Showing papers on "Electrochromism published in 1980"
Patent•
11 Sep 1980TL;DR: In this article, an infra-red reflecting electrochromic light controlling panel comprising, successively in laminated structure, first transparent plate, a transparent electroconductive film, an interlayer of polymer electrolyte, first tungsten oxide film and second transparent plate.
Abstract: Infra-red reflecting electrochromic light controlling panel comprising, successively in laminated structure, first transparent plate, a transparent electroconductive film, an interlayer of polymer electrolyte, first tungsten oxide film, an infra-red reflecting and electroconductive metal film, second tungsten oxide film and second transparent plate. The first tungsten oxide film is colored when it is applied to negative voltage. The panel can be used as an infra-red reflecting window which regulates the transmission of visible light and solar energy by applying electric field to the first tungsten oxide film.
122 citations
TL;DR: In this paper, the authors proposed a mixture of mixed ionic/electronic conductors for use as electrodes in secondary batteries and electrochromic displays, where charge compensation is achieved by a variation of mobile-electron concentration in the host matrix.
Abstract: Insertion compounds contain a mobile cation of variable concentration over a wide range of solid solution. Charge compensation is achieved by a variation of mobile-electron concentration in the host matrix. Such mixed ionic/electronic conductors are of practical interest as electrodes in secondary batteries and electrochromic displays. Oxides containing transition-metal ions in unusually high valence states can be prepared by room-temperature extraction of mobile cations from such structures. Some properties of the systems Li1-yCoO2 and Na1-yCoO2 are presented.
105 citations
TL;DR: In this article, the authors used a combined gravimetric, coulometric, and reflection spectroscopy analysis of iridium oxide films to determine the oxide state changes, completeness of oxidation, and densities of anodically formed, electrochromic oxide films.
Abstract: Oxidation state changes, completeness of oxidation, and densities of anodically formed, electrochromic iridium oxide films have been determined by combined gravimetric, coulometric, and reflection spectroscopy analyses. The results show that the oxidation state of Ir ions in the oxide is changed from III to IV during the anodic coloration process [0.25 to 1.25V (RHE)], rather than II to IV as previously postulated, and that virtually all Ir ions in the film are accessible for electrochemical oxidation and reduction. The mean density of the oxide film is 2.0g cm−3, as compared to 11.68 for bulk crystalline . The structure of the film was shown by electron microscopy to consist of oxide grains 0.05–0.1 μm in diameter, surrounded by voids. In addition, the presence of a high density of microvoids ~25A in diameter was detected. The highly porous structure of the film permits ready access of the electrolyte to the oxide grains throughout the entire film and facilitates the rapid coloration and bleaching (~40 msec) observed in aqueous electrolytes. The apparent accessibility of all Ir ions in the film also implies rapid transport, within the oxide grains, of the mobile charge‐compensating ions which must be injected and ejected to preserve electroneutrality. Mechanisms of ion and electron transport are discussed.
92 citations
TL;DR: In this paper, the current potential (i•E) curves for the electrochromic process at electrodes were calculated with a digital simulation model which assigns the rate of charge transfer at the oxide/solution interface and the diffusion of hydrogen into the bulk of the film as major variables.
Abstract: Current‐potential (i‐E) curves for the electrochromic process at electrodes were calculated with a digital simulation model which assigns the rate of charge transfer at the oxide/solution interface and the rate of diffusion of hydrogen into the bulk of the film as major variables. The simulated i‐E curves agreed well with experimental ones for different types of films and predicted the observed dependency of current on scan rate. The simulation required knowledge of the form of the electrochemical isotherm, which was obtained experimentally, and adjustment of a charge transfer rate constant, , and the hydrogen atom diffusion coefficient within the film, . The best fit was obtained with and for the films prepared by vacuum evaporation and and for anodic films. Simulated potential step results, which are similar to the experimental curves at longer times but show some discrepancy in the short time region, and concentration profiles are also reported.
84 citations
Patent•
16 Apr 1980TL;DR: In this paper, an electrochromic display device (e.g., ECD) is described, which is stably workable for a long period and shows a long cycle life.
Abstract: The invention relates to an electrochromic display device (referred to as ECD hereinafter) which is stably workable for a long period and shows a long cycle life. The ECD of the invention has its feature in using a counter electrode which comprises a collector composed of a valve effect having metal such as titanium, tantalum, aluminum and the like, the metal being hardly soluble in an electrolyte, and a reactive material on the said collector and electrically connected to the said, collector, the reactive material being selected from reductant of tungsten oxide, iron berlinate and the like and being able to carry out a reversible oxidation reaction at a lower potential than that the said collector carries out an oxidation reaction.
75 citations
TL;DR: In this article, a new class of organic polymeric thin-film electrochromic materials is described, which exhibit good switching speeds (τ⩽100 ms), possess intrinsic memory, and show no chemical degradation or adhesion loss in preliminary life tests.
Abstract: A new class of organic polymeric thin‐film electrochromic materials is described. We show that the new polymer‐modified electrodes change color reversibly in permanent thin‐film form without the electrodeposition characteristics of organic liquid state systems such as the viologens. The polymer films exhibit good switching speeds (τ⩽100 ms), possess intrinsic memory, and show no chemical degradation or adhesion loss in preliminary life tests (104 cycles). It is demonstrated that several important electrochromic parameters can be varied by chemical modification of the polymeric material.
68 citations
TL;DR: In this article, the electrochromic effect of anodic iridium oxide films (AIROF's) in aqueous and nonaqueous electrolytes was examined and it was shown that electrochromism in AIROF's can occur via hydroxide ions, without insertion−extraction of protons from the electrolyte.
Abstract: We examine the electrochromic effect of anodic iridium oxide films (AIROF's) in aqueous and nonaqueous electrolytes All experimental data in aqueous electrolytes are consistent with the hypothesis that electrochromism in AIROF's can occur via hydroxide ions, without insertion‐extraction of protons from the electrolyte We also report new experiments in which electrochromism of AIROF's takes place by insertion‐extraction of anions (OH−, F−, CN−) from nonaqueous electrolytes
63 citations
TL;DR: In this article, the coloration process induced by small changes of the potential across the HxMoO3•electrolyte interface was studied by a photometric method.
Abstract: Coloration by electron diffusion and electrochromism was studied in HxMoO3 amorphous films following the technique of Crandall and Faughnan et al. in HxWO3. The measured diffusion coefficient for electrons was D=7.5×10−4 cm2/sec and the emf of the cell Cu‐In‐glycerol +H2SO4‐HxMoO3‐SnO2‐Cu was measured as a function of x. The dynamics of the coloration process induced by small changes of the potential across the HxMoO3‐electrolyte interface was studied by a photometric method.
54 citations
TL;DR: In this paper, the oxide film grown on a rhodium metal substrate in alkaline solutions by potential multipulsing behaves as a fast two-color electrochromic system.
Abstract: The oxide film grown on a rhodium metal substrate in alkaline solutions by potential multipulsing behaves as a fast two‐color electrochromic system. Reversible yellow dark green or yellow brown‐purple coloration changes are obtained in either solutions. The films suffer very small charge losses after 105 cycles in either electrolytes. The response is faster, but the open‐circuit memory is shorter in the more concentrated alkaline solution. The response time of the Rh oxide film in alkaline solutions is comparable to that of the Ir oxide electrochromic in acid solutions, but the open‐circuit memory is longer in the latter system. A loss of electrochromic activity was found to be caused in both rhodium and iridium oxide films by excessive cathodic pulse potentials.
53 citations
TL;DR: In this paper, it was shown that the high proton conductivity of hydrogen uranyl phosphate tetrahydrate HUO 2 PO 4 ·4H 2 O (HUP) is sufficient to enable an HUP/H x WO 3 electrochromic cell to function as fast as a cell with an acidic solution electrolyte.
TL;DR: Absorbance changes induced by electrical field pulses were studied in osmotically swollen spinach chloroplasts and the interpretation on the basis of the geometry and electrical properties of the material may be summarized.
Patent•
21 Jul 1980TL;DR: In this article, the authors described a layer of electrochromic material in contact with an organic electrolyte resin, with electrode means for changing electro chromic properties of the device by electric field means.
Abstract: Electrochromic devices are described having a layer of electrochromic material, e.g. WO,, in contact with a layer of organic electrolyte resin, with electrode means for changing electrochromic properties of the device by electric field means. The electrolyte resin layer comprises a hydrophilic layer of homopolymer of poly(2-acrylamido-2 -methylpropanesulfonic acid) and in some preferred embodiments may further comprise a thinner layer of less hydrophilic electrolyte resin between the homopolymer and electrochromic layers.
TL;DR: Voltammetric and spectroelectrochemical results are presented for the one-electron reduction of n−heptylviologen dibromide on clean and silane modified, tin oxide, and on indium tin oxide metallized-plastic optically transparent electrodes (MPOTE) as discussed by the authors.
Abstract: Voltammetric and spectroelectrochemical results are presented for the one‐electron reduction of n‐heptylviologen dibromide on clean and silane‐modified, tin oxide, and on indium tin oxide metallized‐plastic optically transparent electrodes (MPOTE). The amount of n‐heptylviologen dibromide reduced and the rate of coloration due to the formation of the cation‐radical film can strongly be influenced by the state of the electrode surface. The initial 200–500 msec of viologen deposition are not mass transport controlled. Calculations for the amount of viologen deposited vary, depending on whether a spectrophotometric or coulometric estimated is used. Spectrophotometric data indicate that the amount of viologen deposited in the first 200 msec of chronoamperometric reduction from a concentrated viologen solution is ca. 10–14 monolayers and is increased at least 60% by the addition of a monolayer of the silane modifier to the electrode surface. In the case of the metallized plastic films, the increase in coloration rate may be attributed to the presence of nonpolar surface groups present at the surface of the conductive film.
TL;DR: In this paper, Malpas et al. used a piezoelectric detector and photoacoustic spectroscopy of electrodes for the monitoring of electrochromic systems, and the results showed that the detector was able to achieve state-of-the-art performance.
Abstract: Analytical Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 In situ monitoring of electrochromic systems by piezoelectric detector photoacoustic spectroscopy of electrodes Richard E. Malpas, and Allen J. Bard Anal. Chem., 1980, 52 (1), 109-112• DOI: 10.1021/ac50051a026 • Publication Date (Web): 01 May 2002 Downloaded from http://pubs.acs.org on February 13, 2009
TL;DR: The only evidence for a Q-cycle in chloroplasts remains with the redox behaviour of cytochrome b-563, and the functional role of this cy tochrome is investigated, along the lines suggested in [3].
Patent•
03 Jul 1980
TL;DR: In this article, the authors propose to prevent leakage current and achieve the reduction of power consumption by bonding an electron blocking layer which blocks the movement of electrons between a solid electrochromic material layer and dielectric layer.
Abstract: PURPOSE:To prevent leakage current and achieve the reduction of power consumption by bonding an electron blocking layer which blocks the movement of electrons between a solid electrochromic material layer and dielectric layer. CONSTITUTION:The element is constituted by providing an antireflecting film 6a composed of Al2O3 in adjacency to a glass substrate 1a, then subsequently laminating a transparent electrode 2a, on the one side, composed of In2O3, a dielectric layer 3 composed of NiO, an electron blocking layer 4 composed of Ta2O6, a solid electrochromic material layer 5 composed of WO3, a transparent electrode 2b on the other and antireflecting film 6b and providing a glass substrate 1b by way of an adhesive agent layer 7. If with this constitution the electrodes 2a, 2b of this element are connected respectively to the positive pole and negative pole of a DC power source S, the solid electrochromic material layer 5 and dielectric layer 3 cause oxidation-reduction reaction, thereby forming color. The electron blocking layer 4 blocks the leakage current moving between the electrodes, thereby preventing the increase in power consumption.
Patent•
10 Sep 1980TL;DR: An electrochromic display device and apparatus for producing such a device including a display electrode, a confronting electrode, and an electrolyte-impregnated porous layer disposed between the electrodes is described in this paper.
Abstract: An electrochromic display device and apparatus for producing such a device including a display electrode, a confronting electrode, and an electrolyte-impregnated porous layer disposed between the electrodes. The porous member has an average pore diameter of 0.1 to 50 μm with porous spaces occupying at least 30% by volume of the porous member. Pigment is held in the porous spaces to an extent of 1 to 50% by volume of the porous spaces. With this construction, the display device provides an excellent display background.
Patent•
13 Feb 1980
TL;DR: In this article, an electrochromic display cell comprises two opposing glass substrates, transparent electrodes formed on the glass substrate, and electro-chromic layers formed on transparent electrodes, and a liquid electrolyte disposed in the cell.
Abstract: An electrochromic display cell comprises two opposing glass substrates, transparent electrodes formed on the glass substrates, electrochromic layers formed on the transparent electrodes, and a liquid electrolyte disposed in the cell. The electrochromic layer is formed in the following manner. A metal compound such as tungsten chloride (WCl 6 ) is dissolved in an organic solvent such as an alcohol to obtain an organic solution including hydroxide (W(OH) 6 ). The organic solution is painted on the transparent electrode and, then calcined to obtain the electrochromic layer including tungsten oxide (WO 3 ).
TL;DR: In this article, the transmembrane potential difference induced by an external electric field was analyzed by measuring directly the electrochromic absorption changes (M) of the membrane pigments which indicate the induced membrane potential.
Patent•
18 Jun 1980
TL;DR: The all solid-state ECD of as discussed by the authors is composed of an oxidizable film capable of a redox reaction and showing a change in the transmittance in a certain wavelength range in the oxidized state, a reducible one capable of redox reactions in the reduced state, an insulating film provided between said films and allowing proton conduction but prohibiting electron conduction.
Abstract: The all solid-state ECD of the present invention features a structure composed of an oxidizable film capable of a redox reaction and showing a change in the transmittance in a certain wavelength range in the oxidized state, a reducible film capable of a redox reaction and showing a change in the transmittance in a certain wavelength range in the reduced state, an insulating film provided between said films and allowing proton conduction but prohibiting electron conduction, and a pair of electrodes between which said three films are maintained, wherein said oxidizable film is substantially composed of iridium hydroxide and/or nickel hydroxide, while said reducible film is substantially composed of tungsten oxide and/or molybdenum oxide. The ECD shows several faster response speeds, a significantly reduced voltage and the change in the transmittance improved more than six times with a drive voltage reduced to 1/8.
TL;DR: Electrochromic materials of anthaquinones can form highly colored salts reversibly in response to an applied potential and may be used in display devices that have good stability and an efficiency as high as 250 cm2/C.
Abstract: Anions of anthaquinones can form highly colored salts reversibly in response to an applied potential. These electrochromic materials may be used in display devices that have good stability and an efficiency as high as 250 cm2/C. Some cells can be color modulated at less than 0.10 V. Others have a sharp threshold for color modulation near 1.5 V and may be suitable for multiplexing.
TL;DR: In this article, the diffusion of oxygen vacancies from the oxide-electrolyte interface into the bulk of the polycrystalline layers of WO3−x·H2O (0
Abstract: Polycrystalline layers of WO3·H2O are obtained by anodization of tungsten in 1 N H2SO4 at 70° C. The cathodic reduction of these layers in acid solutions causes the formation of blue WO3−x·H2O (0