Netsu Sokutei
Online ISSN : 1884-1899
Print ISSN : 0386-2615
ISSN-L : 0386-2615
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Volume 46, Issue 4
Displaying 1-10 of 10 articles from this issue
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Review
  • Utilization of Thermal Analysis in Polymer Material Development
    Kazuhiko Ishikiriyama
    2019 Volume 46 Issue 4 Pages 155-162
    Published: October 15, 2019
    Released on J-STAGE: November 20, 2022
    DOIhttps://doi.org/10.11311/jscta.46.4_155
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    In the research and development (R&D) of macromolecules, various problems have been solved, and in order to solve them, thermal analysis, which can provide the whole image regarding bulk information, plays an important role in enterprises. In particular, differential scanning calorimetry (DSC) was introduced to the R&D field of the polymer industry as soon as it was developed since it is accompanied by heating and cooling in moulding and manufacturing process. It has been also utilized for the analysis of higher order processes for fibres or films. In addition, the advent of temperature-modulated DSC (TMDSC) has made the analysis of amorphous structures of macromolecules possible. Moreover, fast scan calorimetry (FSC) has made it possible to simulate the actual method of processing at higher scanning rates during heating or cooling, and FSC has begun to be used for elucidating various phenomena. In this paper, some examples of the utilization of thermal analysis, such as DSC,TMDSC, and FSC, in the R&D of polymer materials are described, focusing on the fusion phenomenon of polymer crystals, the structural analysis of polymer hydrogels, and, finally, the analysis of amorphous structures.
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  • Application of Thermal Analysis in the Development of Novel Cosmetic Formulations
    Toru Okamoto
    2019 Volume 46 Issue 4 Pages 163-168
    Published: October 15, 2019
    Released on J-STAGE: November 20, 2022
    DOIhttps://doi.org/10.11311/jscta.46.4_163
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    In this article, the application of thermal analysis in the development of skin care cosmetics was explained based on three cases. The α-gel formed by fatty alcohols and surfactants is deeply involved in the physico-chemical properties and usability of cosmetic creams. The formation and physical properties of α-gel were verified by thermal analysis. By reducing the emulsion particle size in this cream formulation, the cream was transferred to a low viscosity water-like formulation. In order to keep this formulation stable, it was necessary to reduce the particle size of the emulsion until all the α-gel could be adsorbed from the aqueous phase to the emulsion interface. To prove this condition, quantitative analysis of the transition of α-gel to the interface by thermal analysis was useful. The extra-large size emulsion was stabilized by precipitation of fatty alcohol crystals around the emulsion particles. This structure was derived by finding the difference between the surface and internal state of the particles by thermal analysis. Thermal analysis clarified the physical properties and phenomena of the formulation and provided scientific support to establish it as a formulation technology in the development of a novel formulation.
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  • Elucidation of Cold Crystallization of Schiff-base Nickel(II) Complexes
    Katsunori Iwase
    2019 Volume 46 Issue 4 Pages 169-174
    Published: October 15, 2019
    Released on J-STAGE: November 20, 2022
    DOIhttps://doi.org/10.11311/jscta.46.4_169
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    Cold crystallization is an exothermic, monotropic transition that occurs at a temperature below the sample's normal melting point during the heating process. It is thus possible to utilize the phenomenon so that a heat storage material can eliminate the time lag between heat supply and demand. In an attempt to examine some metal complexes as potential candidates for heat storage materials, Schiff-base–Ni complexes bearing tolyl (OT, MT, and PT) and isopropyl (IP) groups at the N-terminal were prepared and investigated by thermal analysis, X-ray diffractometry, FTIR-DSC measurement, and DFT calculation. The behavior of supercooling and cold crystallization observed for these four compounds led to the following two basic guidelines for designing materials to exhibit the desired heat storage property: (1) the molecular flexibility should be enhanced in order to increase the activated energy for crystallization; (2) the liquid state consists of a mixture of two (or more) conformational isomers. These guidelines are useful to prevent the molecules from crystallization during cooling, and to afford a glassy state via deep supercooling, resulting in cold crystallization in the subsequent heating process.
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  • Study of Liquid-Liquid Transition of a Molecular Liquid by Fast Differential Scanning Calorimetry
    Mika Kobayashi, Hajime Tanaka
    2019 Volume 46 Issue 4 Pages 175-181
    Published: October 15, 2019
    Released on J-STAGE: November 20, 2022
    DOIhttps://doi.org/10.11311/jscta.46.4_175
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    Liquid has been widely believed to have a random homogeneous structure, but recent studies have shown that liquid can have local structural order. This local structural ordering allows even a single-component substance to have more than two liquid states. Liquid-liquid phase transition (LLT) between different liquid states is of fundamental importance to understand the physical nature of liquid, and thus has attracted much attention. A molecular liquid, triphenyl phosphite (TPP), has been known to have two distinct amorphous states. However, the nature of the newly found apparently amorphous state called “glacial phase” has been a matter of debate for a long time, primarily because it usually contains nanocrystals. Thus, some researchers thought that the glacial phase is just an exotic solid state formed by nanocrystals. To solve this controversy, we applied a fast differential scanning calorimetry (DSC), whose scan rate is faster by 104 times than conventional DSC, and succeeded to suppress nanocrystal formation and observe the transformation process between two pure liquid states including its reversible process. Our study unambiguously shows the first-order nature of the transition and provides firm evidence that the transition is LLT.
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  • Analysis of Temperature Waveform Measured by Temperature-Modulated Calorimetry
    Hidehiko Honda
    2019 Volume 46 Issue 4 Pages 182-187
    Published: October 15, 2019
    Released on J-STAGE: November 20, 2022
    DOIhttps://doi.org/10.11311/jscta.46.4_182
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    In this study, an analytical method for the temperature waveform measured by temperature-modulated calorimetry is described, and the measurement results of n-hexatriacontane are given as an example. The boundary conditions between the sample and surroundings are investigated by comparing the temperature waveforms obtained when the shape of the sample was altered. In this measurement, a cylindrical sample cell with a radius of 3.0 mm was used. It was found that when the thickness of the sample exceeded 2.0 mm, a portion of the heat flowing out of the sample did not affect the temperature waveform. The amount of heat that flowed out was difficult to measure directly. By analyzing the temperature waveform, we could identify measurement conditions that can ignore physical quantities difficult to evaluate such as heat flow. In other words, this waveform analysis improves the accuracy of the analysis of physical property values. As another example, we also describe an analytical method of the waveforms measured in the phase transition temperature range. The characteristic waveforms were measured because the value of dynamic specific heat changed significantly in the phase transition temperature range. The characteristic waveforms measured in the temperature range are shown as examples.
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  • In situ Electrochemical Hole Doping and Magnetic Response of Prussian Blue Thin Film
    Mariko Noguchi
    2019 Volume 46 Issue 4 Pages 188-194
    Published: October 15, 2019
    Released on J-STAGE: November 20, 2022
    DOIhttps://doi.org/10.11311/jscta.46.4_188
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    Recently the electrical switching of magnetization and magnetic properties have been attempted by many researchers for the application to practical devices. This review introduces a significant magnetic response of Prussian Blue (PB) thin film incorporated in an ionic-liquid electrolysis cell by applying a DC bias voltage. Electrochemical hole doping into the PB film oxidized FeII to FeIII ions in the film, providing quasi-reversible electrochromic behaviour. We performed magnetic measurements of the electrolysis cell under a DC bias on an SQUID magnetometer. The switching of the film from a paramagnet to a ferrimagnet with a magnetic response at low temperatures and an in situ enhancement of magnetization of the film at 300 K were demonstrated.
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  • Chemical Thermodynamics for Analytical Chemist
    Ryo Kanzaki
    2019 Volume 46 Issue 4 Pages 195-201
    Published: October 15, 2019
    Released on J-STAGE: November 20, 2022
    DOIhttps://doi.org/10.11311/jscta.46.4_195
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    One of the fundamental roles of analytical chemistry is to provide the information of chemical species distributing in solutions, where chemical equilibria of acid dissociation, dissolving of salts, complex formation, electrode reaction, etc., are considered. This extensively owes to chemical thermodynamics, however, the relationship is rarely taught in detail in the class of physical chemistry nor analytical chemistry. It will be a great loss in both fields. In this article, with beginning from the usual equilibria in analytical chemistry, its groundwork of chemical thermodynamics will be explained. First, chemical potential is introduced as the determining factor of equilibrium constant, then Gibbs energy is defined. Although this is inverted from the ordinary way of instruction, possibly more convenient for the field of analytical chemistry. Then, activity coefficient and the standard state are explained, followed by the derivation of chemical potential from the work for changing concentration of solute in solution for clarifying its physical meaning. Turning to the solvent, the solvent transfer is considered by both transfer Gibbs energy and transfer activity coefficient. Finally, electrochemical potential is outlined. They are described within the word of analytical chemistry. Hopefully, this article will help establishing the energy-based perspective on the chemical equilibria in solutions.
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  • STEM-based Thermal Analytical Microscopy by Using Nanothermocouple
    Naoyuki Kawamoto, Yohei Kakefuda, Isamu Yamada, Masanori Mitome, Yoshi ...
    2019 Volume 46 Issue 4 Pages 202-209
    Published: October 15, 2019
    Released on J-STAGE: November 20, 2022
    DOIhttps://doi.org/10.11311/jscta.46.4_202
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    We developed a scanning transmission electron microscopy (STEM)-based thermal analytical microscopy (STAM) technique through performing a local temperature measurement using an assembled nanothermocouple under scanning of a focused electron beam over the samples in the STEM mode. Herein, we report on the principle of nanoscale thermal conductivity using STAM and its application for heat sink composite as model specimen. STAM allows for high thermal and spatial resolutions during nanoscale thermal flow propagation within a heatsink composite. Comprehensive thermal tests combined with structural, mechanical, electrical, magnetic, and optoelectronic characterizations by TEM may become one of the most powerful tools for understanding complex heat transfer phenomena in advanced nanoscale materials at nanoscale.
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