Netsu Sokutei
Online ISSN : 1884-1899
Print ISSN : 0386-2615
ISSN-L : 0386-2615
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Volume 48, Issue 3
Displaying 1-8 of 8 articles from this issue
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Article
  • Development of Quasi-Conduction Type of Calorimeter for Solution and Applications to Systems of Aqueous Solutions
    Hideo Ogawa, Yuichi Sugawara, Kenichi Kokubu, Kyosuke Kozuka, Natsuki ...
    2021 Volume 48 Issue 3 Pages 93-99
    Published: July 25, 2021
    Released on J-STAGE: June 20, 2022
    DOIhttps://doi.org/10.11311/jscta.48.3_93
    JOURNAL FREE ACCESS
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    A simple design of quasi-conduction type of calorimeter has been developed and constructed using cheap parts and commercially available equipment to measure enthalpy of dissolution, titration or mixing of liquid easily. Heat change of the calorimeter could be calculated from detected temperature change on mixing of liquids by Wheatstone bridge circuit with thermistor temperature sensor. Resolution and reproducibility were estimated to be less than 0.03 J in observed heat and 0.6 %, respectively, from linearity test using the calibration heater. Result of enthalpy of dissolution of 1-propanol in water at infinite dilution was 10.52 kJ mol−1 , which agreed with IUPAC standard value within 3.5 %. To demonstrate the applicability to education, academic study and industrial development, the apparatus was used in three types of measurements. From the study of enthalpy of dissolution of ethanol in aqueous salt solution, weakened solvation enthalpy of ethanol in water was observed by adding CaCl2 rather than adding MgCl2. In application of titration measurement for neutralization of acid with aqueous NaOH base, oxalic acid and phosphoric acid show different values for equivalent neutralization heat at each different dissociation step of ionization equilibrium. In the measurement of enthalpy of mixing, endothermic heat was detected for mixing of LiCl + NaCl aqueous solutions, regardless of exothermic heat for LiCl + all the other salts.
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Review
  • Physics and Materials Science Studies on Spin Caloritronics Revealed by Lock-in Thermal Measurements
    Ken-ichi Uchida, Ryo Iguchi
    2021 Volume 48 Issue 3 Pages 100-107
    Published: July 25, 2021
    Released on J-STAGE: June 20, 2022
    DOIhttps://doi.org/10.11311/jscta.48.3_100
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    Spin caloritronics is the fusion research field based on the combination of spintronics, thermoelectrics, and thermal energy engineering, where the interplay between spin, charge, and heat currents has been extensively investigated. Recently, we have clarified detailed behaviors of various magneto-thermoelectric and thermo-spin effects and demonstrated novel thermal control functionalities realized by spin caloritronics by means of the active heat detection techniques called the lock-in thermography and lock-in thermoreflectance methods. In this article, we explain the measurement principles and features of these lock-in heat detection techniques, and review recent developments in spin caloritronics. These techniques are useful not only for elucidating physics of spin caloritronics but also for finding good magneto-thermoelectric and thermo-spin conversion materials.
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  • Lipid Nanodisc Technology and Its Application to Thermal Analysis
    Kazuma Yasuhara
    2021 Volume 48 Issue 3 Pages 108-113
    Published: July 25, 2021
    Released on J-STAGE: June 20, 2022
    DOIhttps://doi.org/10.11311/jscta.48.3_108
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    Biomembranes play important roles not only as a cross-wall to compartmentalize the cytoplasmic components, but also as an interface for various biological functions such as material transport, signal transduction, and energy production. The interplay of phospholipid bilayers and membrane proteins in the biomembranes contributes to realizing sophisticated cellular functions. To investigate the physicochemical nature of lipid bilayers and the mechanism of membrane-related function, various model membrane systems have been developed so far. Lipid nanodiscs, which are aqueous assemblies encompassing the smallest lipid bilayers inside, have attracted much attention in recent years. Compared to conventional vesicles, lipid nanodiscs have several advantages such as uniform small size, dispersion stability in aqueous solution, and easy preparation. Taking advantage of these features, lipid nanodiscs have been applied to the analysis of membrane-associating molecules including membrane proteins. Previously, several preparation methods of lipid nanodisc have been developed, including bicelles formed by the mixture of phospholipids with different hydrophobic chain lengths, complexation of lipid membranes with membrane scaffold proteins, and fragmentation of membranes by amphiphilic polymers. In this paper, we review these strategies for nanodisc formation and discuss the physicochemical properties of nanodiscs based on the analysis of differential scanning calorimetry (DSC).
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  • Heat Capacity of Polymers
    Kazuhiko Ishikiriyama
    2021 Volume 48 Issue 3 Pages 114-121
    Published: 2021
    Released on J-STAGE: June 20, 2022
    DOIhttps://doi.org/10.11311/jscta.48.3_114
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    The analysis procedure of heat capacity for polymers using DSC, as well as crucial tips for the measurement procedure and the advantages of analyzing DSC traces using heat capacity, are summarized. Heat capacities of polymers can be calculated based on group vibrations and skeletal vibrations linked to the Tarasov function, which has been established by B. Wunderlich et al. as the ATHAS (Advanced Thermal Analysis System) scheme. The ATHAS data bank contains equilibrium information on heat capacities and transition parameters for over 200 polymers and polymer-related materials. The ATHAS schemes for polydioxanone, polytetrafluoroethylene, and polyethylene terephthalate are described. The method for accurately determining the crystallinity of polymer is explained on the basis of the ATHAS data bank. The availability of heat capacity proved to be of great importance for the analysis of metastable states such as rigid amorphous and conformational disordered crystal states of polymers.
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  • Phase Transition and Morphology of Micro-Crystal and Thin Film
    Masayuki Iwasa, Hirohisa Yoshida
    2021 Volume 48 Issue 3 Pages 122-128
    Published: July 25, 2021
    Released on J-STAGE: June 20, 2022
    DOIhttps://doi.org/10.11311/jscta.48.3_122
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    The effects of sample mass, interface and surface on the phase transitions and morphology were investigated by DSC and SPM for n-alkyl alcohols and poly(ethylene oxide), PEO. The solid phase transition and the melting temperatures of n-alkyl alcohol shifted to lower temperature with decreasing the mass. Both even and odd carbon number of alcohols classified into 3 groups by the mass dependence of melting and solid phase transition temperatures, which was induced by the crystal morphologies, such as the flat plate, the block on plate and the block. The sample surface influenced the solid phase transition and disturbed to transfer to β or γ phase from α phase with the mass below 30 µg corresponding to 60 layers of bimolecular alcohols. The interface influenced the crystallization mechanism and disturbed the crystallization within 10 layers of bimolecular alcohols. The melting temperature depression was observed with the decrease of sample mass, which was described very well by Thomson-Gibbs equation. The lamellar thickness estimated by T-G equation of PEO with sample mass less than 30 µg was confirmed by SPM observation.
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  • Prediction of Heat Capacity of Main Chain Polymer Based on Molecular Vibration Analysis
    Marika Yokota, Itaru Tsukushi
    2021 Volume 48 Issue 3 Pages 129-133
    Published: July 25, 2021
    Released on J-STAGE: June 20, 2022
    DOIhttps://doi.org/10.11311/jscta.48.3_129
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    This study predicts the absolute values of heat capacities from the molecular formula per monomer for main-chain- type polymers below the glass transition temperature. The frequencies of the skeletal and group-vibration modes are calculated using the Tarasov and Einstein equations, respectively, and differences between the heat-capacities at constant pressure and constant volume are used to correct the predicted heat capacity. The contributions of skeletal vibrations to the heat capacity can be expressed by one- and three-dimensional Tarasov equations, and the contribution of group vibrations can be determined by summing the group-vibration heat capacities for functional groups and atoms constituting the monomer as obtained from the Einstein equation. The absolute value of the heat capacity is predicted from this combination of equations. The heat capacities of poly(1,4-butylene adipate) are predicted within an error range of ±3.0 % from 80 to 200 K.
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Help Keywords
Applied Research of Thermal Analysis
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