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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Lithium cobalt oxide thin films : preparation and characterization for electrochromic applications /

Wei, Guang. January 1991 (has links)
Thesis (Ph.D.)--Tufts University, 1991. / Submitted to the Dept. of Electrical Engineering (Electro-Optics Option). Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;
2

Synthesis and characterization of novel organometallic and organic electrochromic materials /

Desjardins, Pierre January 1900 (has links)
Thesis (Ph. D.)--Carleton University, 2001. / Includes bibliographical references. Also available in electronic format on the Internet.
3

Novel deposition methods for metal dithiolenes

Dalgleish, Simon January 2010 (has links)
Square planar metal bis-dithiolenes are interesting targets for incorporation into electronic and optoelectronic devices as they characteristically display multiple stable redox states, coupled with strong absorption at particularly low energies. This work focuses on novel methods for the formation of thin films of metal bis-dithiolenes for incorporation into devices. The synthesis, structure and spectroscopic properties of a novel class of polymerisable heteroleptic nickel dithiolene complex, containing pendent thiophene units, [Ni(R2pipdt)(b-3ted)] are described [R = Bz (3a), iPr (3b); pipdt = piperazine- 3,2-dithione; b-3ted = bis-(3-thienyl)-1,2-ethylenedithiolene]. Electrooxidation of (3a) showed it to incorporate into a polymeric film over an electrode surface, which consisted of intact dithiolene units, by covalent linking of the pendent thienyl groups. This polymer film showed some redox activity, with the intense, low energy, absorption red-shifted by 4360 cm-1. Co-polymerisation of (3a) with thiophene yielded a highly conductive film, with the intense, low energy, absorption red-shifted to a lesser extent (3500 cm-1). The films displayed interesting optical properties, however, their use was restricted by their poor redox activity, thought to be due to poor ion transport through the films. The synthesis of two novel dithiolene ligand systems, containing pendent polymerisable indolyl groups (mi-5edt and mi-5hdt), are described, and their incorporation into complexes investigated for nickel [Ni(mi-5edt)2 (6) and Ni(mi-5hdt)2 (8)], and copper f[Cu(mi-5edt)2][TMA] ([7][TMA]) and [Cu(mi-5hdt)2][TMA] ([9][TMA])g investigated [(mi-5edt) = 1-(N-methylindol-5-yl)-ethane-1,2-dithiolate and (mi-5hdt) = 1- (N-methylindol-5-yl)-hex-1-ene-1,2-dithiolate, TMA = tetramethylammonium]. Each complex was characterised in terms of its structure, redox and optical properties, and the effect of the ligand design, and the metal centre, compared. The complexes of nickel were shown to yield polymer films under electrooxidative conditions, through covalent linking of the indolyl groups, with superior redox activity to 3a, and with an equally intense low energy absorption. The monoanionic complexes of copper were shown to deposit, under electrooxidative conditions, as neutral molecular films that were otherwise unobtainable by conventional solution techniques. The incorporation of the more soluble novel indolyl functionalised nickel dithiolene 8 into electronic devices was investigated. Electrochromic devices were formed using poly- 8 as the active layer. The devices were able to switch their optical absorption profile at 860 nm through three absorbing states by application of a suitable potential difference across the film. Field-effect transistors were fabricated using a molecular film of 8 as the active layer. The devices showed ambipolar charge transport properties, though with a bias for n-channel operation, with mobilities μ ≈ 1 x 10-4 cm2V-1s-1. Photovoltaic devices were formed from a blended film of 8 with P-3HT and with MDMO-PPV [P-3HT = regioregular poly-3-hexylthiophene, MDMO-PPV = poly(2-methoxy-5- (3',7'-dimethyloctyloxy)-1,4-phenylene-vynylene)]. 8 was shown to contribute to the photocurrent at wavelengths beyond the polymer component, thus harvesting more visible light, however efficiencies below 0.1 % suggested inefficient charge transport by 8 in the film. Structurally continuous films of Ni(b-3ted)2 (10) could be formed by a process of electrodeposition. The formed films displayed conductivities 40 times greater than for conventional solution cast films. By a detailed study of the level of residual ion doping, the molecular packing, and the morphology of the films, this improved performance was attributed to the formation of a more dense polycrystalline array, with larger crystallites, which formed good electronic contact with the electrodes, and with each other. This electrodeposition technique was used to fabricate field-effect transistors from 10. The devices showed poor mobilities (μ ≈ 1 x 10 -8 cm2V-1s-1), owing to the poor intermolecular overlap of the dithiolene units in the solid-state, but suggested this technique to be suitable for a wide range of semiconductors, with more favourable electronic properties, as an alternative to conventional vapour or solution deposition.
4

Desenvolvimento de janelas eletrocrômicas / Development of eletrochromic windows

Sentanin, Franciani Cassia 09 January 2013 (has links)
Este trabalho apresenta os resultados do preparo e caracterização de janelas eletrocrômicas (ECD) contendo filmes finos de WO3 como camada eletrocrômica, CeO2-TiO2 como contra-eletrodo e eletrólitos a base de polímeros naturais plastificados. Os filmes finos de CeO2-TiO2 e WO3 foram preparados pelo processo sol-gel e usados para montagem de dispositivos (janelas) eletrocrômicas com variados eletrólitos poliméricos. Os filmes finos e as janelas foram caracterizados através de medidas de densidade de carga, voltametria cíclica e transmitância. Os filmes de CeO2-TiO2 e WO3 apresentaram respectivamente, valores de densidade de carga de 11,8 e 27,8 mC/cm2, e razão de carga anódica/catódica de 0,98 e 0,85. As análises voltamétricas dos filmes finos revelaram picos característicos dos processos de oxidação e redução e as análises espectroscópicas a transmitância de 80 e 78 %, respectivamente. Foram preparadas e caracterizadas janelas com eletrólitos a base de gelatina com ácido acético; gelatina com LiI/I2; gelatina com agar; gelatina com líquidos iônicos; gelatina com líquidos iônicos e triflato de európio; poli(vinil butirato) (PVB) com LiI/I2; PVB com LiClO4; agar com LiClO4; agar com líquidos iônicos; DNA; DNA com LiClO4; DNA-cloreto de hexadeciltrimetilamônio (DNA-CTMA) com azul da Prússia; DNA com PEDOT:PSS (poli(3,4-etilenodioxitiofeno):poli(sulfonato de estireno)); DNA-CTMA com PEDOT:PSS. Os melhores resultados de densidade de carga de 5,4 e 6,0 mC/cm2 foram obtidas para os dispositivos com eletrólitos de gelatina com agar e agar com LiClO4. A razão de carga anódica/catódica desses dispositivos foi de 0,98 e 0,99. Os voltamogramas cíclicos das amostras estudadas revelaram picos anódicos e catódicos referentes à extração e inserção de íons lítio e elétrons no filme de WO3. As análises de transmitância em 550 nm entre o estado colorido e descolorido das janelas mostrou os valores de 28% para a janela contendo eletrólito a base de PVB com LiI/I2. Além disso, também foi verificada a estabilidade dos dispositivos revelando a duração entre 100 a 400 ciclos cronoamperometricos, dependendo do eletrólito usado. Os resultados obtidos mostram que as janelas estudadas são potenciais candidatas às aplicações práticas. / This work presents the results of the preparation and characterization of electrochromic windows (ECD) containing thin films of WO3 as electrochromic layer, CeO2-TiO2 as the counter electrode and natural polymer-based electrolytes. Thin films of CeO2-TiO2 and WO3 were prepared by the sol-gel process and used to assembly the electrochromic devices (windows) with different polymer electrolytes. The thin films and windows samples were characterized by charge density, cyclic voltammetry and transmittance measurements. CeO2-TiO2 and WO3 thin films revealed charge density values of 11.8 and 27.8 mC/cm2, and anodic/cathodic charge relation of 0.98 and 0.85, respectively. The cyclic voltammograms revealed the peaks characteristic of the processes of oxidation and reduction and the spectroscopic analysis the transmittance of 80 and 78%, respectively. Electrochromic windows were assembled with electrolytes based on gelatin with acetic acid; gelatina with LiI/I2, gelatin with agar, gelatin with ionic liquids, gelatin with ionic liquids and europium triflate, PVB (poly (vinyl butyrate)) with LiI/I2; PVB with LiClO4; agar with LiClO4, agar with ionic liquids; DNA, DNA with LiClO4; DNA-CTMA (hexadecyltrimethylammonium chloride) with Prussian Blue; DNA with PEDOT:PSS (poly (3,4-ethylenedioxythiophene) poly(styrene sulfonate) ) and DNA-CTMA with PEDOT: PSS. The best results of charge density of 5.4 and 6.0 mC/cm2 and anodic/cathodic charge relations of 0.98 and 0.99 were obtained for the samples containing electrolytes based on gelatin with agar and agar with LiClO4, respectively. The cyclic voltammograms of the electrochromic windows showed cathodic and anodic peaks related to the insertion and extraction of lithium ions and electrons in the film of WO3. The transmittance measurements at 550 nm revealed 28% between the colored and discolored state of the windows with PVB-LiI/I2 electrolyte. Moreover, the stability measurements showed that the ECD remain their transmittance difference during of 100 to 400 of chronoaperometric cycling, depending on the electrolyte used. The obtained results indicate the possibility of use the naturalmacromolecules-based electrolytes in practical electrochromic windows.
5

Desenvolvimento de membranas à base de DNA para aplicação em dispositivos eletrocrômicos / DNA based electrochromic devices

Nascimento, Alessandra Firmino 30 June 2014 (has links)
Os polímeros naturais e macromoléculas, como polissacarídeos, gelatina e DNA têm atraído recentemente a atenção significativa da comunidade científica por suas propriedades estruturais e elétricas. O ácido desoxiribonucleico (DNA) possui propriedades eletrolíticas que aumentam quando dissolvido em água, isso ocorre devido à presença de átomos facilmente ionizáveis, tais como prótons e/ou íons sódio. Membranas ionicamente condutoras à base de DNA plastificadas com glicerol/ polietileno glicol (PEG) e contendo polímeros condutores, tais como, PEDOT:PSS (poli (3,4- etilenodioxitiofeno)): poli(estireno sulfonato), POEA (poli (o - etoxianilina)) ou o corante electrocrômico Azul da Prússia (AzP) foram preparadas, caracterizadas e aplicadas em dispositivos electrocrômicos. Os resultados demonstraram que o DNA pode ser plastificado com glicerol, resultando numa membrana transparente com boa condutividade iônica. A caracterização das amostras foi realizada através de medidas de condutividade iônica em função da temperatura, análise termogravimétrica - TGA, análise estrutural por difração de raios-X, microscopia eletrônica - MEV e análise espectroscópica no UV - Vis. Os valores de condutividade iônica à temperatura ambiente foram em gama de 10-4 a 10-5S/cm e aumentam linearmente com o aumento da temperatura, seguindo a relação de Arrhenius. Os valores de condutividade iônica para as membranas dopadas variaram, dependendo do polímero ou corante adicionado, da ordem de 10-5S/cm para as amostras à base de DNA puro a 10-4S/cm para as amostras contendo POEA, PEDOT ou AzP, em temperatura ambiente. Observou-se que as amostras apresentam boa estabilidade térmica, até 170°C, com transparência variável, dependendo da espécie adicionada. Os resultados de raios-X evidenciaram uma estrutura semicristalina das membranas obtidas. Finalmente, as membranas foram aplicadas em pequenos dispositivos electrocrômicos (ECD) e mostraram uma mudança de transmissão de até 10 % de colorido para estados descoloridos. Os dispositivos montados foram caracterizados através de medidas de voltametria e cronocoulometria para os potenciais de (-2,0 e +1,8; e -3,5 e +3,0)V. Os resultados da preparação e caracterização de janelas eletrocrômicas revelaram melhor valor de densidade de carga de 2,8 mC/cm2 para a janela contendo eletrólito a base de DNA-PEDOT. Todos os resultados obtidos mostraram que as membranas à base de DNA são condutoras ionicamente, têm boa transparência e adesão a propriedades do aço e vidro e são materiais promissores para serem aplicadas em dispositivos eletrocrômicos. / Natural polymers and macromolecules such as polysaccharides, gelatin, and DNA have recently attracted significant attention from the scientific community for their interesting structural and electrical properties. Deoxyribonucleic acid (DNA) has electrolytic properties that are enhanced when dissolved in water due to the presence easily ionizable atoms such as proton and/or sodium. Ionically conductive membranes based on DNA plasticized with glycerol and DNA containing conducting polymers, such as, either PEDOT (poly(3,4-ethylenedioxythiophene)), POEA (poly (o-ethoxyaniline)) or electrochromic dye Prussian Blue (PB) were prepared, characterized and applied in electrochromic devices. It has been shown that DNA can be plasticized with glycerol, resulting in a transparent membrane with good ionic conductivity. The characterization of the samples was performed by ionic conductivity measurements as a function of temperature, TGA thermal analysis, and structural analysis by X-ray diffraction, microscopic by SEM and UV-Vis spectroscopic analysis. The ionic conductivity values at room temperature were in range of 10-4 to 10-5S/cm and increases linearly with increasing temperature, following the Arrhenius relationship. The ionic conductivity values for the studied doped membranes varied, depending on the added polymer or dye, from order 10-5S/cm for the pure DNA-based samples to 10-4S/cm for the samples containing PEDOT or PB, at room temperature. It was observed that the samples exhibit a good thermal stability up to 170ºC, with variable transparency, depending on the added molecule. The X-ray results evidenced a semicrystalline structure of the obtained membranes. Finally, the membranes were applied in small electrochromic devices (ECDs) and have shown an up to 10% transmission change from colored to bleached states. The inserted/extracted charges were of 2,8 mC/cm2 after applying potential of -2.0/+1.8V and -3.5/+3.0V on ECD with DNA-PEDOT electrolyte. All obtained results showed that DNA-based ionically conducting membranes have good transparency and adhesion to glass and steel properties and are very promising materials to be applied in electrochromic devices.
6

Preparation and characterization of lithium cobalt oxide by chemical vapor deposition for application in thin film battery and electrochromic devices /

Kenny, Leo Thomas. January 1996 (has links)
Thesis (Ph.D.)--Tufts University, 1996. / Adviser: Terry E. Haas. Submitted to the Dept. of Chemistry. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;
7

A study of the thin film battery electrolyte lithium phosphorus oxynitride deposited by an ion beam assisted process /

Vereda-Moratilla, Fernando. January 1900 (has links)
Thesis (Ph.D.)--Tufts University, 2003. / Adviser: Ronald B. Goldner. Submitted to the Dept. of Electrical and Computer Engineering. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;
8

Photofunctional molecular materials for chemical sensing, bioimaging and electrochromic applications

Ma, Yun 24 August 2015 (has links)
This thesis is dedicated to developing novel photofunctional molecular materials for the applications in chemical sensing, bioimaging and electrochromic. To begin with, a brief introduction of photofunctional molecular materials and an overview of their applications in chemical sensing, bioimaging and electrochromic were presented in Chapter 1. In chapter 2, we have synthesized a series of water-soluble phosphorescent cationic iridium(III) solvato complexes (1-7) as multicolor cellular probes for imaging in living cells. All of these complexes can be dissolved in PBS. The emission of complexes can be tuned from green to red by changing the chemical structure of cyclomedtalating ligands. All complexes exhibit low cytotoxicity to living cells and exhibit cell membrane permeability and specific staining of cytoplasm. They enter the cells by the mechanism of energy-independent passive diffusion mechanisms. More importantly, complex 7 can act as a two-photon phosphorescent cellular probe, and fluorescence lifetime imaging microscopy is successfully applied for bioimaging in the presence of short-lived background fluorescence. We developed two excellent optical probes for CO2 detection in Chapter 3. The first one for the CO2 detection is a phosphorescent probe based on an iridium(III) complex with 2-phenylimidazo-[4,5-f][1,10]phenanthroline. After bubbling CO2 into the detection solution, the quenched phosphorescence by the addition of CH3COO can be recovered. Photobleaching experiment demonstrates that this phosphorescent CO2 probe shows higher photostability than some of the reported organic probes. More importantly, the time-resolved PL experiment demonstrates that this probe can be used to detect CO2 in the presence of strong background fluorescence, which improves the sensitivity and signal-to-noise ratio of the sensor in complicated media. The second one is a water-soluble fluorescent probe based on tetraphenylethene derivative. After bubbling CO2 into the detection solution, remarkable color change and fluorescence enhancement could be observed. The response of this probe to CO2 in aqueous solution is fast and the detection limit is about 2.4 × 106 M. To emphasize the practical application of this probe, a porous film was successfully fabricated by mixing the dye with sodium carboxymethyl cellulose in water, which can serve as an efficient CO2 gas sensor. More importantly, this probe exhibits low cytotoxicity towards live cells and has the ability to monitor the external CO2 concentration changes of living cells. Chapter 4 focused on the development of novel soft salt based phosphorescent probe. This type of probe consists of two oppositely charged ionic complexes with two distinguishable emission colors, which makes it a perfect candidate as a ratiometric probe. The emission color of 10 changes from blue to red with increasing pH value. 10 is cell-permeable and exhibits low cytotoxicity, and it has been successfully applied for ratiometric pH imaging with the use of confocal microscopy, demonstrating its great potential for intracellular environment monitoring. Furthermore, phosphorescence lifetime imaging experiments can detect intracellular pH variations by photoluminescence lifetime measurements, which allowed for eliminating background fluorescence and selecting long-lived phosphorescence images. Quantitative measurement of intracellular pH fluctuations caused by oxidative stress has been successfully carried out for 10 based on the pH-dependent calibration curve. A series of cationic Zn(II) complexes has been designed and synthesized in chapter 5. The photophysical properties of these Zn(II) complexes are affected by the counterions. By altering the counterions, the emission peak can be changed from 549 nm to 622 nm. Interestingly, the CIE coordinate and the emission colors can be simply tuned by adjusting the concentration of 11d in the polyether. Under an electric field of about 15 V applied onto the electrodes, the emission color of the solution of 11b-11d near the cathode changed its original emission color to sky blue. Based on this interesting electrochromic fluorescence of 11d, a quasi-solid information recording device has been successfully designed. Furthermore, data encryption has been realized by combining 1d with BODIPY, and information decoding processed has been accomplished, for the first time, by employing TPA excitation techniques, in which the large TPA cross section of 11d is differentiated from small TPA cross section of common organic dyes. Finally, Chapters 6 and 7 present the concluding remarksand the experimental details of the work described in Chapters 25
9

Desenvolvimento de membranas à base de DNA para aplicação em dispositivos eletrocrômicos / DNA based electrochromic devices

Alessandra Firmino Nascimento 30 June 2014 (has links)
Os polímeros naturais e macromoléculas, como polissacarídeos, gelatina e DNA têm atraído recentemente a atenção significativa da comunidade científica por suas propriedades estruturais e elétricas. O ácido desoxiribonucleico (DNA) possui propriedades eletrolíticas que aumentam quando dissolvido em água, isso ocorre devido à presença de átomos facilmente ionizáveis, tais como prótons e/ou íons sódio. Membranas ionicamente condutoras à base de DNA plastificadas com glicerol/ polietileno glicol (PEG) e contendo polímeros condutores, tais como, PEDOT:PSS (poli (3,4- etilenodioxitiofeno)): poli(estireno sulfonato), POEA (poli (o - etoxianilina)) ou o corante electrocrômico Azul da Prússia (AzP) foram preparadas, caracterizadas e aplicadas em dispositivos electrocrômicos. Os resultados demonstraram que o DNA pode ser plastificado com glicerol, resultando numa membrana transparente com boa condutividade iônica. A caracterização das amostras foi realizada através de medidas de condutividade iônica em função da temperatura, análise termogravimétrica - TGA, análise estrutural por difração de raios-X, microscopia eletrônica - MEV e análise espectroscópica no UV - Vis. Os valores de condutividade iônica à temperatura ambiente foram em gama de 10-4 a 10-5S/cm e aumentam linearmente com o aumento da temperatura, seguindo a relação de Arrhenius. Os valores de condutividade iônica para as membranas dopadas variaram, dependendo do polímero ou corante adicionado, da ordem de 10-5S/cm para as amostras à base de DNA puro a 10-4S/cm para as amostras contendo POEA, PEDOT ou AzP, em temperatura ambiente. Observou-se que as amostras apresentam boa estabilidade térmica, até 170°C, com transparência variável, dependendo da espécie adicionada. Os resultados de raios-X evidenciaram uma estrutura semicristalina das membranas obtidas. Finalmente, as membranas foram aplicadas em pequenos dispositivos electrocrômicos (ECD) e mostraram uma mudança de transmissão de até 10 % de colorido para estados descoloridos. Os dispositivos montados foram caracterizados através de medidas de voltametria e cronocoulometria para os potenciais de (-2,0 e +1,8; e -3,5 e +3,0)V. Os resultados da preparação e caracterização de janelas eletrocrômicas revelaram melhor valor de densidade de carga de 2,8 mC/cm2 para a janela contendo eletrólito a base de DNA-PEDOT. Todos os resultados obtidos mostraram que as membranas à base de DNA são condutoras ionicamente, têm boa transparência e adesão a propriedades do aço e vidro e são materiais promissores para serem aplicadas em dispositivos eletrocrômicos. / Natural polymers and macromolecules such as polysaccharides, gelatin, and DNA have recently attracted significant attention from the scientific community for their interesting structural and electrical properties. Deoxyribonucleic acid (DNA) has electrolytic properties that are enhanced when dissolved in water due to the presence easily ionizable atoms such as proton and/or sodium. Ionically conductive membranes based on DNA plasticized with glycerol and DNA containing conducting polymers, such as, either PEDOT (poly(3,4-ethylenedioxythiophene)), POEA (poly (o-ethoxyaniline)) or electrochromic dye Prussian Blue (PB) were prepared, characterized and applied in electrochromic devices. It has been shown that DNA can be plasticized with glycerol, resulting in a transparent membrane with good ionic conductivity. The characterization of the samples was performed by ionic conductivity measurements as a function of temperature, TGA thermal analysis, and structural analysis by X-ray diffraction, microscopic by SEM and UV-Vis spectroscopic analysis. The ionic conductivity values at room temperature were in range of 10-4 to 10-5S/cm and increases linearly with increasing temperature, following the Arrhenius relationship. The ionic conductivity values for the studied doped membranes varied, depending on the added polymer or dye, from order 10-5S/cm for the pure DNA-based samples to 10-4S/cm for the samples containing PEDOT or PB, at room temperature. It was observed that the samples exhibit a good thermal stability up to 170ºC, with variable transparency, depending on the added molecule. The X-ray results evidenced a semicrystalline structure of the obtained membranes. Finally, the membranes were applied in small electrochromic devices (ECDs) and have shown an up to 10% transmission change from colored to bleached states. The inserted/extracted charges were of 2,8 mC/cm2 after applying potential of -2.0/+1.8V and -3.5/+3.0V on ECD with DNA-PEDOT electrolyte. All obtained results showed that DNA-based ionically conducting membranes have good transparency and adhesion to glass and steel properties and are very promising materials to be applied in electrochromic devices.
10

Desenvolvimento de janelas eletrocrômicas / Development of eletrochromic windows

Franciani Cassia Sentanin 09 January 2013 (has links)
Este trabalho apresenta os resultados do preparo e caracterização de janelas eletrocrômicas (ECD) contendo filmes finos de WO3 como camada eletrocrômica, CeO2-TiO2 como contra-eletrodo e eletrólitos a base de polímeros naturais plastificados. Os filmes finos de CeO2-TiO2 e WO3 foram preparados pelo processo sol-gel e usados para montagem de dispositivos (janelas) eletrocrômicas com variados eletrólitos poliméricos. Os filmes finos e as janelas foram caracterizados através de medidas de densidade de carga, voltametria cíclica e transmitância. Os filmes de CeO2-TiO2 e WO3 apresentaram respectivamente, valores de densidade de carga de 11,8 e 27,8 mC/cm2, e razão de carga anódica/catódica de 0,98 e 0,85. As análises voltamétricas dos filmes finos revelaram picos característicos dos processos de oxidação e redução e as análises espectroscópicas a transmitância de 80 e 78 %, respectivamente. Foram preparadas e caracterizadas janelas com eletrólitos a base de gelatina com ácido acético; gelatina com LiI/I2; gelatina com agar; gelatina com líquidos iônicos; gelatina com líquidos iônicos e triflato de európio; poli(vinil butirato) (PVB) com LiI/I2; PVB com LiClO4; agar com LiClO4; agar com líquidos iônicos; DNA; DNA com LiClO4; DNA-cloreto de hexadeciltrimetilamônio (DNA-CTMA) com azul da Prússia; DNA com PEDOT:PSS (poli(3,4-etilenodioxitiofeno):poli(sulfonato de estireno)); DNA-CTMA com PEDOT:PSS. Os melhores resultados de densidade de carga de 5,4 e 6,0 mC/cm2 foram obtidas para os dispositivos com eletrólitos de gelatina com agar e agar com LiClO4. A razão de carga anódica/catódica desses dispositivos foi de 0,98 e 0,99. Os voltamogramas cíclicos das amostras estudadas revelaram picos anódicos e catódicos referentes à extração e inserção de íons lítio e elétrons no filme de WO3. As análises de transmitância em 550 nm entre o estado colorido e descolorido das janelas mostrou os valores de 28% para a janela contendo eletrólito a base de PVB com LiI/I2. Além disso, também foi verificada a estabilidade dos dispositivos revelando a duração entre 100 a 400 ciclos cronoamperometricos, dependendo do eletrólito usado. Os resultados obtidos mostram que as janelas estudadas são potenciais candidatas às aplicações práticas. / This work presents the results of the preparation and characterization of electrochromic windows (ECD) containing thin films of WO3 as electrochromic layer, CeO2-TiO2 as the counter electrode and natural polymer-based electrolytes. Thin films of CeO2-TiO2 and WO3 were prepared by the sol-gel process and used to assembly the electrochromic devices (windows) with different polymer electrolytes. The thin films and windows samples were characterized by charge density, cyclic voltammetry and transmittance measurements. CeO2-TiO2 and WO3 thin films revealed charge density values of 11.8 and 27.8 mC/cm2, and anodic/cathodic charge relation of 0.98 and 0.85, respectively. The cyclic voltammograms revealed the peaks characteristic of the processes of oxidation and reduction and the spectroscopic analysis the transmittance of 80 and 78%, respectively. Electrochromic windows were assembled with electrolytes based on gelatin with acetic acid; gelatina with LiI/I2, gelatin with agar, gelatin with ionic liquids, gelatin with ionic liquids and europium triflate, PVB (poly (vinyl butyrate)) with LiI/I2; PVB with LiClO4; agar with LiClO4, agar with ionic liquids; DNA, DNA with LiClO4; DNA-CTMA (hexadecyltrimethylammonium chloride) with Prussian Blue; DNA with PEDOT:PSS (poly (3,4-ethylenedioxythiophene) poly(styrene sulfonate) ) and DNA-CTMA with PEDOT: PSS. The best results of charge density of 5.4 and 6.0 mC/cm2 and anodic/cathodic charge relations of 0.98 and 0.99 were obtained for the samples containing electrolytes based on gelatin with agar and agar with LiClO4, respectively. The cyclic voltammograms of the electrochromic windows showed cathodic and anodic peaks related to the insertion and extraction of lithium ions and electrons in the film of WO3. The transmittance measurements at 550 nm revealed 28% between the colored and discolored state of the windows with PVB-LiI/I2 electrolyte. Moreover, the stability measurements showed that the ECD remain their transmittance difference during of 100 to 400 of chronoaperometric cycling, depending on the electrolyte used. The obtained results indicate the possibility of use the naturalmacromolecules-based electrolytes in practical electrochromic windows.

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