The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Keith D. Beyer - One of the best experts on this subject based on the ideXlab platform.
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Solid/Liquid phase diagram of the ammonium sulfate/Malonic Acid/water system.
The journal of physical chemistry. A, 2010Co-Authors: Keith D. Beyer, Jason Schroeder, Benjamin PaletAbstract:We have studied the thermodynamic properties of the ammonium sulfate/Malonic Acid/water system using differential scanning calorimetry and infrared spectroscopy of thin films. Using the results from our experiments and literature data, we have created a solid/liquid phase diagram of the ammonium sulfate/Malonic Acid/water system for temperatures below 300 K. We also compare our results to the predictions of the aerosol inorganics model (AIM).
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Experimentally Determined Thermochemical Properties of the Malonic Acid/Water System: Implications for Atmospheric Aerosols
The Journal of Physical Chemistry A, 2004Co-Authors: Anne R. Hansen, Keith D. BeyerAbstract:The liquid/solid phase diagram, solution heat capacities, water activities, enthalpies of fusion, and eutectic temperature of the Malonic Acid/water binary system have been investigated using differential scanning calorimetry and infrared (IR) spectroscopy of thin films. We report here measurements of the ice melting envelope, Malonic Acid dissolution envelope, and the ice/Malonic Acid eutectic temperature and composition in this binary system. We also report the first observation of a Malonic Acid hydrate, possibly C3H4O4·6H2O, using both thermal analysis and IR spectroscopy. We have observed the formation of this hydrate over a large range of concentrations and determined that it can be a significant fraction of samples within that region. We have also determined the enthalpy of fusion of Malonic Acid, as well as the constant pressure heat capacities of solutions in the concentration range of 5−55 wt % Malonic Acid from 323 K down to the freezing point of each solution. Water activities have also been d...
Benjamin Palet - One of the best experts on this subject based on the ideXlab platform.
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Solid/Liquid phase diagram of the ammonium sulfate/Malonic Acid/water system.
The journal of physical chemistry. A, 2010Co-Authors: Keith D. Beyer, Jason Schroeder, Benjamin PaletAbstract:We have studied the thermodynamic properties of the ammonium sulfate/Malonic Acid/water system using differential scanning calorimetry and infrared spectroscopy of thin films. Using the results from our experiments and literature data, we have created a solid/liquid phase diagram of the ammonium sulfate/Malonic Acid/water system for temperatures below 300 K. We also compare our results to the predictions of the aerosol inorganics model (AIM).
Zoltán Noszticzius - One of the best experts on this subject based on the ideXlab platform.
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Contribution to the chemistry of the Belousov-Zhabotinsky reaction. Products of the Ferriin-BromoMalonic Acid and the Ferriin-Malonic Acid reactions.
The journal of physical chemistry. A, 2006Co-Authors: László József Hegedüs, Horst Dieter Försterling, Lavinia Onel, Maria Wittmann, Zoltán NoszticziusAbstract:In the present mechanistic schemes of the ferroin-catalyzed oscillatory Belousov-Zhabotinsky (BZ) reaction the oxidation of the organic substrates (bromoMalonic or Malonic Acid) by ferriin (the oxidized form of the catalyst) plays an important role. As the organic products of these reactions were not yet identified experimentally, they were studied here by an HPLC technique. It was found that the main organic oxidation product of bromoMalonic Acid is bromo-ethene-tricarboxylic Acid (BrEETRA), the same compound that is formed when bromoMalonic Acid is oxidized by Ce4+ (another catalyst of the BZ reaction). Formation of BrEETRA is explained here by a new mechanism that is more realistic than the one suggested earlier. To find any oxidation product of Malonic Acid in the ferriin-Malonic Acid reaction was not successful, however. Neither ethane-tetracarboxylic Acid (ETA) nor malonyl malonate (MAMA), the usual products of the Ce4+- Malonic Acid reaction, nor any other organic Acid, not even CO2, was found as a product of the reaction. We propose that Malonic Acid is not oxidized in the ferriin-Malonic Acid reaction, and it plays only the role of a complex forming catalyst in a process where Fe3+ oxidizes mostly its phenantroline ligand.
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HPLC studies on the photochemical formation of free radicals from Malonic Acid
The Journal of Physical Chemistry A, 1998Co-Authors: István Szalai, Horst Dieter Försterling, Zoltán NoszticziusAbstract:In the Belousov Zhabotinsky reaction, malonyl radicals formed during the oxidation of Malonic Acid by Ce4+ play an important role in the mechanism of the negative feedback loop. In the past, we have analyzed the end products in the Ce4+−Malonic Acid reaction applying HPLC technique. For comparison, we generated malonyl radicals by UV irradiation of solutions of Malonic Acid and we identified the reaction products. Two of these are the same as in the Ce4+−Malonic Acid reaction, but some additional products are also formed. To explain our experimental results, a new reaction path is proposed where malonyl radicals and hydrogen atoms are the first intermediates in the photochemical decomposition of the Malonic Acid. Mechanistic differences between this photochemical decomposition and the Ce4+−Malonic Acid reaction are also discussed.
Pál Jedlovszky - One of the best experts on this subject based on the ideXlab platform.
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Molecular dynamics simulations of the water adsorption around Malonic Acid aerosol models
Physical chemistry chemical physics : PCCP, 2013Co-Authors: Mária Darvas, Sylvain Picaud, Pál JedlovszkyAbstract:Water nucleation around a Malonic Acid aggregate has been studied by means of molecular dynamics simulations in the temperature and pressure range relevant for atmospheric conditions. Systems of different water contents have been considered and a large number of simulations have allowed us to determine the phase diagram of the corresponding binary Malonic Acid–water systems. Two phases have been evidenced in the phase diagrams corresponding either to water adsorption on a large Malonic Acid grain at low temperatures, or to the formation of a liquid-like mixed aggregate of the two types of molecules, at higher temperatures. Finally, the comparison between the phase diagrams simulated for Malonic Acid–water and oxalic Acid–water mixtures emphasizes the influence of the O : C ratio on the hydrophilic behavior of the aerosol, and thus on its ability to act as a cloud condensation nucleus, in accordance with recent experimental conclusions.
Jc Jaap Schouten - One of the best experts on this subject based on the ideXlab platform.
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Kinetics of Malonic Acid degradation in aqueous phase over Pt/graphite catalyst
Applied Catalysis B: Environmental, 2005Co-Authors: Zpg Masende, Bfm Ben Kuster, Kj Krzysztof Ptasinski, Fjjg Frans Janssen, Jhy Katima, Jc Jaap SchoutenAbstract:This work aims at describing quantitatively the catalytic decarboxylation of Malonic Acid over a 5.0 wt.% Pt/graphite catalyst. The study was carried out using a slurry phase continuous flow stirred slurry reactor (CSTR) at a temperature range of 120–160 °C and at a reactor pressure of 1.8 MPa. The conversion of Malonic Acid during catalytic oxidation was found to proceed via decarboxylation to CO2 and acetic Acid, and also oxidation to CO2 and H2O. No indication of deactivation of the platinum catalyst was observed at a maximum residual oxygen pressure in the reactor up to 150 kPa. A reaction mechanism involving elementary steps has been suggested to explain the decarboxylation and oxidation of Malonic Acid. A kinetic model that accounts for both non-catalysed and catalysed decarboxylation of Malonic Acid has been developed and validated. The non-catalysed reaction is first order in Malonic Acid. The activation energies and adsorption enthalpies have been determined. The model is able to describe the experimental data adequately.