Phenylenediamine

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 41508 Experts worldwide ranked by ideXlab platform

Irina Sapurina - One of the best experts on this subject based on the ideXlab platform.

  • oxidation of aniline with silver nitrate accelerated by p Phenylenediamine a new route to conducting composites
    Macromolecules, 2010
    Co-Authors: Patrycja Bober, Jan Prokes, Jaroslav Stejskal, Miroslava Trchova, Irina Sapurina
    Abstract:

    The reaction between two nonconducting compounds, aniline and silver nitrate, yields a composite of two conducting products, PANI and silver. While the oxidation of aniline with silver nitrate is slow and takes over several months, the addition of a small amount of p-Phenylenediamine, 1 mol % relative to aniline, shortens the reaction time to a few hours and, with higher concentrations of p-Phenylenediamine, even to tens of minutes. Nonconducting aniline oligomers, however, are also present in the oxidation products as a rule. The chemistry of individual oxidation pathways is discussed. Higher concentrations of p-Phenylenediamine in the reaction mixture with aniline give rise to copolymers, poly[aniline-co-(p-Phenylenediamine)]s, and their composites with metallic silver. p-Phenylenediamine alone can similarly be oxidized with silver nitrate to poly(p-Phenylenediamine) composite with silver. Silver is present in the composites both as nanoparticles of ∼50 nm size and as larger objects. The composites have...

Patrycja Bober - One of the best experts on this subject based on the ideXlab platform.

  • Cytotoxicity of poly( p -Phenylenediamine)
    Chemical Papers, 2016
    Co-Authors: Zdenka Kuceková, Patrycja Bober, Petra Rejmontová, Petr Humpolíček, Věra Kašpárková, Petr Saha, Jaroslav Stejskal
    Abstract:

    Although poly(p-Phenylenediamine) is an electric non-conductor, it exhibits, analogously to conducting polymers, redox activity and could, therefore, find applications in biomedicine. In the current work, the cytotoxicity of poly(p-Phenylenediamine) polymer powder produced by the chemical oxidation of p-Phenylenediamine with ammonium peroxydisulfate in acidic aqueous media has been studied. Primary mouse embryonic fibroblasts were used for this purpose. Interestingly, the standard methods for the determination of polymer cytotoxicity based on international standard EN ISO 10993-5 could not be applied. The reason was the interaction of polymer extracts with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. On the basis of the evaluation of flow cytometry and micrographs taken by fluorescence microscopy on cells treated with extracts of poly(p-Phenylenediamine), it can be concluded that the powder polymer possesses severe cytotoxicity. The results suggest that practical application of the polymer within biomedicine is, at the current state of knowledge, difficult, and modification of the preparation techniques and/or subsequent purification of poly(p-Phenylenediamine) is needed.

  • the oxidative polymerization of p Phenylenediamine with silver nitrate toward highly conducting micro nanostructured silver conjugated polymer composites
    Journal of Polymer Science Part A, 2011
    Co-Authors: Gordana Ciricmarjanovic, Patrycja Bober, Jaroslav Stejskal, Miroslava Trchova, Budimir Marjanovic, Zuzana Rozlivkova, Jan Prokes
    Abstract:

    The oxidative polymerization of p-Phenylenediamine with silver nitrate by using various oxidant/monomer mole ratios in aqueous solutions of both acetic and nitric acid was studied experimentally and computationally. The produced micro/nanostructured conducting poly(p-Phenylenediamine)-silver composites, reaching the conductivities >10 4 S/cm, were characterized by conductivity and density measurements, gel permeation chromatography, transmission electron microscopy, UV-visible, FTIR, and Raman spectroscopies. The highest conductivity was 31,700 S/cm for poly(p-Phenylenediamine) base-silver (81.4 wt % Ag). The unexpected increase of conductivity after deprotonation of polymer component is discussed on the basis of interfacial electrical barriers and their removal. Theoretical study of the mechanism of p-Phenylenediamine oxidation has been based on the AM1 semi-empirical quantum chemical computations of the heat of formation of the reaction intermediates, taking into account the influence of pH and solvation effects. Quantum chemical predictions of molecular structure of poly(p-Phenylenediamine) were correlated with spectroscopic findings.

  • oxidation of aniline with silver nitrate accelerated by p Phenylenediamine a new route to conducting composites
    Macromolecules, 2010
    Co-Authors: Patrycja Bober, Jan Prokes, Jaroslav Stejskal, Miroslava Trchova, Irina Sapurina
    Abstract:

    The reaction between two nonconducting compounds, aniline and silver nitrate, yields a composite of two conducting products, PANI and silver. While the oxidation of aniline with silver nitrate is slow and takes over several months, the addition of a small amount of p-Phenylenediamine, 1 mol % relative to aniline, shortens the reaction time to a few hours and, with higher concentrations of p-Phenylenediamine, even to tens of minutes. Nonconducting aniline oligomers, however, are also present in the oxidation products as a rule. The chemistry of individual oxidation pathways is discussed. Higher concentrations of p-Phenylenediamine in the reaction mixture with aniline give rise to copolymers, poly[aniline-co-(p-Phenylenediamine)]s, and their composites with metallic silver. p-Phenylenediamine alone can similarly be oxidized with silver nitrate to poly(p-Phenylenediamine) composite with silver. Silver is present in the composites both as nanoparticles of ∼50 nm size and as larger objects. The composites have...

Jan Prokes - One of the best experts on this subject based on the ideXlab platform.

  • the oxidative polymerization of p Phenylenediamine with silver nitrate toward highly conducting micro nanostructured silver conjugated polymer composites
    Journal of Polymer Science Part A, 2011
    Co-Authors: Gordana Ciricmarjanovic, Patrycja Bober, Jaroslav Stejskal, Miroslava Trchova, Budimir Marjanovic, Zuzana Rozlivkova, Jan Prokes
    Abstract:

    The oxidative polymerization of p-Phenylenediamine with silver nitrate by using various oxidant/monomer mole ratios in aqueous solutions of both acetic and nitric acid was studied experimentally and computationally. The produced micro/nanostructured conducting poly(p-Phenylenediamine)-silver composites, reaching the conductivities >10 4 S/cm, were characterized by conductivity and density measurements, gel permeation chromatography, transmission electron microscopy, UV-visible, FTIR, and Raman spectroscopies. The highest conductivity was 31,700 S/cm for poly(p-Phenylenediamine) base-silver (81.4 wt % Ag). The unexpected increase of conductivity after deprotonation of polymer component is discussed on the basis of interfacial electrical barriers and their removal. Theoretical study of the mechanism of p-Phenylenediamine oxidation has been based on the AM1 semi-empirical quantum chemical computations of the heat of formation of the reaction intermediates, taking into account the influence of pH and solvation effects. Quantum chemical predictions of molecular structure of poly(p-Phenylenediamine) were correlated with spectroscopic findings.

  • oxidation of aniline with silver nitrate accelerated by p Phenylenediamine a new route to conducting composites
    Macromolecules, 2010
    Co-Authors: Patrycja Bober, Jan Prokes, Jaroslav Stejskal, Miroslava Trchova, Irina Sapurina
    Abstract:

    The reaction between two nonconducting compounds, aniline and silver nitrate, yields a composite of two conducting products, PANI and silver. While the oxidation of aniline with silver nitrate is slow and takes over several months, the addition of a small amount of p-Phenylenediamine, 1 mol % relative to aniline, shortens the reaction time to a few hours and, with higher concentrations of p-Phenylenediamine, even to tens of minutes. Nonconducting aniline oligomers, however, are also present in the oxidation products as a rule. The chemistry of individual oxidation pathways is discussed. Higher concentrations of p-Phenylenediamine in the reaction mixture with aniline give rise to copolymers, poly[aniline-co-(p-Phenylenediamine)]s, and their composites with metallic silver. p-Phenylenediamine alone can similarly be oxidized with silver nitrate to poly(p-Phenylenediamine) composite with silver. Silver is present in the composites both as nanoparticles of ∼50 nm size and as larger objects. The composites have...

  • AC properties of anilineû1,4-Phenylenediamine copolymers
    Synthetic Metals, 2001
    Co-Authors: I. Kr̆ivka, Jan Prokes, O. Starykov, Jaroslav Stejskal
    Abstract:

    The joint chemical oxidation of aniline with various Phenylenediamines yields polyaniline-like materials, electrical properties of which can be controlled on a submolecular level by the composition of reaction mixture. The dependence of the complex permittivity as well as of the dielectric modulus of aniline-1,4-Phenylenediamine copolymers on temperature and frequency were measured on samples with various aniline contents. On the basis of experimental data, a typical energy corresponding to inter-bundle hopping barriers for various copolymer compositions has been estimated. The dependence of a conducting bundle size on composition has also been evaluated.

  • Poly(Phenylenediamine) Dispersions.
    Journal of Colloid and Interface Science, 2001
    Co-Authors: Tetyana Sulimenko, Jaroslav Stejskal, Jan Prokes
    Abstract:

    The formation and properties of poly(Phenylenediamine) colloidal dispersions were investigated. Oxidative dispersion polymerization of 1,3-Phenylenediamine dihydrochloride stabilized with poly(N-vinylpyrrolidone) was taken as a reference experiment. Conductivity, temperature, and acidity of the reaction mixture were recorded during the polymerization. Oxidations of all three Phenylenediamine bases, of corresponding dihydrochlorides, and of dihydrochlorides in excess acid are compared. The effect of the nature of steric stabilizer on the course of polymerization was found to be marginal. Dispersion polymerization was observed to proceed faster than the precipitation one. Dynamic light scattering was used to assess particle sizes in poly(Phenylenediamine) dispersions. The results are discussed in relation to an analogous polymerization of aniline leading to polyaniline dispersions.

  • Aniline-Phenylenediamine copolymers
    Synthetic Metals, 1999
    Co-Authors: Jan Prokes, Jaroslav Stejskal, Ivo Křivka, Eva Tobolková
    Abstract:

    The electrical conductivity of materials based on polyaniline can be controlled on submolecular level by the copolymerization of aniline with various Phenylenediamines. The joint chemical oxidation of aniline with Phenylenediamines yields products with the dc conductivity spanning over more than eleven orders of magnitude. The dependence of the conductivity on the composition of reaction mixture was investigated for all three comonomers, o-, m-, and p-Phenylenediamine. The electrical properties of copolymers and mixtures of corresponding homopolymers are compared.

Miroslava Trchova - One of the best experts on this subject based on the ideXlab platform.

  • the oxidative polymerization of p Phenylenediamine with silver nitrate toward highly conducting micro nanostructured silver conjugated polymer composites
    Journal of Polymer Science Part A, 2011
    Co-Authors: Gordana Ciricmarjanovic, Patrycja Bober, Jaroslav Stejskal, Miroslava Trchova, Budimir Marjanovic, Zuzana Rozlivkova, Jan Prokes
    Abstract:

    The oxidative polymerization of p-Phenylenediamine with silver nitrate by using various oxidant/monomer mole ratios in aqueous solutions of both acetic and nitric acid was studied experimentally and computationally. The produced micro/nanostructured conducting poly(p-Phenylenediamine)-silver composites, reaching the conductivities >10 4 S/cm, were characterized by conductivity and density measurements, gel permeation chromatography, transmission electron microscopy, UV-visible, FTIR, and Raman spectroscopies. The highest conductivity was 31,700 S/cm for poly(p-Phenylenediamine) base-silver (81.4 wt % Ag). The unexpected increase of conductivity after deprotonation of polymer component is discussed on the basis of interfacial electrical barriers and their removal. Theoretical study of the mechanism of p-Phenylenediamine oxidation has been based on the AM1 semi-empirical quantum chemical computations of the heat of formation of the reaction intermediates, taking into account the influence of pH and solvation effects. Quantum chemical predictions of molecular structure of poly(p-Phenylenediamine) were correlated with spectroscopic findings.

  • oxidation of aniline with silver nitrate accelerated by p Phenylenediamine a new route to conducting composites
    Macromolecules, 2010
    Co-Authors: Patrycja Bober, Jan Prokes, Jaroslav Stejskal, Miroslava Trchova, Irina Sapurina
    Abstract:

    The reaction between two nonconducting compounds, aniline and silver nitrate, yields a composite of two conducting products, PANI and silver. While the oxidation of aniline with silver nitrate is slow and takes over several months, the addition of a small amount of p-Phenylenediamine, 1 mol % relative to aniline, shortens the reaction time to a few hours and, with higher concentrations of p-Phenylenediamine, even to tens of minutes. Nonconducting aniline oligomers, however, are also present in the oxidation products as a rule. The chemistry of individual oxidation pathways is discussed. Higher concentrations of p-Phenylenediamine in the reaction mixture with aniline give rise to copolymers, poly[aniline-co-(p-Phenylenediamine)]s, and their composites with metallic silver. p-Phenylenediamine alone can similarly be oxidized with silver nitrate to poly(p-Phenylenediamine) composite with silver. Silver is present in the composites both as nanoparticles of ∼50 nm size and as larger objects. The composites have...

Jaroslav Stejskal - One of the best experts on this subject based on the ideXlab platform.

  • Cytotoxicity of poly( p -Phenylenediamine)
    Chemical Papers, 2016
    Co-Authors: Zdenka Kuceková, Patrycja Bober, Petra Rejmontová, Petr Humpolíček, Věra Kašpárková, Petr Saha, Jaroslav Stejskal
    Abstract:

    Although poly(p-Phenylenediamine) is an electric non-conductor, it exhibits, analogously to conducting polymers, redox activity and could, therefore, find applications in biomedicine. In the current work, the cytotoxicity of poly(p-Phenylenediamine) polymer powder produced by the chemical oxidation of p-Phenylenediamine with ammonium peroxydisulfate in acidic aqueous media has been studied. Primary mouse embryonic fibroblasts were used for this purpose. Interestingly, the standard methods for the determination of polymer cytotoxicity based on international standard EN ISO 10993-5 could not be applied. The reason was the interaction of polymer extracts with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. On the basis of the evaluation of flow cytometry and micrographs taken by fluorescence microscopy on cells treated with extracts of poly(p-Phenylenediamine), it can be concluded that the powder polymer possesses severe cytotoxicity. The results suggest that practical application of the polymer within biomedicine is, at the current state of knowledge, difficult, and modification of the preparation techniques and/or subsequent purification of poly(p-Phenylenediamine) is needed.

  • the oxidative polymerization of p Phenylenediamine with silver nitrate toward highly conducting micro nanostructured silver conjugated polymer composites
    Journal of Polymer Science Part A, 2011
    Co-Authors: Gordana Ciricmarjanovic, Patrycja Bober, Jaroslav Stejskal, Miroslava Trchova, Budimir Marjanovic, Zuzana Rozlivkova, Jan Prokes
    Abstract:

    The oxidative polymerization of p-Phenylenediamine with silver nitrate by using various oxidant/monomer mole ratios in aqueous solutions of both acetic and nitric acid was studied experimentally and computationally. The produced micro/nanostructured conducting poly(p-Phenylenediamine)-silver composites, reaching the conductivities >10 4 S/cm, were characterized by conductivity and density measurements, gel permeation chromatography, transmission electron microscopy, UV-visible, FTIR, and Raman spectroscopies. The highest conductivity was 31,700 S/cm for poly(p-Phenylenediamine) base-silver (81.4 wt % Ag). The unexpected increase of conductivity after deprotonation of polymer component is discussed on the basis of interfacial electrical barriers and their removal. Theoretical study of the mechanism of p-Phenylenediamine oxidation has been based on the AM1 semi-empirical quantum chemical computations of the heat of formation of the reaction intermediates, taking into account the influence of pH and solvation effects. Quantum chemical predictions of molecular structure of poly(p-Phenylenediamine) were correlated with spectroscopic findings.

  • oxidation of aniline with silver nitrate accelerated by p Phenylenediamine a new route to conducting composites
    Macromolecules, 2010
    Co-Authors: Patrycja Bober, Jan Prokes, Jaroslav Stejskal, Miroslava Trchova, Irina Sapurina
    Abstract:

    The reaction between two nonconducting compounds, aniline and silver nitrate, yields a composite of two conducting products, PANI and silver. While the oxidation of aniline with silver nitrate is slow and takes over several months, the addition of a small amount of p-Phenylenediamine, 1 mol % relative to aniline, shortens the reaction time to a few hours and, with higher concentrations of p-Phenylenediamine, even to tens of minutes. Nonconducting aniline oligomers, however, are also present in the oxidation products as a rule. The chemistry of individual oxidation pathways is discussed. Higher concentrations of p-Phenylenediamine in the reaction mixture with aniline give rise to copolymers, poly[aniline-co-(p-Phenylenediamine)]s, and their composites with metallic silver. p-Phenylenediamine alone can similarly be oxidized with silver nitrate to poly(p-Phenylenediamine) composite with silver. Silver is present in the composites both as nanoparticles of ∼50 nm size and as larger objects. The composites have...

  • AC properties of anilineû1,4-Phenylenediamine copolymers
    Synthetic Metals, 2001
    Co-Authors: I. Kr̆ivka, Jan Prokes, O. Starykov, Jaroslav Stejskal
    Abstract:

    The joint chemical oxidation of aniline with various Phenylenediamines yields polyaniline-like materials, electrical properties of which can be controlled on a submolecular level by the composition of reaction mixture. The dependence of the complex permittivity as well as of the dielectric modulus of aniline-1,4-Phenylenediamine copolymers on temperature and frequency were measured on samples with various aniline contents. On the basis of experimental data, a typical energy corresponding to inter-bundle hopping barriers for various copolymer compositions has been estimated. The dependence of a conducting bundle size on composition has also been evaluated.

  • Poly(Phenylenediamine) Dispersions.
    Journal of Colloid and Interface Science, 2001
    Co-Authors: Tetyana Sulimenko, Jaroslav Stejskal, Jan Prokes
    Abstract:

    The formation and properties of poly(Phenylenediamine) colloidal dispersions were investigated. Oxidative dispersion polymerization of 1,3-Phenylenediamine dihydrochloride stabilized with poly(N-vinylpyrrolidone) was taken as a reference experiment. Conductivity, temperature, and acidity of the reaction mixture were recorded during the polymerization. Oxidations of all three Phenylenediamine bases, of corresponding dihydrochlorides, and of dihydrochlorides in excess acid are compared. The effect of the nature of steric stabilizer on the course of polymerization was found to be marginal. Dispersion polymerization was observed to proceed faster than the precipitation one. Dynamic light scattering was used to assess particle sizes in poly(Phenylenediamine) dispersions. The results are discussed in relation to an analogous polymerization of aniline leading to polyaniline dispersions.