The Experts below are selected from a list of 60 Experts worldwide ranked by ideXlab platform

Zarbin,aldo J. G. - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis and characterization of organic-inorganic hybrids formed between conducting polymers and crystalline Antimonic Acid
    Sociedade Brasileira de Química, 2001
    Co-Authors: Beleze,fábio A., Zarbin,aldo J. G.
    Abstract:

    In this paper we report the synthesis and characterization of novel organic-inorganic hybrid materials between the crystalline Antimonic Acid (CAA) and two conductive polymers: polypyrrole and polyaniline. The hybrids were obtained by in situ oxidative polymerization of monomers by the Sb(V) present in the pyrochlore-like CAA structure. The materials were characterized by infrared and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, CHN elemental analysis and electronic paramagnetic resonance spectroscopy. The results showed that both polymers were formed in their oxidized form, with the CAA structure acting as a counter anion

  • Synthesis and characterization of organic-inorganic hybrids formed between conducting polymers and crystalline Antimonic Acid
    Sociedade Brasileira de Química, 2001
    Co-Authors: Beleze,fábio A., Zarbin,aldo J. G.
    Abstract:

    In this paper we report the synthesis and characterization of novel organic-inorganic hybrid materials between the crystalline Antimonic Acid (CAA) and two conductive polymers: polypyrrole and polyaniline. The hybrids were obtained by in situ oxidative polymerization of monomers by the Sb(V) present in the pyrochlore-like CAA structure. The materials were characterized by infrared and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, CHN elemental analysis and electronic paramagnetic resonance spectroscopy. The results showed that both polymers were formed in their oxidized form, with the CAA structure acting as a counter anion.Neste trabalho são relatadas e discutidas a síntese e a caracterização de dois materiais híbridos orgânico-inorgânico, formados entre o ácido antimônico cristalino (AAC), como fração inorgânica, e dois polímeros condutores (polipirrol e polianilina) como fração orgânica. Os híbridos foram obtidos a partir da polimerização oxidativa in situ dos monômeros, utilizando-se o próprio AAC como agente oxidante, a partir da redução dos átomos de Sb(V) presentes em sua estrutura. Os materiais foram caracterizados por espectroscopias infravermelho e Raman, voltametria cíclica, difratometria de raios-X, análise elementar CHN e espectroscopia de ressonância paramagnética eletrônica. Os resultados evidenciaram que ambos os polímeros foram formados em sua forma oxidada, com a própria estrutura do AAC atuando como contra-íon

Aldo Jose Gorgatti Zarbin - One of the best experts on this subject based on the ideXlab platform.

  • Quimica do estado solido : sintese, caracterização e decomposição termica do Acido Antimonico cristalino e derivados
    2017
    Co-Authors: Aldo Jose Gorgatti Zarbin
    Abstract:

    Resumo: Neste trabalho o Ácido Antimônico Cristalino (AAC), caracterizado como H2Sb2O6.1,5H2O, foi sintetisado pela oxidação do Sb2O3 por uma solução de H2O2. Este composto comporta-se como trocador iônico e, através de dados obtidos por difração de raios-X, observou-se que ele possui a estrutura do tipo do mineral pirocloro. Tal estrutura é característica de compostos com estequiometria A2B2O6O', onde A e B são metais. Através de espectrometria infravermelho, concluiu-se que a espécie trocável do AAC apresenta-se na forma de H3O, e ocupa a posição estrutural do átomo A. Foram realizadas reações de troca tônica do AAC com íons Ag, Cd, Pb e Fe, sendo os compostos obtidos foram caracterizados por análise química, difratometria de raios-X (DRX) , espectroscopia infravermelho (EIV), análise termogravimétrica (ATG), calorimetria diferencial de varredura (CDV) e microscopia eletrônica de varredura (MEV). Os resultados obtidos a partir de todas estas técnicas indicaram que a troca iônica ocorre com diferentes seletividades para estes íons, de tal maneira que Ag e Pb ocorrem com troca total, e Cd e Fe apresentam troca parcial. A estrutura tipo pirocloro não é destruida com a troca iônica, e comparações realizadas entre os difratogramas de raios-X de compostos obtidos por troca iônica com diferentes proporções de íons Ag e os calculados, pelo programa Lazy-Pulverix, indicaram que a troca iônica no AAC ocorre topoquimicamente, no sítio A da estrutura pirocloro. Os compostos trocados com Ag, Cd, Pb e Fe foram caracterizados, respectivamente, como: Ag2Sb2O6.1,0H2O (AAC/Ag), H0,73Cd0,635Sb2O6.1,5H2O (AAC/Cd), PbSb2O6.1,0H2O (AAC/Pb) e H1,34Fe0,22Sb2O6.1,5H2O (AAC/Fe). A ausência de troca total no AAC/Cd e AAC/Fe permitiu que os sítios não ocupados pelo íon metálico fossem submetidos à nova reação de troca (co-troca iônica), com íons Ag, formando compostos mistos originais de cádmio e prata e de ferro e prata. A estequiometria dos produtos formados foi determinada como sendo Ag0,73Cd0,635Sb2O6.1,5H2O (AAC/Cd/Ag) e Ag1,34Fe0,22Sb2O6.1,5H2O (AAC/Fe/Ag). Os dados obtidos permitiram-nos considerar uma correlação entre a extensão da troca iônica e as características estruturais dos compostos. Foram realizadas, ainda, reações de inclusão de NH3, CH3NH2 e CH3CH2NH2 no AAC. Através das técnicas já citadas, observou-se que estas aminas, quando colocadas em contacto com o AAC, no estado gasoso, são protonadas pelos sítios ácidos do AAC, ficando ligadas quimicamente à sua estrutura. O AAC, bem como todos os seus derivados obtidos por troca iônica e reações de inclusão, foram tratados à várias temperaturas, e as fases formadas foram caracterizadas. Os resultados obtidos indicaram que materiais com características interessantes e variadas, como pós cerâmicos semicondutores, condutores iônicos e catalisadores, são obtidos pelo aquecimento dos derivados do AAC. Quando comparado com os métodos tradicionais de obtenção destes materiais, tais preparações apresentaram várias vantagens. Além disso, detectou-se a formação de compostos com aplicação potencial, pelo aquecimento dos derivados mistos AAC/Cd/Ag e AAC/Fe/Ag. As fases formadas pela decomposição térmica dos derivados do AAC revelou uma nova rota de síntese para materiais, além de permitir uma boa compreensão dos fatores estruturais envolvidos no processo de troca iônica do AAC com os cátions estudados.Abstract: In this work, Cristalline Antimonic Acid (CAA), characterized as H2Sb2O6.1,5H2O, was sinthesized through the oxidation of Sb2O3 by a solution of H2O2. This substance behaves has an ionic exchanger, and it has been determined by X-ray diffraction that it has a structure similar to that of the mineral pyrochlore, A2B2O6O', where A and B are metaIs. From infrared spectroscopy, it was shown that the exchangeable species in CAA is H3O, occuping the A structural position. Ion exchange reactions of CAA were performed with the ions Ag, Cd, Pb and Fe, and the resulting products were characterized using the following techiniques: chemical analysis, X-ray diffraction (XRD), infrared spectroscopy (IS), thermogravimetric analysis (TGA) , differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). All the results indicate that ion exchange occurs with different selectivities depending on the exchanged cation. Ag and Pb represents total exchanges, while for Cd and Fe, partial exchanges where observed. The pyrochlore structure is not affected by the exchange, and the comparison between experimental X-ray diffratograms of the Ag exchanged products with different Ag quantities and calculated obtained using the Lazy-Pulverix program indicates that the exchange occurs topochemically at the A sities or the pyrochlore structure. The Ag, Cd, Pb and Fe exchanged compounds where characterized respectively as: Ag2Sb2O6.1,0H2O (CAA/Ag), H0,73Cd0,635Sb2O6.1,5H2O (CAA/Cd), PbSb2O6.1,0H2O (CAA/Pb) and H1,34Fe0,22Sb2O6.1,5H2O (CAA/Fe). The absence or total exchange in CAA/Cd and CAA/Fe permitted that co-exchange reactions be performed on the unnocupied Acid sities, with Ag ions, forming novel mixed cadmium-silver and iron-silver compounds. These compounds had their stoichiometry determined as Ag0,73Cd0,635Sb2O6.1,5H2O (CAA/Cd/Ag) and Ag1,34Fe0,22Sb2O6.1,5H2O (CAA/Fe/Ag). Our results show the existence of correlations between the extention of ionic exchange and the structural characteristics of the compounds. Inclusion reactions of NH3, CH3NH2 and CH3CH2NH2 were also performed with CAA. These amines become protonated when they are put to contact with CAA in their vapour state, and studiedby the techniques mentioned previously. It is concluded that these amines become chemically bonded to the pyrochlore structure. CAA, the ion-exchange and inclusion compounds, were heated at various temperatures, and the resulting products were characterized. The results indicate that these products were have interesting characteristics, such as semiconducting ceramic powders, ionic conductors and catalysts. When compared to traditional obtention routes, these preparations show various advantages. Compounds with potential tecnological applications were also obtained by thermal treatment of the mixed compounds CAA/Cd/Ag and CAA/Fe/Ag. The products formed in the thermal decomposition of the ion exchange obtained compounds reveal a new synthetic route for new materiaIs. AlI these results have given us a better comprehension about the structural factors that act in the process of ion exchange between CAA and the different cations studied

  • Quimica do estado solido : sintese, caracterização e decomposição termica do Acido Antimonico cristalino e derivados
    Universidade Estadual de Campinas . Instituto de Quimica, 1993
    Co-Authors: Aldo Jose Gorgatti Zarbin
    Abstract:

    Neste trabalho o Ácido Antimônico Cristalino (AAC), caracterizado como H2Sb2O6.1,5H2O, foi sintetisado pela oxidação do Sb2O3 por uma solução de H2O2. Este composto comporta-se como trocador iônico e, através de dados obtidos por difração de raios-X, observou-se que ele possui a estrutura do tipo do mineral pirocloro. Tal estrutura é característica de compostos com estequiometria A2B2O6O', onde A e B são metais. Através de espectrometria infravermelho, concluiu-se que a espécie trocável do AAC apresenta-se na forma de H3O, e ocupa a posição estrutural do átomo A. Foram realizadas reações de troca tônica do AAC com íons Ag, Cd, Pb e Fe, sendo os compostos obtidos foram caracterizados por análise química, difratometria de raios-X (DRX) , espectroscopia infravermelho (EIV), análise termogravimétrica (ATG), calorimetria diferencial de varredura (CDV) e microscopia eletrônica de varredura (MEV). Os resultados obtidos a partir de todas estas técnicas indicaram que a troca iônica ocorre com diferentes seletividades para estes íons, de tal maneira que Ag e Pb ocorrem com troca total, e Cd e Fe apresentam troca parcial. A estrutura tipo pirocloro não é destruida com a troca iônica, e comparações realizadas entre os difratogramas de raios-X de compostos obtidos por troca iônica com diferentes proporções de íons Ag e os calculados, pelo programa Lazy-Pulverix, indicaram que a troca iônica no AAC ocorre topoquimicamente, no sítio A da estrutura pirocloro. Os compostos trocados com Ag, Cd, Pb e Fe foram caracterizados, respectivamente, como: Ag2Sb2O6.1,0H2O (AAC/Ag), H0,73Cd0,635Sb2O6.1,5H2O (AAC/Cd), PbSb2O6.1,0H2O (AAC/Pb) e H1,34Fe0,22Sb2O6.1,5H2O (AAC/Fe). A ausência de troca total no AAC/Cd e AAC/Fe permitiu que os sítios não ocupados pelo íon metálico fossem submetidos à nova reação de troca (co-troca iônica), com íons Ag, formando compostos mistos originais de cádmio e prata e de ferro e prata. A estequiometria dos produtos formados foi determinada como sendo Ag0,73Cd0,635Sb2O6.1,5H2O (AAC/Cd/Ag) e Ag1,34Fe0,22Sb2O6.1,5H2O (AAC/Fe/Ag). Os dados obtidos permitiram-nos considerar uma correlação entre a extensão da troca iônica e as características estruturais dos compostos. Foram realizadas, ainda, reações de inclusão de NH3, CH3NH2 e CH3CH2NH2 no AAC. Através das técnicas já citadas, observou-se que estas aminas, quando colocadas em contacto com o AAC, no estado gasoso, são protonadas pelos sítios ácidos do AAC, ficando ligadas quimicamente à sua estrutura. O AAC, bem como todos os seus derivados obtidos por troca iônica e reações de inclusão, foram tratados à várias temperaturas, e as fases formadas foram caracterizadas. Os resultados obtidos indicaram que materiais com características interessantes e variadas, como pós cerâmicos semicondutores, condutores iônicos e catalisadores, são obtidos pelo aquecimento dos derivados do AAC. Quando comparado com os métodos tradicionais de obtenção destes materiais, tais preparações apresentaram várias vantagens. Além disso, detectou-se a formação de compostos com aplicação potencial, pelo aquecimento dos derivados mistos AAC/Cd/Ag e AAC/Fe/Ag. As fases formadas pela decomposição térmica dos derivados do AAC revelou uma nova rota de síntese para materiais, além de permitir uma boa compreensão dos fatores estruturais envolvidos no processo de troca iônica do AAC com os cátions estudados.In this work, Cristalline Antimonic Acid (CAA), characterized as H2Sb2O6.1,5H2O, was sinthesized through the oxidation of Sb2O3 by a solution of H2O2. This substance behaves has an ionic exchanger, and it has been determined by X-ray diffraction that it has a structure similar to that of the mineral pyrochlore, A2B2O6O', where A and B are metaIs. From infrared spectroscopy, it was shown that the exchangeable species in CAA is H3O, occuping the A structural position. Ion exchange reactions of CAA were performed with the ions Ag, Cd, Pb and Fe, and the resulting products were characterized using the following techiniques: chemical analysis, X-ray diffraction (XRD), infrared spectroscopy (IS), thermogravimetric analysis (TGA) , differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). All the results indicate that ion exchange occurs with different selectivities depending on the exchanged cation. Ag and Pb represents total exchanges, while for Cd and Fe, partial exchanges where observed. The pyrochlore structure is not affected by the exchange, and the comparison between experimental X-ray diffratograms of the Ag exchanged products with different Ag quantities and calculated obtained using the Lazy-Pulverix program indicates that the exchange occurs topochemically at the A sities or the pyrochlore structure. The Ag, Cd, Pb and Fe exchanged compounds where characterized respectively as: Ag2Sb2O6.1,0H2O (CAA/Ag), H0,73Cd0,635Sb2O6.1,5H2O (CAA/Cd), PbSb2O6.1,0H2O (CAA/Pb) and H1,34Fe0,22Sb2O6.1,5H2O (CAA/Fe). The absence or total exchange in CAA/Cd and CAA/Fe permitted that co-exchange reactions be performed on the unnocupied Acid sities, with Ag ions, forming novel mixed cadmium-silver and iron-silver compounds. These compounds had their stoichiometry determined as Ag0,73Cd0,635Sb2O6.1,5H2O (CAA/Cd/Ag) and Ag1,34Fe0,22Sb2O6.1,5H2O (CAA/Fe/Ag). Our results show the existence of correlations between the extention of ionic exchange and the structural characteristics of the compounds. Inclusion reactions of NH3, CH3NH2 and CH3CH2NH2 were also performed with CAA. These amines become protonated when they are put to contact with CAA in their vapour state, and studiedby the techniques mentioned previously. It is concluded that these amines become chemically bonded to the pyrochlore structure. CAA, the ion-exchange and inclusion compounds, were heated at various temperatures, and the resulting products were characterized. The results indicate that these products were have interesting characteristics, such as semiconducting ceramic powders, ionic conductors and catalysts. When compared to traditional obtention routes, these preparations show various advantages. Compounds with potential tecnological applications were also obtained by thermal treatment of the mixed compounds CAA/Cd/Ag and CAA/Fe/Ag. The products formed in the thermal decomposition of the ion exchange obtained compounds reveal a new synthetic route for new materiaIs. AlI these results have given us a better comprehension about the structural factors that act in the process of ion exchange between CAA and the different cations studied

Guntars Vaivars - One of the best experts on this subject based on the ideXlab platform.

  • Recent advances in electrochromics for smart windows applications
    Solar Energy, 1998
    Co-Authors: Claes-göran Granqvist, D. Rönnow, M. Strømme Mattsson, M. Veszelei, Danniel Ronnow, Anna Hjelm, Andris Azens, Leif Kullman, Gunnar A. Niklasson, Guntars Vaivars
    Abstract:

    Electrochromic smart windows are able to vary their throughput of radiant energy by low-voltage electrical pulses. This function is caused by reversible shuttling of electrons and charge balancing ions between an electrochromic thin film and a transparent counter electrode. The ion transport takes place via a solid electrolyte. Charge transport is evoked by a voltage applied between transparent electrical conductors surrounding the electrochromic film/electrolyte/counter electrode stack. This review summarizes recent progress concerning: (i) calculated optical properties of crystalline WO3, (ii) electrochromic properties of heavily disordered W oxide and oxyfluoride films produced by reactive magnetron bias sputtering, (iii) novel transparent reactively sputter-deposited Zr-Ce oxide counter electrodes and (iv) a new proton-conducting Antimonic-Acid-based polymer electrolyte. Special in depth presentations are given on elastic light scattering from W-oxide-based films and of electronic band structure effects affecting opto-chronopotentiometry data in Zr-Ce oxide. The review also contains some new device data for an electrochromic smart window capable of very high optical transmittance.

Beleze,fábio A. - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis and characterization of organic-inorganic hybrids formed between conducting polymers and crystalline Antimonic Acid
    Sociedade Brasileira de Química, 2001
    Co-Authors: Beleze,fábio A., Zarbin,aldo J. G.
    Abstract:

    In this paper we report the synthesis and characterization of novel organic-inorganic hybrid materials between the crystalline Antimonic Acid (CAA) and two conductive polymers: polypyrrole and polyaniline. The hybrids were obtained by in situ oxidative polymerization of monomers by the Sb(V) present in the pyrochlore-like CAA structure. The materials were characterized by infrared and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, CHN elemental analysis and electronic paramagnetic resonance spectroscopy. The results showed that both polymers were formed in their oxidized form, with the CAA structure acting as a counter anion

  • Synthesis and characterization of organic-inorganic hybrids formed between conducting polymers and crystalline Antimonic Acid
    Sociedade Brasileira de Química, 2001
    Co-Authors: Beleze,fábio A., Zarbin,aldo J. G.
    Abstract:

    In this paper we report the synthesis and characterization of novel organic-inorganic hybrid materials between the crystalline Antimonic Acid (CAA) and two conductive polymers: polypyrrole and polyaniline. The hybrids were obtained by in situ oxidative polymerization of monomers by the Sb(V) present in the pyrochlore-like CAA structure. The materials were characterized by infrared and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, CHN elemental analysis and electronic paramagnetic resonance spectroscopy. The results showed that both polymers were formed in their oxidized form, with the CAA structure acting as a counter anion.Neste trabalho são relatadas e discutidas a síntese e a caracterização de dois materiais híbridos orgânico-inorgânico, formados entre o ácido antimônico cristalino (AAC), como fração inorgânica, e dois polímeros condutores (polipirrol e polianilina) como fração orgânica. Os híbridos foram obtidos a partir da polimerização oxidativa in situ dos monômeros, utilizando-se o próprio AAC como agente oxidante, a partir da redução dos átomos de Sb(V) presentes em sua estrutura. Os materiais foram caracterizados por espectroscopias infravermelho e Raman, voltametria cíclica, difratometria de raios-X, análise elementar CHN e espectroscopia de ressonância paramagnética eletrônica. Os resultados evidenciaram que ambos os polímeros foram formados em sua forma oxidada, com a própria estrutura do AAC atuando como contra-íon

Claes-göran Granqvist - One of the best experts on this subject based on the ideXlab platform.

  • Recent advances in electrochromics for smart windows applications
    Solar Energy, 1998
    Co-Authors: Claes-göran Granqvist, D. Rönnow, M. Strømme Mattsson, M. Veszelei, Danniel Ronnow, Anna Hjelm, Andris Azens, Leif Kullman, Gunnar A. Niklasson, Guntars Vaivars
    Abstract:

    Electrochromic smart windows are able to vary their throughput of radiant energy by low-voltage electrical pulses. This function is caused by reversible shuttling of electrons and charge balancing ions between an electrochromic thin film and a transparent counter electrode. The ion transport takes place via a solid electrolyte. Charge transport is evoked by a voltage applied between transparent electrical conductors surrounding the electrochromic film/electrolyte/counter electrode stack. This review summarizes recent progress concerning: (i) calculated optical properties of crystalline WO3, (ii) electrochromic properties of heavily disordered W oxide and oxyfluoride films produced by reactive magnetron bias sputtering, (iii) novel transparent reactively sputter-deposited Zr-Ce oxide counter electrodes and (iv) a new proton-conducting Antimonic-Acid-based polymer electrolyte. Special in depth presentations are given on elastic light scattering from W-oxide-based films and of electronic band structure effects affecting opto-chronopotentiometry data in Zr-Ce oxide. The review also contains some new device data for an electrochromic smart window capable of very high optical transmittance.