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Volume 42 (2015)
- Issue 4 Pages 130-
- Issue 3 Pages 81-
- Issue 2 Pages 47-
- Issue 1 Pages 1-
Volume 42, Issue 3
Displaying 1-6 of 6 articles from this issue
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Review
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Shinya Otsuka-Yao-Matsuo, Tomohiro Ishiyama, Masao Kita2015 Volume 42 Issue 3 Pages 81-89
Published: July 25, 2015
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSThe effect of the mixing states of CaF2-like phases appearing in the Zr-Ce-Pr-O system on their thermochemical behavior has been discussed on the basis of the data accumulated over the past few decades. In the Pr-O system, a series of CaF2-like PrnO2n-2: Pr3+4Pr4+mO2(4+m)-2 oxides are well-known; the metastable phase (m = 4) may appear in a mixing state with the m = 5 or 3 phase for the PrnO2n-2 thin film sputtered on a CaF2-related Y2O3 substrate. In the Zr-Ce-O system, there exist many CaF2-like and -related phases: tetragonal t, t', t'', cubic c, κ-Ce2Zr2O8, and so on. In the Zr-Pr-O system, the novel CaF2-type λ-(Zr1/4Pr3/4)O2-y phase with large oxygen nonstoichiometry has been discovered. For the quasi-binary solid solutions, Zr2/8Ce(6-x/8)Prx/8O2-y (0≤x≤6), the (c, t'') and λ phases appear in the Ce-rich and Pr-rich regions, respectively. The extremely resembling c, t'' and λ phases can form junctions with coherent interfaces, accompanied by introduction of oxygen vacancy around them, when the samples pre-fired at a sufficiently high temperature. The most excellent results for CH4 steam reforming test have been obtained with Ni catalyst supported by the oxides possessing the junctions; the catalytic activity of NiO has been reported.View full abstractDownload PDF (2533K) -
Ayako Nitta, Takeshi Morita2015 Volume 42 Issue 3 Pages 90-96
Published: July 25, 2015
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSSome aqueous solutions of ionic liquids exhibit liquid-liquid phase transition with upper or lower critical solution temperatures. Aqueous solutions of [C4mim]BF4 and [P4444]CF3COO are examples for the solutions which show UCST-type and LCST-type phase transitions, respectively. Hydrophobicity and hydrophilicity of the constituent ions of the ionic liquids can be characterized in terms of their effects on molecular organization of H2O based on the 1-propanol probing methodology. The contributions of hydrophobicity/hydrophilicity are evaluated based on the third derivatives of the Gibbs energy. Amphiphilicity is defined as combination of the effects of hydrophobicity and hydrophilicity. Constituent ions composed of ionic liquids basically show amphiphilicity with strongly hydrophobic and equally hydrophilic contributions. The self-aggregation behavior of the cations in aqueous solutions is also discussed based on the third derivatives of the Gibbs energy. Furthermore, we introduce the fluctuation of mixing state in aqueous solutions of the ionic liquid, such as aqueous solution of [P4444]CF3COO. Aggregation aspect in the solutions is discussed in terms of inhomogeneity of molecular distribution. It is suggested that the evaluated hydrophobicity/hydrophilicity could be related to the mixing state even in the higher concentration range.View full abstractDownload PDF (1679K) -
Masao Fujisawa2015 Volume 42 Issue 3 Pages 97-103
Published: July 25, 2015
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSDetermining accurate quantitative values for the changes in the thermodynamic functions caused by molecular inclusion in the liquid phase is essential, since the thermodynamic functions constitute basic information required for understanding the mechanisms of molecular recognition and discrimination. In this study, ideal gas phase enthalpies, entropies, and Gibbs free energies of the inclusion of alcohols and diols into cyclodextrin (CyD) cavities were determined on the basis of experimentally measured calorimetry data and hydration thermodynamic functions. Hydration Gibbs energies of guest molecules were predicted using the SM8 model with dispersion-corrected density functionals. To clarify details related to the interaction energies of β-CyD-drug complexes, pair interaction energy decomposition analysis (PIEDA) was carried out. Further, in order to reveal the mechanism involved in the inclusion phenomenon in these complexes, binding free energies were determined using a molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) analysis. By examining three-body interactions with the molecular orbital method, the differences between homochiral interactions and heterochiral interactions were found to correspond to the excess enthalpies of mixing of the enantiomers. The relationship between molecular interactions and changes in thermodynamic quantities examined by precise microcalorimetry has been reinforced using computational chemistry methods.View full abstractDownload PDF (955K) -
Naoya Inomata, Yuko Nishimoto2015 Volume 42 Issue 3 Pages 104-109
Published: July 25, 2015
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSThe volatile organic compounds (VOC) adsorption and VOC desorption properties of charcoals, woodceramics and steam activated charcoals prepared from various source biomasses were characterized by thermal analysis. VOC adsorption properties were evaluated by the rapid method for VOC evolved from wood materials using TG and headspace GC. VOC desorption properties were evaluated by EGA-Ion Attachment-MS. A wide range in VOC adsorption and VOC desorption properties was observed, and was correlated with source materials and carbonized temperatures.View full abstractDownload PDF (1418K) -
Shuzo Ohe2015 Volume 42 Issue 3 Pages 110-118
Published: July 25, 2015
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSAn overview of prediction methods for thermophysical properties in chemical engineering is presented. As thermophysical properties, molar enthalpy, enthalpy of vaporization, and thermal conductivity are selected. The author categorized the prediction methods into three categories shown as follows: I. Method based on principle of physical chemistry, II. Method based on group contribution of molecular structure, III. Method based on corresponding state principle. Almost all the prediction methods are empirical modifications of the theory of physical chemistry. Empirical extension of theory can often lead to a method useful for prediction purposes. Prediction of enthalpy of vaporization from vapor pressure has been examined by using Antoine constants determined by the author for toluene with satisfactory results. Thermal conductivity of toluene is important, since toluene is standard substance for thermal conductivity observation. One of the latest group contribution method by Müller and Arlt (2014)20) is adopted for the prdiction of thermal conductivity of toluene. It is useful prediction method which can predict gas as well as liquid thermal conductivity. The result of prediction is satisfactory with error of -7.18%.View full abstractDownload PDF (1462K)
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2015 Volume 42 Issue 3 Pages 119-121
Published: July 25, 2015
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSDownload PDF (658K)
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