Polypyrrole Color Modulation and Electrochromic Contrast Enhancement by Doping with a Dye

Girotto, Emerson M.; Paoli, Marco-Aurélio De

doi:10.1002/(sici)1521-4095(199807)10:10<790::aid-adma790>3.0.co;2-r

Cited by 63 publications

(51 citation statements)

References 5 publications

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“…121,122 The enhancement and modulation of the color change on indigo carmine insertion into polypyrrole or polypyrrole/dodecylsulfonate films was shown. 123 As expected, the use of indigo carmine as dopant improves the films' electrochromic contrast ratio.…”

Section: Functionalized Electrochromic Polymers and Compositessupporting

confidence: 55%

Electrochromic organic and polymeric materials for display applications

2006

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An electrochromic material is one where a reversible color change takes place upon reduction (gain of electrons) or oxidation (loss of electrons), on passage of electrical current after the application of an appropriate electrode potential. In this review the general field of electrochromism is introduced, with coverage of the types, applications, and chemical classes of electrochromic materials and the experimental methods that are used in their study. The main classes of electrochromic organic and polymeric materials are then surveyed, with descriptions of representative examples based on transition metal coordination complexes, viologen systems, and conducting polymers. Examples of the application of such organic and polymeric electrochromic materials in electrochromic displays are given.

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Section: Functionalized Electrochromic Polymers and Compositessupporting

confidence: 55%

Electrochromic organic and polymeric materials for display applications

2006

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“…The redox charge was measured by chronoamperommetry and controlled by the synthesis charge. In a recent work 3 we have described in details the method of synthesis and electrochromic characterization of PPy-DS-IC. As transparent electrodes, we used ITO-PET (poly(ethylene terphthalate) coated with indium doped tin oxide (I.S.T.…”

Section: Methodsmentioning

confidence: 99%

“…In a recent paper 3 we used a dianionic dye to enhance the optical contrast of polypyrrole. Not only the use of dyes 4 , but other aspects are important: sol-gel deposition film methods 5 , temperature of deposition 6 , counterion color influence 7 , oxygen flow during sputtered films 8 , coating the electrochrome with thin gold or platinum layer 9 , etc.…”

Section: Introductionmentioning

confidence: 99%

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Flexible electrochromic windows: a comparison using liquid and solid electrolytes

Girotto

Paoli

1999

J. Braz. Chem. Soc.

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Neste trabalho foram montados e caracterizados dois dispositivos eletrocrômicos (ou janelas eletrocrômicas) utilizando como materiais opticamente ativos polímeros instrinsecamente condutores. Os materiais usados na montagem foram os mesmos, exceto pelo eletrólito usado. No primeiro foi usado como eletrólito uma solução de carbonato de propileno e no segundo o elastômero poli(epicloridrina-co-oxido de etileno), ambos contendo LiClO4. A condutividade elétrica do eletrólito líquido é aproximadamente duas ordens de grandeza maior (10 -3 S cm -1) do que a do eletrólito sólido e foram obtidos excelentes resultados do ponto de vista eletrocrômico em ambos os casos. A eficiência eletrocrômica em 640 nm foi calculada em 700 C cm -2 para o dispositivo com eletrólito liquido e 360 C cm -2 para o dispositivo montado com eletrólito sólido. O uso de dispositivos eletrocrômicos de estado sólido tem chamado bastante atenção e suas vantagens são discutidas.In the present work, two electrochromic devices (or electrochromic windows) based on intrinsically conducting polymers were assembled and characterized. For both devices, the materials used on the assembling were the same except for the electrolyte layer. In the first, we used as electrolyte a propylene carbonate solution and in the second the elastomer poly(epichlorohydrin-co-ethylene oxide), both containing LiClO4. The conductivity of the liquid electrolyte (10 -3 S cm -1) is approximately two orders of magnitude higher than for the solid electrolyte and we obtained very good electrochromic properties in both cases. The calculated electrochromic efficiency at 640 nm was 700 C cm -2 for the liquid electrolyte device and 360 C cm -2 for the solid state device. Solid state electrochromic windows have been investigated and some of its advantages over windows with liquid electrolytes are discussed.

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“…They are additionally being investigated for use in solar cells, rechargeable batteries, biosensors, electrochromic devices, anti-static coatings and many more [75,[84][85][86][87][88][89][90][91].…”

Section: Polypyrrolementioning

confidence: 99%

A Bio-inspired Excitable Cardiac Cell Membrane from Electroactive Polymers: Ion Transport Studies

Moored

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The heart is an incredibly efficient biological pump, which contracts as a whole from the coordinated effort of millions of excitable cells called cardiac myocytes. These cells are considered excitable since they possess the ability to respond to a threshold activation signal, but only if sufficient time has passed and they have recovered from their previous excitation. Excitable cells also have the capacity to propagate an activation signal to their neighboring cells, and collectively are referred to as an excitable medium. Numerous examples of excitable media exist in nature, including the heart, forest fires, the intestine, nerves, and certain kinds of chemical reactions. Engineered artificial excitable media, however, have never been developed before.The long-term goal of this project, therefore, is to develop the first such artificial excitable medium from an array of artificial excitable cells, called gel-cells. The conceptual design of the gel-cell consists of a thin electroactive ion-gating membrane (polypyrrole), sandwiched between two layers of hydrated polymer (hydrogel) loaded with different concentrations of potassium chloride (KCl aq ) electrolytes. The voltage controlled artificial membrane initially confines ions to the upper chamber of the gelcell, and releases them upon membrane opening into the lower chamber, a process similar to membrane activation in cardiac myocytes. Potassium sensing electrodes embedded throughout the gel-cell provide feedback on the location and concentration of ions within the gel-cell, becoming markers for its activation. The scope of the research presented here was to construct the biomimetic cell membrane portion of the gel-cell, and study ion transport through its assembly.First, the electrochemical response of polypyrrole (PPy) was characterized via cyclic voltammetry, and its membrane morphology and thickness were observed via scanning electron microscopy. Experimentally obtained membrane thickness values were then compared to model predictions, which were subsequently improved by updating membrane density and structure assumptions. Hydrogel pore size approximations were correlated to equilibrium water content calculations, and KCl aq concentrations were quantified using electrochemical impedance spectroscopy. Time-resolved KCl aq flux experiments were performed on PPy membranes in solution, providing real-time concentration profiles of KCl aq as it passes through the membrane. From the parameter space tested, the optimal membrane preparation and gating potentials were selected which produced the highest flux rates. Time-lapse flux experiments (providing piece-wise concentration profiles for KCl aq ) were then performed on PPy membranes in both solution and hydrogel. Ion transport through two nearly identical membranes produced under different deposition conditions (PPy a and PPy b ) were compared in solution. The slightly denser and thicker membrane (PPy b ) produced nearly an order of magnitude higher flux rates than PPy a , suggesting that an active comp...

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Polypyrrole Color Modulation and Electrochromic Contrast Enhancement by Doping with a Dye

Cited by 63 publications

References 5 publications

Electrochromic organic and polymeric materials for display applications

Electrochromic organic and polymeric materials for display applications

Flexible electrochromic windows: a comparison using liquid and solid electrolytes

A Bio-inspired Excitable Cardiac Cell Membrane from Electroactive Polymers: Ion Transport Studies

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