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A neutral state colorless phosphazene/carbazole hybride dendron and its electrochromic device application
(Elsevier Science Sa, 2015) Sezgin, Meryem; Özay, Özgür; Koyuncu, Sermet; Ozay, Hava; Koyuncu, Fatma Baycan
In this work, a new phosphazene/carbazole hybride dendron (PC) was synthesized and then directly coated onto ITO glass surface to provide a dendritic polymer network, poly-(PC), by using potentiodynamic electrochemical process. Structure of dendron was identified by FT-IR, H-1 and P-31 NMR, and also TOF-MS analyses. The optical and electrochemical properties of PC and its electrochemical crosslinked product were investigated by using UV-vis absorption, fluorescence and CV techniques. A neutral, colorless electrochromic device was constructed in the sandwich configuration [indium tin oxide (ITO)coated glass/anodically coloring material (poly-(PC))//gel electrolyte//cathodically coloring material (PEDOT)/ITO-coated glass] and revealed a short response time (about 0.5 s), high coloration efficiency (981 cm(2) C-1) and high redox stability. (C) 2015 Elsevier B.V. All rights reserved.
A new conducting polymer of 2,5-bis(2-thienyl)-1H-(pyrrole) (SNS) containing carbazole subunit: Electrochemical, optical and electrochromic properties
(Elsevier Science Sa, 2009) Koyuncu, Sermet; Zafer, Ceylan; Sefer, Emre; Koyuncu, Fatma Baycan; Demic, Serafettin; Kaya, İsmet; Ozdemir, Eyup
We report here the synthesis of a new electroactive monomer 3,6-di-tert-butyl-[4-(2,5-di-2-thienyl-1H-pyrrol-1-yl)phenyl]-9H-carbazole in five steps and polymerization of this monomer by two different procceses: Kumada Coupling and electro-oxidative. The product obtained by chemical polymerization exhibits a high thermal stability and narrow molecular weight distribution. While, in the UV-vis absorption spectrum of monomer the absorption peaks appear at 338 nm, the chemically synthesized polymer absorbs at 428 nm with 90 nm red shift. Cyclic voltammogram of monomer shows two separate oxidation processes which reflect the first oxidation at +0.84 V and a second one at +1.43 V. When the polymeric film prepared by electrochemical process was subjected to a repeated cyclic scan between -0.2V and +1.0V, it switches among three different colors (orange, green and blue). The oxidation and reduction response times were calculated as 2.0 s for this polymer film and exhibits high redox stability. The results anticipate that this kind of polymers can be used for designing electrochromics based on the use of one molecule for the generation of three basic colors (RGB). (C) 2009 Elsevier B.V. All rights reserved.
A new donor-acceptor carbazole derivative: Electrochemical polymerization and photo-induced charge transfer properties
(Elsevier Science Sa, 2011) Koyuncu, Fatma Baycan; Koyuncu, Sermet; Ozdemir, Eyup
A new donor-acceptor carbazole derivative containing N-2-(2-ethylhexyl)-1,8-napthalimide as acceptor pendant was synthesized at three steps and directly coated on to ITO glass surface by using electro-chemical process. Subsequently, electrochemical co-polymerization of this monomer was carried out by using 3,4-ethylenedioxythiophene (EDOT) as co-monomer to give electrochromic polymer film. Spectro-electrochemical studies indicated that co-polymer films exhibit relatively lower band gap than that of homo-polymer. Consequently, photo-induced energy and charge transfer properties from the donor-carbazole to naphthalimide-acceptor were studied by using cyclic voltammetry, UV-vis absorption and emission spectroscopy. (C) 2011 Elsevier B.V. All rights reserved.
A New Donor-Acceptor Double-Cable Carbazole Polymer with Perylene Bisimide Pendant Group: Synthesis, Electrochemical, and Photovoltaic Properties
(John Wiley & Sons Inc, 2009) Koyuncu, Sermet; Zafer, Ceylan; Koyuncu, Fatma Baycan; Aydin, Banu; Can, Mustafa; Sefer, Emre; Ozdemir, Eyup
We report here electrochemical synthesis of novel soluble donor-acceptor (D-A) polymer with suitably functionalized perylenetetracarboxylic diimide dye derivative covalently linked to carbazole moiety (Cbz-PDI). The band gap, E, was measured using UV-Vis spectroscopy and compared with that obtained by cyclic voltammetry (CV). Efficient intramolecular electron transfer from carbazole-donor to perynediimide-acceptor leads to remarkable fluorescence quenching of the perylene core. Furthermore, spectroelectrochemical property and surface morphology of the polymer film were investigated. Characteristic monoanion and dianion radical bands on the UV-Vis absorption spectra attributed to the electrochemical reduction of the neutral polymer were observed. During the reduction process, red color of the film turned into blue and violet, respectively. Finally, the photovoltaic performance of the D-A double-cable polymer was checked and nearly 0.1% electrical conversion efficiency is obtained under simulated AM 1.5 solar light with 100 mW/cm(2) radiation power. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6280-6291, 2009
A new imine coupled pyrrole-carbazole-pyrrole polymer: Electra-optical properties and electrochromism
(Elsevier Sci Ltd, 2010) Is, Ozde Deniz; Koyuncu, Fatma Baycan; Koyuncu, Sermet; Ozdemir, Eyup
In this study, imine bond coupled pyrrole carbazole pyrrole monomers were synthesized in four steps and then directly polymerized onto ITO/glass surface via potentiodynamic electrochemical process. Electrochemical and optical bad gap of these monomers and polymers were calculated by using cyclic voltammetry and UV-Vis absorption spectroscopy. Conductivity of the polymers with different alkyl side-chain was determined by using four point probe technique. Length of the side-alkyl chain influence iodine doping and also conductivity of polymers. As a result of the spectroelectrochemical measurements, the orange color of film changed to green color with applied potential and the polymer was found to be suitable material for electrochromic applications. (C) 2010 Elsevier Ltd. All rights reserved.
A new ITO-compatible side chain-functionalized multielectrochromic polymer for use in adaptive camouflage-like electrochromic devices
(Elsevier Science Bv, 2018) Koyuncu, Sermet; Koyuncu, Fatma Baycan
In this study, a new electroactive monomer, 3-(244-(2,5-di-2-thienyl-1H-pyrrol-1-yl)phenyl]ethyl-thio)propanoic acid (SNSPA), was synthesized and then deposited onto the ITO/glass surface by an electrochemical process. When positive potentials were applied on the polymer film of SNSPA, the film at the neutral state turned from orange to green (0.6 V) and then to blue (1.1 V) because of the presence of polaronic and bipolaronic species on the SNS main chain of the polymer. At the last stage, a complementary electrochromic device was constructed by using poly(SNSPA) as the anode layer and PEDOT:PSS as the cathode layer. A fast response time (about 0.5 s) and a high stability of about 98% were obtained at the end of 1000 cycles. The capability of the proposed polymer to undergo reversible color change among brown, green, and blue is a significant property for use as an adaptive camouflage material for all conditions of sand, forest, and sea for military applications.
A new low band gap electrochromic polymer containing 2,5-bis-dithienyl-1H-pyrrole and 2,1,3-benzoselenadiazole moiety with high contrast ratio
(Elsevier Sci Ltd, 2011) Koyuncu, Fatma Baycan; Sefer, Emre; Koyuncu, Sermet; Ozdemir, Eyup
A new low band gap electrochromic polymer containing of 3-(2,5-di-2-thienyl-1H-pyrrol-1-yl)-9-ethyl-9H-carbazole (SNSC) and 2,1,3-benzoselenadiazole (BSe) moiety has been reported. Structural identification of initial compounds and product were carried out by using FT-IR and H-1 NMR spectroscopy results. The resulting polymer, poly(SNSC-BSe), was completely soluble in various common organic solvents and its weight-average molecular weight (M-w) were 9420 (PDI: 1.22). According to AFM results, the RMS (root mean surface) roughness of poly-(SNSC-BSe) was found to be 48.6 nm. Besides, the thermogravimetric analysis presented that the poly(SNSC-BSe) is moderately stable against to thermal effect with the initial degradation temperature at 182 degrees C. The lowest energy transition band maxima of poly(SNSC-BSe) was 498 nm in thin film and the optical band gap calculated from the onset wavelength of the optical absorption was 1.77 eV. On the other hand, the electrochemical band gap calculated from oxidation and reduction onset values was 1.60 eV, respectively. Finally, the electrochromic performance of the polymer film represents a high contrast ratio in the NIR region (51%), fast response time of about 1 s, high coloration efficiency (274 cm(2) C-1) and retained its performance by 94.6% even after 1000 cycles. (C) 2011 Elsevier Ltd. All rights reserved.
A new multi-electrochromic 2,7 linked polycarbazole derivative: Effect of the nitro subunit
(Elsevier, 2011) Koyuncu, Fatma Baycan; Koyuncu, Sermet; Ozdemir, Eyup
A new poly-2,7-di-2-thienyl-9H-carbazole derivative (poly(TCT-N)) bearing nitro (-NO2) subunit has been reported. The electrochemical and optical properties of TCT-N monomer and its polymer have been compared to the 9-phenyl-2,7-di-2-thienyl-9H-carbazole (TCT) standard molecule. Cyclic voltammetry revealed that TCT-N and TCT have excellent polymerization activity; due to extended conjugation with the attached thiophene unit and also their low oxidation potentials. The oxidation potential of TCT-N is higher than that of TCT, because of electro-withdrawing effect of -NO2 moiety. Besides, the TCT-N polymeric film prepared via electrochemical process exhibits a multi-electrochromic behavior compared with TCT standard molecule. The electroactive orange color of poly-TCT-N film converted respectively to green, turquoise and dark blue upon applied positive potentials. Consequently, the polymeric electrochrome exhibits multi-electrochromic behavior, high redox stability, high coloration efficiency and reasonable response time for electrochromic applications. (C) 2011 Elsevier B.V. All rights reserved.
A New Near-Infrared Switchable Electrochromic Polymer and Its Device Application
(Wiley, 2010) Sefer, Emre; Koyuncu, Fatma Baycan; Oguzhan, Eda; Koyuncu, Sermet
A new near-infrared switchable electrochromic polymer containing carbazole pendant (poly-SNSC), synthesized by electrochemical polymerization of 2,5-bis-dithienyl-1H-pyrrole (SNS) main chain, has been prepared. The electrochemical and optical properties of SNSC monomer and its polymer have been investigated. Because of having two different electro-donor moieties; that is, carbazole and SNS, SNSC gave two separate electrochemical oxidation and also light brown color of the film in the neutral state turn into gray on oxidation. An electrochromic device, contructed in the sandwich configuration [indium tin oxide (ITO)-coated glass/anodically coloring polymer (poly-SNSC)//gel electrolyte//cathodically coloring polymer (PEDOT)/ITO-coated glass] and exhibited a high coloration efficiency (1216 cm(2) C-1), a very short response time (about 0.3 s), low driving voltage, and a high redox stability. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4419-4427, 2010
A new processable donor-acceptor polymer displaying neutral state yellow electrochromism
(Elsevier Sci Ltd, 2013) Oguzhan, Eda; Bilgili, Hakan; Koyuncu, Fatma Baycan; Ozdemir, Eyup; Koyuncu, Sermet
We report here the synthesis of a new solution processable neutral state yellow polymeric electrochromic material containing 2,5-bis-dithienyl-1H-pyrrole (SNS)-donor and 1,8 naphthalimide-acceptor (SNS-NI) as a subunit. The electrochemical and optical properties were investigated via cyclic voltammetry (CV), UV Vis absorption and fluorescence emission measurements, respectively. Besides, electrochromic performance of poly(SNS NI) has been compared to the both the film preparation method and poly(1-phenyl-2,5-dithiophen-2-ylpyrrole) [poly(SNS-P)] as a standard polymer. In the poly(SNS-NI), yellow color of the polymer film at neutral state converted to green and then dark blue upon the polymer film fully oxidized in the positive regime. SNS NI polymer film prepared via spin casting process exhibits a high contrast ratio in the near-IR region (Delta T% = 56% at 890 nm), a response time of about 1 s, high coloration efficiency (299 cm(2) C-1) and retained its performance by 98.6% even after 5000 cycles. Finally, the results clearly indicate that both electronic nature of the molecule and film preparation method have a major impact on electrochromic performance of these polymers. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.
A novel donor-acceptor polymeric electrochromic material containing carbazole and 1,8-naphtalimide as subunit
(Pergamon-Elsevier Science Ltd, 2010) Koyuncu, Fatma Baycan; Koyuncu, Sermet; Ozdemir, Eyup
We report here the synthesis of a novel polymeric electrochromic material containing carbazole (Cbz)-donor and 1,8-napthalimide-acceptor as subunit. The band gap E-g was measured using UV-vis spectroscopy and compared with that obtained by cyclic voltammetry (CV). Due to intramolecular electron transfer from Cbz-donor to 1,8-napthalimide-acceptor, the fluorescence quenching was observed. When the spectro-electrochemical and electrochromic properties of polymer film were investigated, various tones of green color were obtained on the polymeric film. In the positive regime, the polymer film obtained thereby is dark green resulting from the association of carbazolylium cation radicals at oxidized state and then it can be bleached by electrochemical reduction. Besides, in the negative regime, yellowish green color of film converted to blue attributed to reduction of the 1,8-napthalimide moiety. Finally, the polymeric electrochromic exhibits multi-electrochromic behavior, high redox stability, high coloration efficiency and reasonable response time. (C) 2010 Elsevier Ltd. All rights reserved.
An ambipolar electrochromic polymer based on carbazole and naphthalene bisimide: Synthesis and electro-optical properties
(Pergamon-Elsevier Science Ltd, 2012) Koyuncu, Fatma Baycan
In this study, an ambipolar polymeric electrochromic material bearing naphthalene bisimide and carbazole derivative (NBIC) was synthesized and then directly polymerized onto ITO/glass surface via potentiodynamic electrochemical process. The electrochemical and optical properties revealed that the charge transfer from carbazole-donor to naphthalene bisimide-acceptor at the ground state. When the spectro-electrochemical properties of the polymer film were investigated, various colors were obtained due to ambipolar redox behavior at both cathodic and anodic regime. In the positive regime, the polymer film exhibits two reversible oxidation waves and transparent color of the film turned into green and then turquoise resulting from the association of polaronic and bipolaronic species from carbazolylium cation radicals. Besides, in the negative regime, transparent color of the film converted to reddish brown attributed to two electron stepwise reduction of the naphthalene bisimide moiety. Finally, the polymeric electrochrome exhibits multi-electrochromic behavior, reasonable redox stability, coloration efficiency and reasonable response time. (C) 2012 Elsevier Ltd. All rights reserved.
Donör akseptör tipi karbazol içeren iletken polimerlerin sentezi ve elektrokromik özelliklerinin incelenmesi
(Çanakkale Onsekiz Mart Üniversitesi, 2011) Koyuncu, Fatma Baycan; Özdemir, Eyüp
Bu tez çalışmasında karbazol içeren donör-akseptör tipi orjinal elektroaktif monomer sentezlenmiş ve elektrokimyasal yolla ITO/Cam yüzeyine polimerleştirilmiştir. Sentezlenen tüm çıkış bileşiklerinin ve sonuç ürünlerinin yapılarının belirlenmesi 1H-NMR ve FT-IR spektrofotometre ölçümleri ile yapılmıştır. Bileşiklerin optik band boşluğu değeri UV-Vis absorbsiyon spektrumlarından, elektrokimyasal band boşluğu değeri ise döngüsel voltametri (CV) ölçümlerinden hesaplanmış, UV-floresans ölçümleri alınarak, UV-Vis ve CV ölçümleriyle beraber değerlendirilmesi sonucunda elektron-enerji transfer mekanizmaları belirlenmiştir. Son aşamada, ITO/Cam yüzeyine elektrokimyasal yolla kaplanan polimerlerin elektrokromik davranışları, spektro-elektrokimyasal ölçümler sonucunda belirlenmiş ve yapıda donör ve akseptör gruplar bulunmasından dolayı, uygulanan pozitif ve negatif potansiyelde bağımsız olarak hareket ederek, çok geniş bir renk skalasının aynı polimer film üzerinde, farklı potansiyellerde gözlenebilmesi mümkün olabilmiştir. Kinetik çalışma sonucunda, elektrokromik polimerlerin yükseltgenme indirgenme cevap zamanları ve kararlılıklarının oldukça iyi olduğu saptanmıştır.
Effect of the planar center moiety for a donor-acceptor polymeric electrochrome
(Elsevier Sci Ltd, 2017) Doyranli, Ceylan; Colak, Betul; Lacinel, Gozde; Can, Mustafa; Koyuncu, Fatma Baycan; Koyuncu, Sermet
In this work, phenanthrene centered donor-acceptor monomer; 5,10-bis(4-hexyl-2-thienyl)phenantro [9,10-c][1,2,5]thiodiazole; MES16 was synthesized and then its electrochromic application of corresponding polymer was carried out. 4,7-di(thiophen-2-yl)-2,1,3-benzothiadiazole (TST) was also synthesized as a standard molecule to determine the effect of the planar phenanthrene center on electrochromic performance. Electrochemical properties were elucidated by cyclic voltammetry and then HOMO-LUMO band gaps were calculated by using their oxidation and reduction onset potentials. Finally, electrochromic properties of poly-(MES16) and poly-(TST) were investigated via spectro-electrochemical measurements. DFT calculations exhibit that poly-(MES16) has a high planarity and an intramolecular charge transfer from the polymer backbone-donor to thiadiazole-acceptor subunit. Because of high solid state it it interactions of the poly-(MES16), a good quality film was obtained corresponding to self assembly property planar phenantrene center. Owing to this property, electrochromic performance of poly-(MES16) such as response time, stability and Delta T% were better than the standard poly-(TST). (C) 2016 Elsevier Ltd. All rights reserved.
Electrochemical, optical and electrochromic properties of imine polymers containing thiophene and carbazole units
(Elsevier Science Sa, 2009) Koyuncu, Sermet; Kaya, İsmet; Koyuncu, Fatma Baycan; Ozdemir, Eyup
New imine polymers containing thiophene and carbazole moiety were synthesized by using both chemically oxidative in the presence of FeCl3 and electrochemically oxidative process. While UV-vis, FT-IR, H-1- and C-13 NMR techniques were used for the structural characterization, the number-average molecular weight (M-n), weight-average molecular weight (M-w) and polydispersity index (PDI) values were determined by size exclusion chromatography (SEC). The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energy levels, electrochemical (E-g') and optical band gap (E-g) values were calculated by using the results of cyclic voltammetry and UV-vis absorption spectroscopy measurements, respectively. Spectroelectrochemical measurements were carried out against the changes in the optical properties of conducting polymers upon voltage changed. Also the yellow color of film changed to green color with applied potential. Conductivities of these polymers were determined by using four-point probe technique. It was seen that the conductivities were increased by iodine doping. (C) 2009 Elsevier B.V. All rights reserved.
Electrochromic properties of phenantrene centered EDOT polymers
(Elsevier Sci Ltd, 2017) Colak, Betul; Buyukkoyuncu, Ahmet; Koyuncu, Fatma Baycan; Koyuncu, Sermet
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. (C) 2017 Elsevier Ltd. All rights reserved.
Emissive Conjugated Polymer Networks with Tunable Band-Gaps via Thiol-Ene Click Chemistry
(Amer Chemical Soc, 2012) Koyuncu, Fatma Baycan; Davis, Andrew R.; Carter, Kenneth R.
A series of cross-linked thin films were prepared via thiol-ene click chemistry from 4-phenylethenyl end-capped tunable band gap conjugated polymers with different photoemission. We demonstrate that the emissive color of PLED devices can be successfully tuned from blue to orange via the use of networks prepared using the thiol-ene click reaction. Electrochemical and optical properties were studied by using cyclic voltammetry, UV-vis absorption, and fluorescence spectroscopy, respectively. PLEDs with configuration of ITO/PEDOT:PSS/x-polymer/Ca:Al were fabricated. The devices had turn-on voltages below 8 V and exhibited multicolor emission. Multi layer devices that demonstrated effective color separation and improved color characteristics compared to blended devices were also prepared.
Fenantren Merkezli Multi Fonksiyonel Donor-Akseptör Tipi Makro Moleku?llerin Sentezi ve Opto-elektronik Uygulamaları
(2016) Koyuncu, Sermet; Zafer, Ceylan; Koyuncu, Fatma Baycan; Can, Mustafa
Bu projede, merkezde du?zlemsel yapıda fenantren moleku?lu? içeren farklı absorbsiyon ve emisyon bandlarına sahip bir dizi elektroaktif makromoleku?l ve polimer (AKD-X ve MGCX) sentezlenmiştir. Sentezlenen çıkış bileşikleri ve nihayi u?ru?nlerin kimyasal yapıları, FT-IR ve 1H-NMR analizleriyle aydınlatılmıştır. AKD-X ve MGC-X elektroaktif moleku?llerin optik özellikleri UV-Vis ve UV-floresas ölçu?mleriyle, elektrokimyasal özellikleri ise döngu?sel voltametri ölçu?mleriyle incelenmiştir. Elde edilen verilerden optik ve elektrokimyasal HOMOLUMO band boşluğu değerleri hesaplanmış, ayrıca temel hal ve uyarılmış haldeki yu?k dağılımları DFT hesaplamalarıyla belirlenmiştir. Elektroaktif özellikteki AKD-X moleku?llerinin Organik boya sensörlu? gu?neş hu?cresi (DSSC) uygulamalarında, MGC-X polimerleri ise elektrokromik uygulamalarda kullanılabileceği elde edilen sonuçlarla ortaya konulmuştur.
Naphthalenediimide bridged D-A polymers: Design, synthesis and electrochromic properties
(Pergamon-Elsevier Science Ltd, 2014) Sefer, Emre; Koyuncu, Fatma Baycan
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 H-1-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. (C) 2014 Elsevier Ltd. All rights reserved.
The New Branched Multielectrochromic Materials: Enhancing the Electrochromic Performance via Longer Side Alkyl Chain
(Amer Chemical Soc, 2011) Koyuncu, Fatma Baycan; Sefer, Emre; Koyuncu, Sermet; Ozdemir, Eyup
We describe the synthesis and structure property relationships of two branched electroactive monomers containing carbazole core, 2,5-di(2-thienyl)-1H-pyrrole, differentiated by the length of side alkyl chains (DSNSC-1 and DSNSC-2). Structural identification of initial compounds and products were carried out by using FT-IR and H-1 and C-13 NMR spectroscopy. The electroactive materials DSNSC-1 and DSNSC-2 were directly coated on to ITO glass surface by using electrochemical polymerization process. The results clearly indicate that the length of side alkyl chain has a major impact on optical and electrochemical properties of these polymers. Poly-DSNC-2 with longer side alkyl chain exhibits a high contrast ratio (Delta T% = 68% at 850 nm), a response time of about 0.8 s, and high coloration efficiency (352 cm(2) C-1) and retained its performance by 97.1% even after 5000 cycles.

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