Electrosynthesis and characterization of an electrochromic material from poly(1,4-bis(2-thienyl)-benzene) and its application in electrochromic devices

1,4-Bis(2-thienyl)-benzene monomer is successfully synthesized via coupling reaction. Poly(1,4-bis(2-thienyl)-benzene) (PBTB) is electrochemically synthesized and characterized. Resulting polymer film has distinct electrochromic properties. Its application in electrochromic devices (ECDs) is discussed. PBTB is switched between yellow in the neutral state and green in the oxidized state. Electrochromic switching of PBTB film is performed and the polymer film shows a maximum optical contrast (ΔT %) of 44.8% at 610 nm in visible region with a response time of 1.6 s. The coloration efficiency (CE) of PBTB is calculated to be 162 cm² C⁻¹. Electrochromic device (ECD) based on PBTB and poly(3,4-ethylenedioxythiophene) (PEDOT) is also constructed and characterized. Maximum contrast (ΔT %) and switching time of the device are measured as 29.5% and 0.43 s at 628 nm. The CE of the device is calculated to be 408.9 cm² C⁻¹. Clear change from green (at neutral state) to blue color (at full oxidized state) of this ECD is demonstrated with reasonable cycle life.     

Electrochemical and chemical investigations of the co-polymers of 3-aminobenzenesulfonic acid with aromatic amines for their application in electrochromic devices

The chemical oxidative polymerization and electrochemical polymerization of 3-aminobenzenesulfonic acid with aromatic amines have been carried out in p-toluenesulfonic acid which acts as a supporting electrolyte as well as an external dopant. The presence of –SO₃H groups in the ABSA co-monomer allows the copolymer to acquire intrinsic protonic doping ability. The electrochemically synthesized polymers and copolymers have been characterized by cyclic voltammetry for analyzing the growth of copolymers and chronoamperometry studies for their applications to the electrochromic devices. In addition to construction of electrochromic devices (ECDs), the electrochromic properties of the polymer films were further investigated. Electrochromic switching stability of the devices was estimated from switching times between their oxidized and reduced states, which indicates that the homopolymers and copolymer can be used for promising electrochromic devices. Chemically synthesized copolymers were also characterized using various techniques like Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy and electrical conductivity at room temperature.     

Matched‐dual‐polymer electrochromic lenses,using new cathodically coloring conducting polymers,with exceptional performance and incorporated into automated sunglasses

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.     

Faradaic charge corrected colouration efficiency measurements for electrochromic devices

We report a new technique for measuring colouration efficiency (CE) for electrochromic polymers and devices. Faradaic charge associated with redox activity leading to chromic change was extracted from the total charge flow during a device switch. Typically, Faradaic charge is extracted from the total charge by first measuring a blank device (i.e. no polymer deposited). This is used as the baseline and subtracted from subsequent measurements with the polymer deposited into the device. The method is open to inaccuracies if the surface area before and after polymer deposition is different or if the inherent capacitance of the device is altered by the addition of the polymer(s). The new technique does not suffer from this drawback as it dispenses with the need to measure blank devices. To investigate the utility of this method a poly(3,4-ethylenedioxthiophene) (PEDOT) and polyaniline (PANI) electrochromic cell was tested. CE measurements at an optical density change of 95% (λ = 555 nm) were recorded for the following three conditions: uncorrected, CE_UC = 388 cm²/C; background corrected, CE_BC = 391 cm²/C and; Faradaic corrected, CE_FC = 2173 cm²/C. The result highlights the fact that the CE value of chromic polymers or devices may be higher than what is currently being reported.     

Synthesis and characterization of thiophene functionalized polystyrene copolymers and their electrochemical properties

Thiophene functionalized polystyrene samples (TFPS) were synthesized by atom transfer radical polymerization (ATRP) of styrene, followed by Suzuki coupling with 3‐thiophene (Th) boronic acid. Conducting graft polymer of TFPS with thiophene was achieved at 1.5 V in tetrabutylammonium tetrafluoroborate/dichloromethane (TBAFB/DM) by electrochemical methods. Spectroelectrochemical analysis of the resulting copolymers [P(TFPS‐co‐Th)] reflected electronic transitions at 449, 721 and 880 nm, revealing π ? π* transition, polaron and bipolaron band formation, respectively. We also successfully established the utilization of dual type complementary colored polymer electrochromic devices using P(TFPS‐co‐Th)/poly(3,4‐ethylenedioxythiophene (PEDOT) in sandwich configuration. The switching ability, stability and optical memory of the electrochromic device were investigated by UV–visible spectrophotometry and cyclic voltammetry. Device switches between brown and blue color with a switching time of 1.3 s were prepared with optical contrast (%ΔT) of 25 %. Copyright © 2005 Society of Chemical Industry     

New polymer syntheses. IX. Synthesis and properties of new conducting polyazomethine polymers containing main chain cycloalkanone and pyridine moieties

Novel polyazomethines containing cycloalkanones or pyridine moieties were synthesized by the polycondensation of 2,5‐bis(m‐aminobenzylidene)cyclopentanone (BMAP, IV), 2,6‐bis(m‐aminobenzylidene)cyclohexanone (BMAH, V), 2,6‐bis(p‐aminobenzylidene)cyclohexanone (BPAH, VI), and 2,6‐bis(m‐aminostyryl)pyridine (BMAS, VIII) diamines with terephthalaldehyde in EtOH at 25°C. These polymers were yellow to orange in color, had reduced viscosities up to 1.42 dL/g, and had electric conductivities as high as 10⁻¹¹–10⁻¹² S cm⁻¹. All the polyazomethines were insoluble in common organic solvents but dissolved completely in concentrated sulfuric acid. However, they were readily hydrolyzed in concentrated H₂SO₄. X‐ray diffraction diagrams showed that the crystallinities of the polyazomethines were low. These azomethine polymers showed high thermal and thermooxidative stability and exhibited no appreciable decomposition up to 400°C in air. The electronic spectra of the polymers indicated a large bathochromic shift of the π–π* absorption band (∼360 nm) that was due to the presence of CN bonds in the polymer main chain. Doping with iodine dramatically raised the conductivity and produced dark brown to black colored semiconductive polymers with a maximum conductivity on the order of 10⁻⁷ S cm⁻¹. Furthermore, the morphology of selected examples of the four polyazomethines was examined by scanning electron microscopy. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1218–1229, 2000     

Synthesis and characterization of poly(thiophen‐3‐yl acetic acid 4‐pyrrol‐1‐yl phenyl ester‐co‐N‐methylpyrrole) and its application in an electrochromic device

Copolymer of thiophen‐3‐yl acetic acid 4‐pyrrol‐1‐yl phenyl ester (TAPE) with N‐methylpyrrole (NMPy) was synthesized by potentiostatic electrochemical polymerization in acetonitrile–tetrabutylammonium tetrafluoroborate solvent–electrolyte couple. The chemical structures were confirmed via Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and UV–vis spectroscopy. Electrochromic and spectroelectrochemical properties of poly(TAPE‐co‐NMPy) [P(TAPE‐co‐NMPy)] were investigated. Results showed that the copolymer revealed color change between light yellow and green upon doping and dedoping of the copolymer, with a moderate switching time. Furthermore, as an application, dual‐type absorptive/transmissive polymer electrochromic device (ECD) based on poly(TAPE‐co‐NMPy) and poly(3,4‐ethylene dioxythiophene) (PEDOT) have been assembled, where spectroelectrochemistry, switching ability, stability, and optical memory of the ECD were investigated. Results showed that the device exhibited good optical memory and stability with moderate switching time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1988–1994, 2006     

D-A type hybrid polymers based on EDOT and various benzodiazoles for electrochromic materials

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 (t_c = 1.6 s, t_b = 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.     

Functional polymers for colloidal applications. VII. Aggregate formation of lipophile-modified polyacrylates in aqueous solutions

Water-soluble copolymers, poly(dodecyl acrylate–coacrylic acid) (PDA), are synthesized by copolymerizing different ratios of dodecyl–acrylate/acrylic acid. Their aqueous solutions are transparent. The plots of I₁/I₃ (the intensity ratio of pyrene emission at 374 nm and 385 nm) and of surface tension as a function of polymer concentrations are combined to verify the existence of the aggregates of PDAs. It is found that the aggregations begin to form at concentrations below that of the polymer transfer to the air–water interface. The plots of I₁/I₃ as a function of polymer concentration shows that the polymers with a higher ratio of dodecyl acrylate form polymer aggregates at lower concentrations. The hydrophobicity of the inner core of polymer aggregates is close to that of sodium dodecyl sulfate (SDS). Polymer solutions of PDA 30, PDA 30L, and PDA 15, show significant solubilization ability to pyrene. (The molar ratio of dodecyl acrylate/total acrylates is 30%, 30%, and 15% for PDA 30, PDA 30L, and PDA 15, respectively. L, low molecular weight.) The solubilization ability increases with the increase in polymer concentration and degree of substitution of dodecylamine. The intensity ratio of the excimer emission to monomer emission of pyrene (I_e/I_m) increases with increasing polymer concentration, roughly parallel to the increase in the amount of pyrene solubilized. However, the I_e/I_m at a fixed pyrene concentration (I_e/I) decreases with increasing polymer concentration. These phenomena are interpreted in terms of the amount of pyrene solubilized and the size and concentration of the polymer aggregates. © 1993 John Wiley & Sons, Inc.     

Diffuse color patterning using blended electrochromic polymers for proof‐of‐concept adaptive camouflage plaques

A study using three different pairs of electrochromic polymers (ECPs) synthesized onto plaques by means of a modified vapor phase polymerization (VPP) technique is presented. Restriction of the respective polymerization times, allowed both faster and slower polymerizing monomers to be controlled, and produced blended plaques with visually diffuse interfaces. The ECPs within the blended plaques retain their individual electrochromic behavior and when encapsulated into an electrochromic device, show outstanding optical switching performance with little degradation evident over 10,000 cycles, coupled with a switching time of the order of 1 second. Blends also allow multiple diffuse color changes within an electrochromic device, due to the difference in oxidation potentials of the individual ECPs, making them candidates for adaptive camouflage use. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42158.     

Electropolymerization of high quality electrochromic poly(3-alkyl-thiophene)s via a room temperature ionic liquid

Electrochemical polymerization in a room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF₆), has been used to prepare electrochromic poly(3-methylthiophene) (PMeT) and its more attractive derivatives: poly(3-hexylthiophene) (PHexT) and poly(3-octylthiophene) (POcT). Spectroelectrochemistry and electrochromic properties of the resulting polymers were characterized using various experiment techniques in [BMIM]PF₆/CH₃CN (1:1, v/v) solution. The thin films were bright red, orange red and orange yellow at its fully reduced state for PMeT, PHexT and POcT, respectively. After oxidization of these undoped polymers, the films underwent reversible change to the bright blue, blue or black blue form. These poly(3-alkylthiophene)s (PMeT, PHexT and POcT) films exhibit high chromatic contrast (46, 45 or 39%), comparative switching times (1.1, 1.4 or 1.9 s), great electrochromic efficiency (250, 220 and 230 cm² C⁻¹) and long-term switching stability. High quality electrochromic polymers were provided for the use of commercially available thiophene monomers, avoiding the use of other custom synthesized monomers.     

Indolo[3,2-b]carbazole-based poly(arylene ethynylene)s through Sonogashira coupling for optoelectronic and sensing applications

Two indolo[3,2-b]carbazole (ICZ)-based polymers have been designed and synthesized using Sonogashira cross-coupling based on dibromoindolo[3,2-b]carbazoles and 2,7-diethynylfluorene or 9,10-diethynylanthracene. The 2, 8 positions of the ICZ moiety has been used for the bridging of arylene ethynylene structure to form the polymer backbone. The characterization has been done by Fourier transform infrared, proton nuclear magnetic resonance, ultraviolet–visible and (UV–vis) fluorescence spectroscopic methods. The polymers, moderately soluble in aprotic and chlorinated solvents, have been found to possess thermal stability above 300°C. The band gap examinations, executed through cyclic voltammetry and complemented by UV–vis studies, indicated their semiconducting nature and the possibility for their utilization for the fabrication of polymer solar cells and for optical switching applications. Interestingly, the new diethynylindolocarbazole systems have been found to act as Bronsted acid sensors as well as a Hg²⁺ receptors. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46940     

Electrochromic properties of some bis‐chalcone derivatives‐based nanofibers

Two bis‐chalcone derivatives, (2E,6E)‐2,6‐bis[(thiophen‐2‐yl)methylene]cyclohexanone ( C1 ) and (2E,6E)‐2,6‐bis[(furan‐2‐yl)methylene]cyclohexanone ( C2 )‐based electrochromic (EC) nanofibers were produced in the presence of poly(methyl methacrylate) (PMMA) as supporting polymer using the electrospinning technique. The scanning electron microscopy (SEM) and energy dispersive X‐ray spectroscopy were used to examine morphology and chemical compositions of nanofibers before and after stability test. SEM images of the obtained smooth and bead‐free nanofibers before the stability test showed that both bis‐chalcone derivatives were homogeneously dispersed on the surface of the electrospun nanofibers. Nanofibers of bis‐chalcone derivatives were characterized with Fourier‐transform infrared spectroscopy. The electrochemical and EC properties of these bis‐chalcone derivatives were investigated. The C1 ‐PMMA nanofiber‐based electrochromic device (ECD) showed higher ΔT_max (41.47%) than that of the C2 ‐PMMA nanofiber‐based ECD (4.67%) during coloration/bleaching at 715 nm. The switching times for coloration and bleaching of C1 ‐PMMA nanofiber‐based ECD were found to be 4.42 and 1.12 s, respectively, and the coloration efficiency was 136.18 cm²/C. Repeated cyclic voltammograms and 1000 cycles of chronoamperometric measurements of the bis‐chalcone derivatives indicated that ECDs have long‐term redox stability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46010.     

Nonaqueous lithium/pyromellitic dianhydride cell

The new lithium/1 M LiClO₄ propylene carbonate/pyromellitic dianhydride (PDA) cell and the improved Li/PDA cell are presented. The Li/PDA cell system has an open circuit voltage of 3.1–3.2 V, and 0.246 Ah g^?1 theoretical capacity, which is based on two-electron transfer. When the pyromellitic acid (PA), which is insoluble in the electrolyte, is added in PDA cathode as proton donor, the specific capacity is roughly two times than that of PDA. The cathode of such improved Li/PDA cell consists of 42 wt% of PDA, 18 wt% of PA and 40 wt% of acetylene black. Such improved Li/PDA cell has about 1300 Wh kg^?1 of energy density.The cell performance of the improved Li/PDA cell is examined, and the self-discharge test is also done and proved the capacity loss to be negligible during two weeks of storage in spite of the solubility of PDA (0.07 mol l^?1) in an electrolyte solution.     

Synthesis and Characterization of a New Fluorine‐Containing Polybenzimidazole (PBI) for Proton‐Conducting Membranes in Fuel Cells

A new type of fluorine‐containing polybenzimidazole, namely poly(2,2′‐(2,2′‐bis(trifluoromethyl)‐4,4′‐biphenylene)‐5,5′‐bibenzimidazole) (BTBP‐PBI), was developed as a candidate for proton‐conducting membranes in fuel cells. Polymerization conditions were experimentally investigated to achieve high molecular weight polymers with an inherent viscosity (IV) up to 1.60 dl g^–1. The introduction of the highly twisted 2,2′‐disubstituted biphenyl moiety into the polymer backbone suppressed the polymer chain packing efficiency and improved polymer solubility in certain polar organic solvents. The polymer also exhibited excellent thermal and oxidative stability. Phosphoric acid (PA)‐doped BTBP‐PBI membranes were prepared by the conventional acid imbibing procedure and their corresponding properties such as mechanical properties and proton conductivity were carefully studied. The maximum membrane proton conductivity was approximately 0.02 S cm^–1 at 180 °C with a PA doping level of 7.08 PA/RU. The fuel cell performance of BTBP‐PBI membranes was also evaluated in membrane electrode assemblies (MEA) in single cells at elevated temperatures. The testing results showed reliable performance at 180 °C and confirmed the material as a candidate for high‐temperature polymer electrolyte membrane fuel cell (PEMFC) applications.     

Color naming in Italian language

The present study investigated Italian basic color terms (BCTs). It is an extension of our previous work that explored Italian basic color categories (BCCs) using a constrained color‐naming method, with 11 Italian BCTs allowed, including blu for naming the BLUE area. Since a latter outcome indicated a categorization bias, here monolexemic color‐naming method was employed, enabling also use of azzurro, deeply entrenched Italian term that designates light blue. In Experiment 1, colors (N = 367), sampling the Munsell Mercator projection, were presented on a CRT; color names and reaction times of vocalization onset were recorded. Naming consistency and consensus were estimated. Consistency was obtained for 12 CTs, including the two blue terms; consensus was found for 11 CTs, excluding rosso “red.” For each consensus category, color with the shortest response time was considered focal. In Experiment 2, consensus stimuli (N = 72) were presented; on each trial, observers indicated the focal color (“best example”) in an array of colors comprising a consensus category. For each of the 12 Italian CCs, centroid was calculated and focal color (two measures) estimated. Compared to English color terms, two outcomes are specific to Italian color naming: (i) naming of the RED‐PURPLE area is highly refined, with consistent use of emergent non‐BCTs; (ii) azzurro and blu both perform as BCTs dividing the BLUE area along the lightness dimension. The findings are considered in the framework of the weak relativity hypothesis. Historico‐linguistic, environmental, and pragmatic communication factors are discussed that conceivably have driven the extension of the BCT inventory in Italian. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 402–415, 2016     

A novel electrochromic polymer containing triphenylamine derivative and pyrrole

A novel conducting polymer was successfully synthesized via electropolymerization of N¹,N⁴-bis(4-(1H-pyrrol-1-yl)phenyl)-N¹,N⁴-diphenylbenzene-1,4-diamine (DPTPA). This polymer film exhibited six various colors under different potentials. Besides, this polymer film showed high optical contrast (41% at 852 nm, 52% at 617 nm) and fast switching time (1.3 s at 410 nm, 1.4 s at 852 nm and 0.6 s at 617 nm). Cyclic voltammogram and electro-optical study showed that the polymer film has a stable and well-defined reversible redox process as well as electrochromic behavior.     

Neutral state colorless electrochromic polymer networks: Spacer effect on electrochromic performance

A series of carbazole-based monomers and their corresponding polymers with various spacer units were synthesized and coated onto ITO-glass surface via an electrochemical cross-linking process. All carbazole-based polymers exhibited multi-electrochromic behavior thanks to two separate oxidation processes. All materials were characterized by FT-IR, ¹H NMR, GPC, DSC, UV–vis, Florescence and CV. In addition, electrochromic properties of the cross-linked polymer films were investigated via spectro-electrochemical measurements. The colorless films were converted to yellowish green and greenish blue colors at the anodic regime. The results indicate that the spacer unit between the carbazole unit and the polymer backbone has a great impact on the optical and electrochemical properties and also on the electrochromic performance of these polymers. PVBEC with benzyloxy based spacer exhibits a high contrast ratio (ΔT% = 55 at 690 nm), a faster response time of about 2.1 s, a higher coloration efficiency (331 cm² C⁻¹) and a better stability (retains its performance by 94.3% even after 1000 cycles).     

Purple red and luminescent polyiminoarylenes containing the 1,4-diketo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DPP) chromophore

New DPP-containing polyiminoarylenes were prepared from 1,4-diketo-2,5-dihexyl-3,6-di(4′-bromophenyl)pyrrolo[3,4-c]pyrrole and various arylamine derivatives using palladium-catalyzed amination reactions. The arylamine comonomers were aniline (ANI), t-butylaniline (TBA), 2-aminoanthracene (AAN), 1-aminopyrene (APY) and N,N′-diphenyl-p-phenylenediamine (PDA). Purple red polymers with good solubility in common organic solvents and molecular weights between 4.4 and 35.8 kDa were obtained. Polymer solutions were readily fluorescent with quantum yields between 19 and 62%, while solution-cast films only showed a weak fluorescence. All polymers exhibit low band gaps of approximately 1.9 eV. Cyclovoltammetric studies indicate quasireversible oxidation for polymers with TBA, APY and PDA as comonomer units, and quasireversible reduction for the polymer with AAN comonomer unit. Polymers with APY and PDA comonomer units are electrochromic and can be switched between red in the neutral and greenish grey in the oxidized state.     

Synthesis and spectroelectrochemistry of dithieno(3,2‐b:2′,3′‐d)pyrrole derivatives

New π‐conjugated polymers containing dithieno(3,2‐b:2′,3′‐d)pyrrole (DTP) were successfully synthesized via electropolymerization. The effect of structural differences on the electrochemical and optoelectronic properties of the 4‐[4H‐dithieno(3,2‐b:2′,3′‐d)pyrrol‐4‐yl]aniline (DTP–aryl–NH₂), 10‐[4H‐dithiyeno(3,2‐b:2′,3′‐d)pirol‐4‐il]dekan‐1‐amine (DTP–alkyl–NH₂), and 1,10‐bis[4H‐dithieno(3,2‐b:2′,3′‐d)pyrrol‐4‐yl] decane (DTP–alkyl–DTP) were investigated. The corresponding polymers were characterized by cyclic voltammetry, NMR (¹H‐NMR and ¹³C‐NMR), and ultraviolet–visible spectroscopy. Changes in the electronic nature of the functional groups led to variations in the electrochemical properties of the π‐conjugated systems. The electroactive polymer films revealed redox couples and exhibited electrochromic behavior. The replacement of the DTP–alkyl–DTP unit with DTP–aryl–NH₂ and DTP–alkyl–NH₂ resulted in a lower oxidation potential. Both the poly(10‐(4H‐Dithiyeno[3,2‐b:2′,3′‐d]pirol‐4‐il)dekan‐1‐amin) (poly(DTP–alkyl–NH₂)) and poly(1,10‐bis(4H‐dithieno[3,2‐b:2′,3′‐d]pyrrol‐4‐yl) decane) (poly(DTP–alkyl–DTP)) films showed multicolor electrochromism and also fast switching times (<1 s) in the visible and near infrared regions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40701.