Netsu Sokutei
Online ISSN : 1884-1899
Print ISSN : 0386-2615
ISSN-L : 0386-2615
Search
Advanced search
OR
Browse
Search
Volume 51, Issue 4
Displaying 1-6 of 6 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Review
  • Preparation of Li3NaSiO4 Powder with High Purity and Its CO2 Absorption/Desorption Mechanism and Cyclic Property
    Shumpei Iwasaki, Manami Hirai, Kosuke Shido, Takuya Hashimoto
    2024 Volume 51 Issue 4 Pages 141-147
    Published: October 25, 2024
    Released on J-STAGE: February 07, 2025
    DOIhttps://doi.org/10.11311/jscta.51.4_141
    JOURNAL RESTRICTED ACCESS
    Show abstractHide abstract
    The potential of Li3NaSiO4 as CO2 absorption/desorption material was investigated. Preparation mechanism of Li3NaSiO4 by solid state reaction method was analyzed by thermal analyses. Li3NaSiO4 powder with high purity was successfully obtained by solid state reaction of Li4SiO4, Li2SiO3 and Na2CO3 without generation of liquid phase of LiNaCO3 during heat-treatment. It was proposed that Li3NaSiO4 layer with thickness of ~1 μm formed at interface between liquid LiNaCO3 and solid Li2SiO3 prevented CO2 desorption reaction; however, stable cyclic property of CO2 absorption/desorption with 20 times by alternate changing of CO2 and N2 gas at high temperature was successfully observed in Li3NaSiO4 because form of Li2SiO3 generated at CO2 absorption reaction by Li3NaSiO4 was needle-like with short edge of ~2 μm, which was small enough to complete CO2 desorption reaction. The cyclic property by alternate changing of 10% CO2/N2 and N2 was also obtained at 650 ºC, which was optimized using the pseudo van’t-Hoff plot prepared from TG curves of Li2SiO3 and LiNaCO3mixture under various CO2 partial pressures, indicating high potential of Li3NaSiO4 for practical application.
    View full abstract
    Download PDF (3778K)
  • Detection of Conformational Changes of G4 Aptamer in the Presence of Different Cations using Calorimetry
    Elisa-Sudo Tomita, Taku Ishigaki, Masako Hirose, Maki Kato, Junji Kawa ...
    2024 Volume 51 Issue 4 Pages 148-152
    Published: October 25, 2024
    Released on J-STAGE: February 07, 2025
    DOIhttps://doi.org/10.11311/jscta.51.4_148
    JOURNAL RESTRICTED ACCESS
    Show abstractHide abstract
    Nucleic acids are biopolymers that play a significant role in living organisms. The main role of nucleic acids is to store genetic information, however, there are also nucleic acids with functions, such as ribozymes and aptamers. As well as proteins, the function of nucleic acids is determined by higher-order structure. Therefore, it is essential to know the higher-order structure of nucleic acids for understanding the mechanisms of biological activities. Higher order structure is determined not only by nucleotide sequence but also by the external environment of the nucleic acid, i.e. the conditions of the solution in which the nucleic acid is solved. In this study, we focused on the effect of the external environment on the higher-order structure of nucleic acids and aimed to devise a new measurement method that can detect it. From our data, it was successfully detected by ITC that the G4 structure changes depending on environmental changes. If this method can be applied to various solution conditions, it should be possible to observe changes in the higher-order structure in response to more diverse environmental changes.
    View full abstract
    Download PDF (1027K)
  • Thermal Property Enhancement of Biopolyesters by Controlling Molecular Structure and Processing Conditions
    Daisuke Ishii
    2024 Volume 51 Issue 4 Pages 153-159
    Published: October 25, 2024
    Released on J-STAGE: February 07, 2025
    DOIhttps://doi.org/10.11311/jscta.51.4_153
    JOURNAL RESTRICTED ACCESS
    Show abstractHide abstract
    In order to enhance thermal properties of biomass plastics, i.e., plastics made from plant biomasses, modification of backbone structure and processing conditions have been attempted. As the modification of backbone structure, utilization of cinnamic acid derivatives in the polyester was found effective to enhance the glass transition and degradation temperatures. In particular, utilization of ferulic acid led to express liquid crystalline nature. As the modification of processing conditions, utilization of polysaccharide derivatives as the nucleating agent of poly(lactide) stereocomplex was attempted. As the result, enhanced stereocomplex formation without homocrystal formation after the isothermal crystallization below the melting point of homocrystal was attained.
    View full abstract
    Download PDF (1676K)
  • Heterogeneous Adsorbed Film Formation and Line Tension at Oil/Water Interfaces
    Takanori Takiue
    2024 Volume 51 Issue 4 Pages 160-165
    Published: October 25, 2024
    Released on J-STAGE: February 07, 2025
    DOIhttps://doi.org/10.11311/jscta.51.4_160
    JOURNAL RESTRICTED ACCESS
    Show abstractHide abstract
    Condensed domain formation of surface active substances in adsorbed films at alkane/water interfaces was investigated by interfacial tensiometry, X-ray reflectometry, and BAM observation. The results obtained are explained by the effects of contact energy and dipole-dipole interaction, which are competitive contributions to the line tension acting at the domain boundary. It was suggested that the contact energy is predominant in the domains formed during the phase transition in the adsorbed film of cationic surfactant. In the mixed adsorbed film of cationic surfactant and cholesterol, small domain formation due to the effects of low contact energy and dipole-dipole interaction was observed. In the adsorbed films of fluorinated alcohol, F8H2OH, at alkane/water interfaces, the domain formation was suppressed with increasing alkane chain length due to an increase in contact energy. The mixing of hybrid alcohol with fluorocarbon and hydrocarbon chains of the same carbon number, F6H6OH, in adsorbed film reduces contact energy. This stabilizes the dispersion of many domains with small size. On the other hand, when F8H2OH molecules are mixed with a cationic surfactant, C12TAB, in the adsorbed film, an attractive dipole-ion interaction between the hydrophilic groups relaxes the repulsive dipole-dipole interaction between F8H2OH molecules, resulting in the formation of domains with smooth boundary and large size. Furthermore, fluorinated ester, FC12Me molecules form flower shaped domains with intricate boundary mainly due to a larger dipole moment of FC12Me than F8H2OH.
    View full abstract
    Download PDF (1714K)
  • Structure and Dielectric Properties of Crystals with Second-Order Ferroelectric Phase Transitions
    Yukana Terasawa, Toshio Kikuta
    2024 Volume 51 Issue 4 Pages 166-171
    Published: October 25, 2024
    Released on J-STAGE: February 07, 2025
    DOIhttps://doi.org/10.11311/jscta.51.4_166
    JOURNAL RESTRICTED ACCESS
    Show abstractHide abstract
    Dielectrics are materials with dielectric polarization and paraelectricity, and exhibit various properties depending on external field, stress, and heat. Among them, ferroelectrics are materials that can reverse the direction of spontaneous polarization by an electric field. Ferroelectrics undergo a structural phase transition at a certain temperature due to a change in the symmetry of the crystal structure. Ferroelectric phase transitions are classified according to changes in the physical properties that characterize the ferroelectric material with respect to temperature. In this paper, we measure the crystal structure and dielectric properties of ferroelectrics undergoing a second-order structural phase transition and explain the experimental results using phenomenology.
    View full abstract
    Download PDF (1112K)
Help Keywords
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top