Search results for "Electrochromic Device"
showing 10 items of 18 documents
<title>Functional models of electrochromic devices: cycling capacity and degradation</title>
1997
Electrical transfer and diffusion of ions and the irreversibility of ion and electron processes in heterojunctions are responsible for degradation of ionic devices. These processes for electrochromic devices (ECD) determine the cycling capacity and lifetime. The basic problem here is how to match the electrochemical parameters (including chemical potential) of heterojunction. The experiments had been carried out on ECD based on system: (phi) - -(phi) , where AAH is solid electrolyte based on antimony acid hydrates. The cycling capacity and degradation processes of ECD are investigated by electro-optical and electro-chemical spectroscopy. The analysis of experimental data are based on assump…
Synthesis, characterization, and hierarchical organization of tungsten oxide nanorods: spreading driven by Marangoni flow.
2009
Tungsten oxide nanorods were synthesized by a soft chemistry approach using tungsten alkoxide and trioctyl amine and oleic acid as the surfactants. The optical properties of the nanorods were studied. The nanorods were found to be soluble in a wide range of solvents like chloroform, cyclohexane, and so on. Upon solvent evaporation, the nanorods formed hierarchically organized solid state structures. Depending on the solvent used, the nanorods organized in different mesostructures. Moreover, the organization of the nanorods from mixtures of polar and nonpolar solvents was studied. Here, the Marangoni effect resulting from differences in the surface tensions of the two solvents was found to p…
Proton conducting polymer composites for electrochromic devices
1999
Abstract This report describes composite proton electrolytes composed of nanosize zirconium phosphate or antimonic acid particles suspended in a poly(vinyl acetate)/glycerin gel matrix. The proton conductivity was 10 −3 –10 −4 S/cm at room temperature, thermal stability prevailed up to at least 110°C, and compatibility was found with oxide electrodes; these properties makes the electrolyte suitable for use in solid state electrochemical devices. The temperature dependence of the conductivity was found to obey the Williams-Landel-Ferry relationship at temperatures over 60°C, thus suggesting that the ion conductivity in the composite electrolyte can be described by mechanisms normally taken t…
Polymer-based symmetric electrochromic devices
1999
Abstract The fact that conjugated polymers repeatedly undergo electrochemical doping/undoping processes, which are accompained by color changes, makes these materials very attractive, and much effort has been devoted to their use in advanced devices. There is renewed interest in electroactive polymers that reversibly undergo both p- and n-doping because of their potential application in symmetric electrochemical devices. We employed fused molecules, dithienothiophenes, as monomers to obtain polymers with a narrow band gap suitable for n- and p-doping. The performance results of two symmetric electrochromic devices having as electrodes both poly(dithieno[3,4-b:3',4'-d]thiophene) (pDTT1) and …
<title>Proton conducting polymer electrolytes for electrochromic devices</title>
1997
This report concerns a composite proton electrolyte suitable for use in electrochromic devices. The electrolyte consists of nanosize hydrated oxide (aluminum, silicon or antimonic) particles suspended in a poly(vinyl acetate) matrix. All of the water was strongly bonded, thus making the electrolytes less harmful without considerably decreasing the conductivity. The proton conductivity of the electrolyte was approximately 10-4 S/cm at room temperature, practically independent of its amount of absorbed water.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
ELECTROCHROMIC PERFORMANCE OF A NOVEL POLY(NAPHTHALENEDIIMIDEQUATERTHIOPHENE)
2013
Conjugated polymers (CP) display several interesting properties which enable them their application in different fields such as solar cells, light emitting diodes, field effect transistors, electrochromic devices to cite a few. One of the most interesting properties of this class of materials is their ability of switching from a conductive to an insulating state and vice versa by changing their redox state. The possibility to switch from an oxidized to a neutral or reduced state induces variations of the optical spectrum due to changes in the electron excitation energy configuration resulting in electrochromism. Nowadays, electrochromic conjugated polymers are stimulating the development of…
Aluminium oxide — Poly(vinyl acetate) composite electrolyte for electrochromic devices
1997
This report describes composite proton electrolytes composed of nanosize activated aluminium oxide particles with different surface acidity suspended in a poly(vinyl acetate)/glycerine matrix. The conductivity of the composite was found to increase by going from basic to neutral to acidic aluminium oxide. Tests in laminated electrochromic devices with tungsten oxide and nickel hydroxide films showed that the acidic electrolyte is compatible with WO3, the basic electrolyte is compatible with Ni(OH)2, and the neutral electrolyte is compatible with both of the electrodes.
Proton-conducting zirconium phosphate/poly(vinyl acetate)/glycerine gel electrolytes
2003
This work reports on a proton gel electrolyte composed of zirconium phosphate (ZP) particles suspended in a poly(vinyl acetate)/glycerine matrix. The material was studied by X-ray powder diffraction, differential scanning calorimetry, impedance spectroscopy, and spectrophotometry. It had a proton conductivity of 1–0.1 mS/cm at room temperature and remained stable and transparent up to at least 110 °C; it therefore appears suitable for uses in electrochromic devices. The structure of the ZP powder and of the gel is discussed in terms of water removal from interplanar spaces by heating or exfoliation. It is suggested that an exfoliation of the layered structure of ZP by intercalation of glyce…
Use of RGB digital video analysis to study electrochemical processes involving color changes
2017
Color changes on an electrode surface during the course of electrochemical processes were monitored by in situ digital video recording. The evolution of standard red, green and blue (sRGB) intensity channels extracted from digital images showed a close relationship with the electrochemical processes taking place. In particular, the derivative of the sRGB mean intensity with respect to time (dI−/dt) gave useful insights into the electrochemical mechanism. The standard deviation (std) of the sRGB intensity provided information about the color homogeneity of the studied region on the electrode surface. We selected poly(o-toluidine) electrochromism on a transparent electrode and anodic copper d…
Electrochromic Devices Incorporating Cr Oxide And Ni Oxide Films:
2000
Abstract Transparent films of Cr oxide and Ni oxide were made by reactive DC magnetron sputtering in Ar+O2+H2. They displayed anodic electrochromism with charge capacities similar to that of W oxide. Cr oxide was stable in acidic environments, while Ni oxide was stable in basic environments. Electrochromic devices were made with pristine Cr oxide or Ni oxide films operating in conjunction with W oxide and a proton conducting electrolyte. Of the two oxides, Cr oxide film allowed device operation at a lower voltage span, while the device with Ni oxide film yielded a higher transmittance in the bleached state, a larger absorptance modulation, and a more neutral color.