A new near‐infrared switchable electrochromic polymer and its device application

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 cm² C^–1), a very short response time (about 0.3 s), low driving voltage, and a high redox stability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis and characterization of L‐leucine containing chiral vinyl monomer and its polymer,poly(2‐(methacryloyloxyamino)‐4‐methyl pentanoic acid)

A chiral monomer containing L ‐leucine as a pendant group was synthesized from methacryloyl chloride and L ‐leucine in presence of sodium hydroxide at 4 °C. The monomer was polymerized by free radical polymerization in propan‐2‐ol at 60 °C using 2,2′‐azobis isobutyronitrile (AIBN) as an initiator under nitrogen atmosphere. The polymer, poly(2‐(Methacryloyloxyamino)‐4‐methyl pentanoic acid) is thus obtained. The molecular weight of the polymer was determined to be: M_w is 6.9 × 10³ and M_n is 5.6 × 10³. The optical rotation of both chiral monomer and its polymer varies with the solvent polarity. The amplification of optical rotation due to transformation of monomer to polymer is associated with the ordered conformation of chiral monomer unit in the polymeric chain due to some secondary interactions like H‐bonding. The synthesized monomer and polymer exhibit intense Cotton effect at 220 nm. The conformation of the chain segments is sensitive to external stimuli, particularly the pH of the medium. In alkaline medium, the ordered chain conformation is destroyed resulting disordered random coils. The ordered coiling conformation is more firmly present on addition of HCl. The polymer exhibits swelling‐deswelling characteristics with the change of pH of the medium, which is reversible. The Cotton effect decreases linearly with the increase of temperature which is reversible on cooling. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2228–2242, 2009     

Chiral oxazoline substituted optically active poly(m‐phenylene)s: Synthesis and coupling polymerizations of (S)‐4‐benzyl‐2‐(3,5‐dihalidephenyl) oxazoline using transition metal catalysts

Optically active poly(m‐phenylene)s substituted with chiral oxazoline derivatives have been synthesized by the nickel‐catalyzed Yamamoto coupling reaction of optically active (S)‐4‐benzyl‐2‐(3,5‐dihalidephenyl)oxazoline derivatives (X = Br or I). The structures and chiroptical properties of the polymers were characterized by spectroscopic methods and thermal gravimetric analyses. The polymers showed higher absolute optical specific rotation values than their corresponding monomer, and showed a Cotton effect at transition region of conjugated main chain. The optical activities of the polymers should be attributed to the higher order structure such as helical conformations. Moreover, the helical conformation could be induced by addition of metal salts into polymer solutions. The polymers showed good thermal stabilities, which was attributable to the oxazoline side chains. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Highly stable electrochromic polyamides based on N,N‐bis(4‐aminophenyl)‐N′,N′‐bis(4‐tert‐butylphenyl)‐1,4‐phenylenediamine

A new triphenylamine‐containing aromatic diamine monomer, N,N‐bis(4‐aminophenyl)‐N′,N′‐bis(4‐tert‐butylphenyl)‐1,4‐phenylenediamine, was synthesized by an established synthetic procedure from readily available reagents. A novel family of electroactive polyamides with di‐tert‐butyl‐substituted N,N,N′,N′‐tetraphenyl‐1,4‐phenylenediamine units were prepared via the phosphorylation polyamidation reactions of the newly synthesized diamine monomer with various aromatic or aliphatic dicarboxylic acids. All the polymers were amorphous with good solubility in many organic solvents, such as N‐methyl‐2‐pyrrolidinone (NMP) and N,N‐dimethylacetamide, and could be solution‐cast into tough and flexible polymer films. The polyamides derived from aromatic dicarboxylic acids had useful levels of thermal stability, with glass‐transition temperatures of 269–296 °C, 10% weight‐loss temperatures in excess of 544 °C, and char yields at 800 °C in nitrogen higher than 62%. The dilute solutions of these polyamides in NMP exhibited strong absorption bands centered at 316–342 nm and photoluminescence maxima around 362–465 nm in the violet‐blue region. The polyamides derived from aliphatic dicarboxylic acids were optically transparent in the visible region and fluoresced with a higher quantum yield compared with those derived from aromatic dicarboxylic acids. The hole‐transporting and electrochromic properties were examined by electrochemical and spectro‐electrochemical methods. Cyclic voltammograms of the polyamide films cast onto an indium‐tin oxide‐coated glass substrate exhibited two reversible oxidation redox couples at 0.57–0.60 V and 0.95–0.98 V versus Ag/AgCl in acetonitrile solution. The polyamide films revealed excellent elcterochemical and electrochromic stability, with a color change from a colorless or pale yellowish neutral form to green and blue oxidized forms at applied potentials ranging from 0.0 to 1.2 V. These anodically coloring polymeric materials showed interesting electrochromic properties, such as high coloration efficiency (CE = 216 cm²/C for the green coloring) and high contrast ratio of optical transmittance change (ΔT%) up to 64% at 424 nm and 59% at 983 nm for the green coloration, and 90% at 778 nm for the blue coloration. The electroactivity of the polymer remains intact even after cycling 500 times between its neutral and fully oxidized states. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2330–2343, 2009     

Synthesis of a Stimuli‐Responsive P‐Chiral Polymer with Chiral Phosphorus Atoms and Azobenzene Moieties in the Main Chain

A reaction of the P‐chiral compound (S,S)‐1,2‐bis(boranato(tert‐butyl)methylphosphino)ethane with an azobenzene derivative gave stimuli‐responsive polymers with P‐chiral phosphines in the main chain. This is the first example of a stimuli‐responsive P‐chiral polymer. The polymer isomerized from the trans to the cis form upon UV irradiation and reverted to the trans form reversibly. The polymer was able to coordinate to platinum, and the resulting polymer complex exhibited the Cotton effect owing to the chirality of the phosphorus atoms. The structure of the P‐chiral polymer obtained could be changed reversibly by light and thermal stimuli, and the polymer chain was induced to rotate helically when complexed with transition metals through the chiral phosphorus atoms.     

Preparation of Poly(3,4‐ethylenedioxythiophene) in a Chiral Nematic Liquid‐Crystal Field

Summary: The 3,4‐ethylenedioxythiophene (EDOT) monomer in a chiral nematic liquid‐crystal electrolyte was polymerized by application of a voltage to yield a thin film. Circular dichroism measurements indicated a Cotton effect for the film. Optical texture suggests that the polymer shows a finger‐print texture and a spiral texture similar to that of the chiral nematic phase. This simple method provides a new technique for preparing chiral conducting films in a thermotropic chiral liquid‐crystal field.

Optical micrograph of (R)‐PEDOT* (no polarizer).     

Synthesis and Chain‐Length Dependence of the Electronic Properties of π‐Conjugated Dithieno[3,2‐b:2′,3′‐d]pyrrole (DTP) Oligomers

N‐(2‐ethylhexyl)dithieno[3,2‐b:2′,3′‐d]pyrrole has been prepared and its dimer and trimer have been synthesized by Stille coupling. The electrochemical and optical properties of these compounds have been investigated by cyclic voltammetry, UV–Vis, and fluorescence emission spectroscopies. The obtained results show that these strongly luminescent compounds can be oxidized into stable cation radical and dication state. The analysis of the chain length dependence of the electronic properties indicates that the predicted bandgap of an ideal polymer chain should be considerably smaller than the experimental results reported until now. This difference is discussed in terms of reactivity of the dithieno[3,2‐b:2′,3′‐d]pyrrole (DTP) unit.

     

N‐Arylated 3,5‐Dihydro‐4H‐dinaphtho[2,1‐c:1′,2′‐e]azepines: Axially Chiral Donors with High Helical Twisting Powers for Nonplanar Push–Pull Chromophores

Axially chiral, N‐arylated 3,5‐dihydro‐4H‐dinaphtho[2,1‐c:1′,2′‐e]azepines have been prepared by short synthetic protocols from enantiopure 1,1′‐bi(2,2′‐naphthol) (BINOL) and anilines. Alkynes substituted with two N‐phenyldinaphthazepine donors readily undergo a formal [2+2] cycloaddition, followed by retro‐electrocyclization, with tetracyanoethene (TCNE) to yield donor‐substituted 1,1,4,4‐tetracyanobuta‐1,3‐dienes (TCBDs) featuring intense intramolecular charge‐transfer (CT) interactions. A dicyanovinyl derivative substituted with one N‐phenyldinaphthazepine donor was obtained by a “one‐pot” oxidation/Knoevenagel condensation from the corresponding propargylic alcohol. Comparative electrochemical, X‐ray crystallographic, and UV/Vis studies show that the electron‐donor qualities of N‐phenyldinaphthazepine are similar to those of N,N‐dimethylanilino residues. The circular dichroism (CD) spectrum of a push–pull chromophore incorporating the chiral donor moiety features Cotton effects of exceptional intensity. With their elongated shape and the rigidity of the chiral N‐aryldinaphthazepine donors, these chromophores are effective inducers of twist distortion in nematic liquid crystals (LCs). Thus, a series of the dinaphthazepine derivatives was used as dopants in the nematic LC E7 (Merck) and high helical twisting powers (β) of the order of hundreds of μm^?1 were measured. Theoretical calculations were employed to elucidate the relation between the structure of the dopants and their helical twisting power. For the derivatives with two dinaphthazepine moieties, a strong dependence of the β‐values on the structure and conformation of the linker between them was found.     

A hybrid‐type,chiral π‐conjugated polymer wrapped with polyhedral oligomeric silsesquioxanes

A novel hybrid‐type chiral binaphthyl‐based polyarylene derivative with polyhedral oligomeric silsesquioxanes (POSS) units 2a was prepared by Suzuki–Miyaura coupling polymerization from a chiral (R)‐6,6′‐dibromo‐2,2′‐diPOSS‐substituted 1,1′‐binaphthyl derivative 1a and p‐biphenylene diboronic acid. As a reference, a binaphthyl‐based polyarylene derivative without POSS unit 2b was also prepared. The obtained polymers were studied with thermogravimetric analysis, optical rotations, circular dichroism (CD), ultraviolet‐visible, and photoluminescence (PL) spectra. Gel permeation chromatography measurements of 2a and 2b showed that their number‐average molecular weights were 13,300 and 16,500, respectively. The thermal stability of POSS‐modified polymer 2a (temperature of 10% weight loss; T₁₀ = 380 °C) was extremely high compared with that of polymer without POSS unit 2b (T₁₀ = 335 °C) due to the siliceous bulky POSS segments on the side chains. The specific optical rotation [α]_D was ?66.7° (c 0.06, CHCl₃) for 2a and ?62.3° (c 0.06, CHCl₃) for 2b . The CD spectra showed that these two polymers had very similar and strong Cotton effects. Film polymer 2a showed almost the same PL spectrum as that in dilute CHCl₃ solution, indicating that bulky POSS units strongly suppressed intermolecular aggregation of the π‐conjugated polymer backbone. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6035–6040, 2008     

The preparation of 3,6‐bis(3‐hexylthien‐2‐yl)‐s‐tetrazine and its conjugated polymers

We demonstrated, for the first time, that 3,6‐bis(3‐hexylthien‐2‐yl)‐s‐tetrazine (TTz) with hexyl group at the 3‐position of thiophene rings can be prepared using a modified sulfur‐assisted Pinner synthesis. Although the hexyl group creates large steric hindrance to the tetrazine ring formation reaction, and the reaction under a traditional condition only produces trace amount of the target product, the yield of this reaction under a modified reaction condition using anhydrous hydrazine at 68 °C can reach 65%. Two new copolymers of the resulting TTz and hexyl‐ or 2‐ethylhexyl‐substituted cyclepentadithiophene have been prepared. The polymers show a broader light absorption in film than in solution attributing to the large distribution of effective conjugation length of polymer chain due to the existence of both cis‐ and trans‐orientations of the 3‐hexylthiophene units in the planar polymer chain in solid state. Although the polymers show a narrow band gap and a deep HOMO level, which are desirable for generating an efficient light absorption and a larger open circuit voltage (V_oc) of the resulting solar cell devices, the device performance is not as good as expected. It is attributed to the random distribution of the cis‐ and trans‐conformations along the polymer chain. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.     

Electrochromic material containing unsymmetrical substituted N,N,N′,N′‐tetraaryl‐1,4‐phenylenediamine: Synthesis and their optical,electrochemical, and electrochromic properties

A novel dibromo compound containing unsymmetrical substituted bi‐triarylamine was synthesized. A conjugated polymer was prepared via the Suzuki coupling from the newly prepared dibromo compound and 9,9‐dioctylfluorene‐2,7‐bis(trimethyleneboronate). The glass transition temperature (T_g) of the conjugated polymer was 140 °C, 10% weight‐loss temperatures (T_d10) in nitrogen was 458 °C, and char yield at 800 °C in nitrogen higher than 64%. Cyclic voltammogram of the polymer film cast onto an indium‐tin oxide (ITO)‐coated glass substrate exhibited two reversible oxidation redox couples at 0.70 and 1.10 V versus Ag/Ag⁺ in acetonitrile solution. The polymer films revealed excellent stability of electrochromic characteristics, with a color change from yellow green of the neutral form to the dark green and blue of oxidized forms at applied potentials ranging from 0 to 1.3 V. The color switching time and bleaching time were 4.25 and 7.22 s for 860 nm and 5.51 s and 6.48 s for 560 nm. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1469–1476, 2010     

A novel high‐contrast ratio electrochromic material from spiro[cyclododecane‐1,9′‐fluorene]bicarbazole

A novel electroactive spirocyclododecylfluorene monomer named 2,7‐bis(carbazol‐9‐yl)‐9,9′‐spiro[cyclododecane‐1,9′‐fluorene] (SFC) was synthesized and electrochemically polymerized to give a very stable multi‐electrochromic polymer (poly‐SFC). Two separate oxidation processes were observed for both SFC monomer and poly‐SFC that carries two carbazole units. The polymeric film of poly‐SFC was coated onto ITO/glass surface, and it shows different colors (transparent, yellowish green, green, and dark green) upon stepwise oxidations. An electrochromic device based on poly‐SFC was assembled in the sandwich cell configuration of ITO/poly‐SFC//gel electrolyte//PEDOT/ITO. Poly‐SFC exhibits 90% of transparency at neutral state and a high contrast ratio (ΔT = 58% at 800 nm). This device constructed from it represents a response time of about 1 s, high coloration efficiency (1377 cm² C^–1) and retained its performance by 96.4% even after 1000 cycles. Exhibiting high transparency at neutral state, reversible redox behavior, resistance to overoxidation, and especially high contrast ratio at near IR region can make poly‐SFC be useful and promising candidate for electrochromic applications despite having a relatively slow response time. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010     

New π‐Conjugated polymers containing 4H,4′H‐[1,1′‐Bithieno [3,4‐C]Pyrrole]‐4,4′,6,6′(5H,5′H)‐Tetraone (biTPD) units and their application to thin‐Film transistors and photovoltaic cells

We successfully synthesized new D‐A copolymers that employ 1,10‐bithienopyrrolodione (biTPD), thiophene, and selenophene‐based donor monomeric units. Two polymers, PBTPDEBT and PBTPDEBS , exhibited high degrees of crystallinity and unique polymer chain arrangements on the substrate, which is attributed to their enhanced coplanarity and intermolecular interactions between the polymer chains. Among the thin‐film transistor devices made of PBTPDEBT and PBTPDEBS , the annealed PBTPDEBS device displayed relatively high hole mobility, which was twice that of the PBTPDEBT ‐based device. In addition, an organic photovoltaic device based on a PBTPDEBS :PC₇₁BM blend displayed the maximum power conversion efficiency of 3.85%. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1228–1235     

Substituent effect on supercapacitive performances of conducting polymer‐based redox electrodes: Poly(3′,4′‐bis(alkyloxy) 2,2′:5′,2″‐terthiophene) derivatives

This work reports the synthesis of novel poly(3′,4′‐bis(alkyloxy)terthiophene) derivatives (PTTOBu, PTTOHex, and PTTOOct) and their supercapacitor applications as redox‐active electrodes. The terthiophene‐based conducting polymers have been derivatized with different alkyl pendant groups (butyl‐, hexyl‐, and octyl‐) to explore the effect of alkyl chain length on the surface morphologies and pseudocapacitive properties. The electrochemical performance tests have revealed that the length of alkyl substituent created a remarkable impact over the surface morphologies and charge storage properties of polymer electrodes. PTTOBu, PTTOHex, and PTTOOct‐based electrodes have reached up to specific capacitances of 94.3, 227.3, and 443 F g⁻¹ at 2.5 mA cm⁻² constant current density, respectively, in a three‐electrode configuration. Besides, these redox‐active electrodes have delivered satisfactory energy densities of 13.5, 29.3, and 60.7 W h kg⁻¹ and power densities of 0.98, 1, and 1.1 kW kg⁻¹ with good capacitance retentions after 10,000 charge/discharge cycles in symmetric solid‐state micro‐supercapacitor devices. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 480–495     

Poly(ProDOT‐Et2): A High‐Contrast,High‐Coloration Efficiency Electrochromic Polymer

The synthesis and electrochemical polymerization of 3,3‐diethyl‐3,4‐dihydro‐2H‐thieno‐[3,4‐b][1,4]dioxepine (ProDOT‐Et₂) was performed resulting in a stable electrochromic polymer capable of switching between an absorbing blue neutral state and a highly transmissive sky‐blue oxidized state in sub‐second time frames. High optical switching contrast ratios (up to 75% at λ_max) and high composite coloration efficiencies (505 cm²/C) were measured.     

Synthesis and photovoltaic properties of 2,6‐bis(2‐thienyl) benzobisazole and 4,8‐bis(thienyl)‐benzo[1,2‐B:4,5‐B′]dithiophene copolymers

In an effort to design efficient low‐cost polymers for use in organic photovoltaic cells the easily prepared donor–acceptor–donor triad of a either cis‐benzobisoxazole, trans‐benzobisoxazole or trans‐benzobisthiazole flanked by two thiophene rings was combined with the electron‐rich 4,8‐bis(5‐(2‐ethylhexyl)‐thien‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithiophene. The electrochemical, optical, morphological, charge transport, and photovoltaic properties of the resulting terpolymers were investigated. Although the polymers differed in the arrangement and/or nature of the chalcogens, they all had similar highest occupied molecular orbital energy levels (?5.2 to ?5.3 eV) and optical band gaps (2.1–2.2 eV). However, the lowest unoccupied molecular orbital energy levels ranged from ?3.1 to ?3.5 eV. When the polymers were used as electron donors in bulk heterojunction photovoltaic devices with PC₇₁BM ([6,6]‐phenyl C₇₁‐butyric acid methyl ester) as the acceptor, the trans‐benzobisoxazole polymer had the best performance with a power conversion efficiency of 2.8%. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 316–324     

Asymmetric anionic polymerization of N‐1‐naphthylmaleimide with chiral ligand‐organometal complexes in toluene

Asymmetric anionic homopolymerizations of N‐1‐naphthylmaleimide (1‐NMI) were performed with chiral ligand/organometal complexes to form optically active polymers. Poly(1‐NMI)s obtained with methylene‐bridged bisoxazoline derivatives (Rbox)‐diethylzinc (Et₂Zn) complexes showed high specific optical rotations ([α]) from +152.3 to +191.4°. Circular dichroism spectra of the polymers exhibited a split Cotton effect in the UV absorption‐band region. According to the exciton chirality method, the absolute configuration of the polymer main chain was determined according to the following method: (+)‐poly[N‐substituted maleimides (RMI)] main chains can contain more (S,S)‐ than (R,R)‐configurations. (?)‐Poly(RMI) main chains can contain more (R,R)‐ than (S,S)‐configurations. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3556–3565, 2001     

Synthesis,photoluminescence, and electrochromism of polyamides containing (3,6‐di‐tert‐butylcarbazol‐9‐yl)triphenylamine units

A new carbazole‐derived, triphenylamine (TPA)‐containing aromatic dicarboxylic acid monomer, 4,4′‐dicarboxy‐4″‐(3,6‐di‐tert‐butylcarbazol‐9‐yl)TPA, was synthesized, and it led to a series of electroactive aromatic polyamides with main‐chain TPA and pendent 3,6‐bis(tert‐butyl)carbazole units by reacting it with various aromatic diamines via the phosphorylation polyamidation technique. The polyamides were amorphous with good solubility in many organic solvents and could be solution‐cast into flexible and strong films. They showed high glass‐transition temperatures (282–335 °C) and high thermal stability (10% weight loss temperatures >480 °C). The electroactive polymer films had well‐defined and reversible redox couples with good cycle stability in acetonitrile solutions. The polymer films also exhibited fluorescent and multielectrochromic behaviors. The anodically electrochromic polyamide films had moderate coloration efficiency (～100 cm²/C) and high optical contrast ratio of transmittance change (Δ%T) up to 47% at 813 nm and 48% at 414 nm for the green coloring. After hundreds of cyclic switches, the polymer films still retained good redox and electrochromic activity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis and characterization of main‐chain NLO oligomers and polymer that contain 4‐dialkylamino‐ 4′‐(alkylsulfonyl)azobenzene chromophores

An ω‐amino carboxylic acid monomer that contained a nonlinear optical (NLO) chromophore was prepared by a convergent synthesis. Strategies for selective protection/deprotection of the amino and carboxylic acid functionalities were developed. The protected monomer, 4‐[N‐(4‐benzyloxycarbonyl)butyl‐N‐methylamino]‐4′‐[2″,5″‐bis(decyloxy)‐4″‐(phthalimidomethyl)benzylsulfonyl]azobenzene, could be deprotected selectively or sequentially to give HOOC‐monomer‐N‐phthaloyl, benzyl‐OOC‐monomer‐NH₂, or HOOC‐monomer‐NH₂. Sequential synthesis was performed to yield main‐chain NLO dimers and tetramers. This was accomplished by selective deprotection and dicyclohexylcarbodiimide coupling. The HOOC‐monomer‐NH₂ was polymerized by treatment with diphenylphosphoryl azide to give a main‐chain NLO polyamide. The monomer, dimer, tetramer, and polymer NLO materials were characterized by ¹H, ¹³C, IR, and UV–visible spectroscopy as well as by gel permeation chromatography, differential scanning calorimetry, and elemental analysis. The NLO properties of these materials were measured. Thin films of the oligomers and polymer were prepared by spin casting on indium‐tin oxide coated glass. The second‐order NLO properties of the oligomers and polymer thin films were studied by in situ corona poling/second‐harmonic generation and attenuated total reflection methods. The optimal poling temperatures were significantly lower than the melting temperatures or glass‐transition temperatures of the oligomers and polymer. The poling efficiency increased in the following order: monomer, oligomers, and polymer. An electro‐optic coefficient of 4 pm/V at 1.06 μm was obtained for the polymer. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 546–559, 2000     

Effects of Supporting Electrolytes on Spectroelectrochemical and Electrochromic Properties of Polyaniline‐poly(styrene sulfonic acid) and Poly(ethylenedioxythiophene)‐poly(styrene sulfonic acid)‐based Electrochromic Device

Electrochromic devices are fabricated by using polyaniline (PANI) doped with poly(styrene sulfonic acid) (PSS) as coloring electrodes, poly(ethylenedioxythiophene)‐poly(styrene sulfonic acid) (PEDOT‐PSS) as complementary electrodes, and hybrid polymer electrolytes as gel electrolytes. The device based on LiClO₄‐based electrolyte (weight ratio of PMMA:PC:LiClO₄ = 0.7:1.1:0.3) shows the highest optical contrast and coloration efficiency (333 cm²/C) after 1200 cycles in these devices, and the color changes from pale yellow (?0.5 V) to dark blue (+2.5 V). The spectroelectrochemical and electrochromic switching properties of electrochromic devices are investigated, the maximum optical contrast (ΔT%) of electrochromic device for ITO|PANI‐PSS‖PMMA‐PC‐LiClO₄‐SiO₂‖PEDOT‐PSS|ITO are 31.5% at 640 nm, and electrochromic device based on LiClO₄‐based electrolyte with SiO₂ shows faster response time than that based on LiClO₄‐based electrolyte without SiO₂.