trimethoxysilylpropyl)pyrrole (TMP) onto poly(3-hexylthiophene) (P3HT), as a precursor to a sol-gel reaction. The Si-O-metal network produced between the siloxane groups and metal oxide after the sol-gel reaction served to enhance the adhesion of the poly(3-hexylthiophene) onto ITO glass. With this stronger bonding, the colour-switching service time was found to be extended considerably by the observation of repeated electrochemical cycling tests. In addition, the electro-optic and electrochemical properties of copolymers with various molar substitution ratios of TMP on P3HT were investigated by cyclic voltammetry and UV-visible spectroscopy. The π-π* transition energy of P3HT increased with the degree of bromo-substitution, but diminished again after substituting with TMP. The hysteresis in electrochromic switching also became more noticeable with increased bromo-substitution on the P3HT, but it decreased when TMP was attached to the thiophene rings. [ABSTRACT FROM AUTHOR]

In recent years, high-performance polymers (HPPs) have received much attention for their excellent electrochromic (EC) properties and applications in optoelectronic research. Herein, a series of novel poly(arylamine sulfone) (PAAS) and poly(arylamine ketone) (PAAK) type HPP electrochromic films have been prepared directly on the Indium tin oxide (ITO) substrates by electrochemical polymerization. Notably, the triphenylamine-based polymers (P-TST and P-TKT) have higher optical contrast (capable of exceeding 40%), shorter switching times (coloring time t c and bleaching time t b can be as low as 1 s), and better cycling stability (optical contrast remains around 80% after a cycling test of 500 s) than the carbazole-based polymers (P-CSC and P-CKC). Performance aside, this work provides a simple, rapid, and efficient method to synthesize polyarylsulfone/ketone-based electrochromic materials for the first time. With this method, the cost is significantly reduced, production efficiency is accelerated, and the problem of difficult film formation due to poor solubility after conventional polymerization is solved, providing a feasible solution for subsequent large-scale production and practical applications. PAASs/PAAKs electrochromic films are synthesized directly by electrochemical polymerization. It is not only simple and fast, but also can solve the problem that conventional polymerization products are unfavorable for processing due to poor solubility. The P-TKT devices have not failed after 24,000 s of continuous operation and have the potential for large-scale applications. [Display omitted] • Direct synthesis of PAASs/PAAKs films by electrochemical polymerization. • The method is facile and solves processing problems of conventional polymerization. • P-TKT ECD maintains an optical contrast of over 70% after a cycling test of 24,000 s. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three solution-processable donor-π-donor–acceptor-donor type polymers were synthesized. • The films exhibited neutral green or dark yellowish with multi-color electrochromism. • The optoelectronic properties could be modulated by changing donor-to-acceptor ratios. • The polymers present satisfied switching speed, coloration efficiency, optical contrast. Novel high-performance D-π-D-A-D type polymeric electrochromic materials consisting of phenylene π-bridged core alternated with the donor cyclopentadithiophene derivatives and the D-A-D moiety thiophene-diketopyrrolo[3,4- c ]pyrrole-thiophene (TDPPT), differing by the ratio of donor to acceptor units incorporated, were achieved by Suzuki cross-coupling reaction. The polymer films displayed intense dual visible absorptions in their neutral states, which were modulated both in the positions and relative intensities by regulating the chemical composition as well as the donor-to-acceptor ratio in the polymer backbone, allowing the facile manipulation of the neutral-state colors. The polymer PBDC-1 exhibited a deep green neutral-state color. PBDC-2 and PBDC-3 also demonstrated two strong and broad absorptions, but a relative small gap of transmission in the orange-yellow region, giving the films dark yellowish-black color. In situ optical monitoring revealed that all the polymers underwent surprising multi-color variations upon the redox cycling, simultaneous with fast switching speeds, high coloration efficiencies, and large optical contrasts. [ABSTRACT FROM AUTHOR]

In this study, the electropolymerization of ethyl and methyl substituted asymmetrical nitrogen analogs of 3,4-ethylenedioxythiophene (OEt and OMe) were synthesized, characterized and their electrochemical properties were investigated. Both polymers (POEt and POMe) were synthesized electrochemically and characterized using spectroelectrochemical technique to determine optical changes of the resulting polymer films. Electrochemical studies demonstrated that these polymers exhibited a significantly low oxidation potential compared to their analogs reported in the literature. These polymers also provided a low optical bandgap with good optical contrasts. Furthermore, multi-electrochromic properties upon different applied potentials revealed that these polymers have potential applications in electrochromic devices. As a further characterization, their dual type electrochromic devices were constructed with poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA) which is transmissive in its both redox states. Devices were characterized via electrochemical and spectroelectrochemical techniques. [ABSTRACT FROM AUTHOR]

ABSTRACT 3-Dodecylthiophene end-capped two monomers: 2,8- bis-(4-dodecyl-thiophen-2-yl)-dibenzothiophene (DBT-3DTh) and 2,8- bis-(4-dodecyl-thiophen-2-yl)-dibenzofuran (DBF-3DTh) were synthesized via Stille coupling reaction. Both monomers exhibited emission peaks at about 400 nm with fluorescence quantum yields ranging from 0.16 to 0.21. The corresponding electroactive polymers poly(2,8- bis-(4-dodecyl-thiophen-2-yl)-dibenzothiophene) (PDBT-3DTh) and poly(2,8- bis-(4-dodecyl-thiophen-2-yl)-dibenzofuran) (PDBF-3DTh) were obtained by electropolymerization method and displayed good electrochemical stability. Both polymers switched between light gray in the neutral state and blue in the oxidized state. Kinetic investigations showed that PDBT-3DTh exhibited a maximum optical contrast (Δ T %) of 25.23% at 575 nm with the coloration efficiency (CE) of 196 cm2 C−1. However, the electrochromic properties of PDBF-3DTh were inferior to PDBT-3DTh. Further detailed discussions with EDOT and 3-alkylthiophenes end-capped DBT/DBF hybrid electrochromic polymers were comparatively studied. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1468-1478 [ABSTRACT FROM AUTHOR]

We demonstrate the electrically controlled and reversible plasmonic signature of hybrid polymer-metal nanostructures composed of core/shell nanostructures: gold nanocubes (AuNCs) coated with electrochromic polyaniline (PANI) shells. A reversible tuning of the localized surface plasmon resonance (LSPR) peak of the AuNC core was obtained by applying an electrical potential that caused a reversible oxidation state change in the electroactive PANI nanoshell. A significant shift of the main LSPR peak was achieved with high reversibility and electrochemical stability due to the interplay of the local decay of the electromagnetic field and the controlled thickness of the surrounding polymer shell. Here, the PANI shell acts as an electroactive medium as well as a physical spacer to prevent uncontrollable plasmonic coupling. The most efficient LSPR shift can be induced by the refractive index change of nanoscale PANI shell thickness lower than the electromagnetic field decay length of the given gold nanoparticles. Single particle studies showed that coupling of plasmon resonances of densely packed nanocubes with thicker PANI shells was prevented and the extinction signature of individual core/shell nanocubes remained mostly unchanged after their assembly into densely packed aggregates. Therefore, these core/shell structures could preserve the original plasmonic signature of individual nanostructure by damping plasmonic coupling between AuNC cores. [ABSTRACT FROM AUTHOR]

Electroactive poly(2,5-Bis(9-methyl-9 H-carbazol-3-yl)-1,3,4-oxadiazole) (PolyBCO) film was synthesized to form a highly stable conducting polymer with excellent electrochromic properties. The polymer was characterized by cyclic voltammetry, UV–Vis-NIR spectroscopy and colorimetry. Spectroelectrochemistry analysis demonstrated that the polymer can undergo both p-type and n-type doping processes. The polymer has four accessible color states. Further kinetic studies demonstrated that the polymer revealed high contrast ratio (75%), fast response time (0.9 s), excellent stability and color persistence. A dual-polymer electrochromic device was constructed in sandwich configuration where PolyBCO was used as the anodically coloring material. The device switches between a transmissive light gray state and a blue-colored state with a fast response time and high stability. [ABSTRACT FROM AUTHOR]

A series of dithienothiophene-based electrochromic polymers are synthesized by a Stille coupling reaction of 2,6-bis(trimethylstannyl)dithieno[3,2- b:2′,3′- d]thiophene, 2,5-dibromo-3,4-bis(dodecyloxy)thiophene, and tris(4-bromophenylamine). The resulting polymers have high molecular weights in the range of 59 200 to 81 300 g mol−1, and good solubility in common organic solvents. The polymer films are purple/red in neutral states and gradually become gray when oxidized to an intermediate state and blue when fully oxidized. Incorporation of triphenylamine into the polymer chains has resulted in a significant increase in the redox stability, which renders this a potential method to create high-performance electrochromic polymers. [ABSTRACT FROM AUTHOR]

Because of their optical and electronic properties, polythiophenes and their derivatives, especially poly(3,4-alkylenedioxythiophene) s, are among the most promising materials in the field of electrochromic polymers. The properties of these polymers can be tuned by replacing the sulfur atom of the thiophene moiety with a selenium atom, because selenium has a lower electronegativity, a higher metallic character, a larger atomic size, and greater polarizability than sulfur. This approach has opened the door to a new and vibrant class of conjugated polymers. Today 3,4-alkylenedioxyselenophenes are thought as powerful competitors to 3,4-alkylenedioxythiophenes. Here, an overview is presented of poly(3,4-alkylenedioxyselenophene)s, as one of the most attractive groups of conjugated polymers. The design, synthesis, and applications of poly(3,4-alkylenedioxyselenophene)s and their derivatives are discussed in detail and compared with the corresponding features of their thiophene analogues. The electrochemical and electrochromic properties and band gaps of poly(3,4-alkylenedioxyselenophene) s are also discussed in relation to their chemical structures. 1 Introduction 2 Polyselenophenes 3 Poly(3,4-ethylenedioxyselenophene)s 4 Poly(3,4-propylenedioxyselenophene)s 5 Conclusions [ABSTRACT FROM AUTHOR]

Metallo-supramolecular polyelectrolytes (MEPE) based on iron(II)-acetate and 1,4-bis(2,2':6',2"-terpyridin-4'-yl)benzene are assembled by layer-by-layer deposition on transparent electrode surfaces. When a potential is applied, the color of the film can be switched from blue to transparent. Due to the strong absorption and the fast switching speed, the color change is readily observed with the eye. The device shows reversible switching and long-term stability. The experiment demonstrates the basic concept of electrochromic windows, an upcoming technology. [ABSTRACT FROM AUTHOR]

In this work, four new terpyridine-Fe (Ⅱ) coordination polymers (FeQ1 ∼ FeQ4) consisting of quinoxaline-based π-spacers were developed, and further deposited on ITO substrates via spin-coating process for electrochromic applications. All these Fe (Ⅱ) coordination polymers exhibited fast and reversible electrochromic switching between purple and yellow with high optical contrast as well as high coloration efficiency, and showed good cycle stability. The variation of substituents on the quinoxaline-based π-spacers resulted in tunable electrochromic properties. Remarkably, polymers FeQ3 and FeQ4 with aliphatic substituents on the ligands showed superior optical contrast up to 76.7% and 81.6% around 575 nm, with coloring time around 0.5 s and bleaching time around 2 s, respectively. To the best of our knowledge, FeQ4 gained the highest optical contrast value among the reported electrochromic materials based on Fe-complexes up to date. We developed four terpyridine-Fe(II) coordination polymers consisting of quinoxaline-based π-spacers for electrochromism with enhanced performance. [Display omitted] • Four new Fe(II) coordination polymers were prepared for electrochromics. • Quinoxaline-based π-spacers were introduced for enhanced electrochromic performance. • FeQ4 showed fast purple-to-yellow switching with high optical contrast over 80%. [ABSTRACT FROM AUTHOR]

ABSTRACT Reported are syntheses of several new monomer precursors of cathodically coloring conducting polymers (CPs), based on a propylene dioxythiophene skeleton. These are shown to yield CPs-both as homopolymers and as copolymers-that are nearly 'perfectly' matched electrochemically and electrochromically with a set of anodically coloring poly(aromatic amines), for use in dual-polymer electrochromic lenses. Resulting dual-polymer electrochromic lenses display very high light/dark contrast (typically up to 70/7% or 50/0.5% Transmission (integrated over visible spectrum, vs. air reference), Haze < 2%, very high cyclability (> 10 K cycles), multiyear shelf life, appealing transparent to dark-blue-black transition, and excellent optical memory. Dramatic lowering of switching time, from 8 to < 1 s, is demonstrated using unique applied-potential algorithm resident on inexpensive Microcontroller chip. Working, practical dual-polymer electrochromic spectacles are demonstrated with electrochromic lenses retrofitted to spectacles meeting ANSI Z87.1, GL-PD 10-12 (U.S. military) specifications. These incorporate photosensor, rechargeable Li battery, Microcontroller, allow for automated operation. Ab-initio-design spectacles, also conforming to above specifications, are also demonstrated, with components seamlessly hidden within frame. To the best of our knowledge, the electrochromic lenses and sunglasses reported herein represent the best visible-region electrochromic performance for dual-polymer CP electrochromic systems to date and the first practical implementation in working sunglasses. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41043. [ABSTRACT FROM AUTHOR]

We have synthesized two new D-A electrochromic polymers; poly( N,N’ -bis(2-hexyl)-2,6-dithiophene-1,4,5,8-naphthalenediimide) (PTNDI) and poly( N,N’ -bis(2-hexyl)-2,6-(3,4-ethylenedioxythiophene)-1,4,5,8-naphthalenedimiide) (PENDI) bearing a naphthalenedimiide chromophore in the backbone. Structural characterization of initial compounds and products were carried out by using FT-IR and 1 H-NMR spectroscopies. The optical and electrochemical properties of these polymers were investigated by UV-Vis absorption spectroscopy and cyclic voltammetry, respectively. The results of spectroelectrochemical studies indicate that both polymers reveal various colors due to ambipolar redox behavior at cathodic and anodic regime. Both polymer films have reasonable redox stability (in the range of 75-80% after 1000 cycles), coloration efficiency (in the range of 80-100 cm 2 C −1 ), and response time (approx. 1s). Moreover, it is clearly seen that replacing donor unit from thiophene to EDOT results in change only in neutral state color. [ABSTRACT FROM AUTHOR]

Propylenedioxythiophene (ProDOT) polymers are synthesized using an oxidative polymerization route that results in methacrylate substituted poly(ProDOTs) having a Mn of 10-20 kDa wherein the methacrylate functionality constitutes from 6 to 60% of the total monomer units. Solutions of these polymers show excellent film forming abilities, with thin films prepared using both spray-casting and spin-coating. These polymers are demonstrated to crosslink upon UV irradiation at 350 nm, in the presence of an appropriate photoinitiator, to render the films insoluble to common organic solvents. Electrochemical, spectroelectrochemical, and colorimetric analyses of the crosslinked polymer films are performed to establish that they retain the same electrochromic qualities as the parent polymers with no detriment to the observed properties. To demonstrate applicability for multi-film processing and patterning, photolithographic patterning is shown, as is desired for fully solution processed and patterned devices. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two polymers based on phenanthra-9,10-quinone were synthesized and characterized. [•] Both of the two polymers exhibit multichromic properties. [•] The structure of substitution influences electrochromic properties of the polymers. [•] One polymer had high optical contrast, the other exhibited excellent response time. [ABSTRACT FROM AUTHOR]

Fe-based metallo-supramolecular polymer (polyFe), composed of Fe(II) ions and bis(terpyridyl)benzene, is known as a good electrochromic (EC) material. For the first time, to improve the EC properties, we prepared nanocomposites comprising polyFe and a layered inorganic–imidazoline covalently bonded hybrid (LIIm) by simply mixing them in methanol and then examined the effect of the nanocomposition on EC properties. The obtained blue/purple-colored composites (polyFe/LIIm composites) were demonstrated by scanning electron microscopy (SEM) to comprise a structure of LIIm nanoparticles coated with amorphous polyFe. Interestingly, X-ray diffraction (XRD) measurements suggested that there was no intercalation of polyFe in the interlayer space of LIIm. Ultraviolet-visible (UV-vis) spectroscopy measurements demonstrated that light absorption close to 600 nm was attributed to metal-to-ligand charge transfer (MLCT) from the Fe(II) ion to the bisterpyridine ligand and was influenced by LIIm in the composites. The composites exhibited a pair of redox waves, assigned to the redox between Fe(II) and Fe(III), in the cyclic voltammograms; moreover, the composites were estimated to be diffusion controlled. Thin composite films demonstrated reversible EC changes, triggered by the redox reaction of the metal. Furthermore, the results show that the nano-scale composition of the metallo-supramolecular polymers with LIIm can effectively improve the memory properties without reducing the contrast in transmittance (ΔT) of 70–76% in EC changes after applying 1.2 V vs. Ag/Ag+. The EC properties varied with varying ratios (3/0.1, 0.5, 1, and 5) of the polyFe/LIIm, and the ratio of 3/1 exhibited the longest memory and largest MLCT absorption peak among composites. The results show that the polyFe/LIIm composites are useful EC materials for dimming glass applications, such as smart windows. [ABSTRACT FROM AUTHOR]

A hybrid thienylene-phenylene conjugated molecule with pendent double bond unit on side chain, 5,5'-(2,5-bis(hex-5-en-1-yloxy)-1,4-phenylene)bis (2,3-dihydrothieno[3,4- b ] [1,4] dioxine) (EDOT- ene -BE), was designed, and its corresponding polymer poly(EDOT- ene -BE) with similar-network structure was prepared by electrochemical method. The introduction of pendent double bond unit has little influence on the optical absorption and oxidation potential of EDOT- ene -BE. The pendent double bond unit could be attached on polymeric chain of poly(EDOT- ene -BE), leading to linear polymeric chain turning into similar-network structure. The microstructure makes poly(EDOT- ene -BE) film exhibit faster respond speed and higher coloration efficiency than poly(EDOT-BE) without pendent double bond unit. The kinetics indicate that poly(EDOT- ene -BE) could switch between oxidation and reduction states in 0.4 s, which is among one of the fastest respond times. After annealing, the polymerization between pendent double bond units leads to the formation of poly(EDOT-BE- net) with network molecular structure. As poly(EDOT- ene -BE), poly(EDOT-BE- net) possesses faster respond speed relative to poly(EDOT-BE), however, the respond speed is slower than that of poly(EDOT- ene -BE). These results demonstrate that the introduction of pendent double bond unit in side chain results into the formation of similar-network molecular structure, which is proved to be an effective strategy to improve the properties of polymer electrochromic materials. [Display omitted] • An electrochromic polymer with pendent double bond units on side chains was prepared. • The pendent double bonds make polymer possess similar-network structure. • The polymer exhibits faster respond speed and higher coloration efficiency than the control. [ABSTRACT FROM AUTHOR]

We report here the rational design of novel black-to-highly transmissive electrochromic material consisting of two different complementary units and a π-conjugated pendant group. Polymerization of the triazine-cored super-structured molecule has yielded a high optical contrast black electrochromic conductive polymer by a combination of the complementary spectra of polycarbazole, polyaniline, and pyrene-based π-conjugated pendant group. The polymer has exhibited a high optical contrast of up to 81% covering the range of 400–800 nm in the spectrum. The PTPCFd film is highly transparent at neutral state, then gray, and finally turns to deep black color covering a broad absorption in the visible range at oxidized state. This work could provide a new method for the design and synthesis of practical black-to-transmissive materials. [ABSTRACT FROM AUTHOR]

With the developing demand for the smart stimuli-responsive materials, the functional conjugated polymers are appealing for the electrochromic materials, due to their adjustable structure, rapid switching time and facile processability. Series of innovative conjugated electrochromic polymers consisting of triphenylamine or phenothiazine group have been designed and synthesized. Other than the conventional electrochromic polymers, our designed polymers can control colors of both reduction and oxidation states with applied external potential. With incorporation of side anode electrochromic group, the polymers bearing triphenylamine group can achieve grey-blue color at oxidation states and those containing phenothiazine group can present dark purple color at their oxidation states. With further modification of polymer backbone, the reduction colors of electrochromic polymers can be regulated as well. Therefore, the effective combination of anode and cathode electrochromic materials in one can realize color regulation for the dual-states as expected. Additionally, the polymers bearing triphenylamine group can further achieve light induced coloration effect as the triphenylamine group can act as light-induced energy source to drive the reduction of polymer backbone. Therefore, the design and effects of these polymers can broaden application range of electrochromic polymers and provide new strategies for energy saving material design. [Display omitted] • Polymers integrating cathodic and anodic electrochromic molecule are synthesized. • The polymers are able to control the color of both reduction and oxidization state. • The polymers can achieve light-induced coloration under light irradiation. [ABSTRACT FROM AUTHOR]