NetsuSokutei 31 (1), 2-5 (2004)
Quantitative Differential Thermal Analysis of Dehydration of Brucite under
High Pressure
Hiroshi Fukui, Tomoo Katsura, and Osamu Ohtaka
Dehydration of brucite was measured by means of high-pressure differential
thermal analysis (HP-DTA). The enthalpy of the dehydration was derived
as a function of temperature and pressure from thermodynamic quantities
of brucite, periclase, and H2O fluid. The dehydration of brucite is likely
to be used to quantify an HP-DTA system up to 6 GPa. The system calibration
factor was determined to be 1.2。゜10。ン3 J K。ン1 s。ン1.
Osaka University
NetsuSokutei 31 (1), 6-13 (2004)
Water; Dynamics and Reactions
Shinji Saito, Masakazu Matsumoto, and Iwao Ohmine
Various aspects of Water Dynamics are discussed; (1) Fluctuation and
relaxation in hydrogen bond network rearrangement and their observation,
(2) Mechanism of water freezing, and (3) Proton transfer in liquid water
and ice. Liquid water yields the intermittently collective motions
accompanied with large fluctuations. Various relaxation processes
associated with these collective motions in liquid water yield so-called
1/f spectra. We present the result of our analysis on a method, called
2-dimensional Raman/IR spectroscopy. This method will be able to deal with
the mechanism of these intermittent collective motions. Upon cooling,
water freezes into ice. This process is a most familiar phase-transition,
occurring in many places in nature, but has never been successfully simulated
by a computer simulation. We report the first successful simulation for
the pure water freezing process, which gives a molecular level picture
of, particularly, how an initial nucleus is created and grows.
The proton transfer is a most basic reaction in chemistry and biochemistry.
It is found that the mechanism of the proton transport in ice is completely
different from that in liquid water. The repulsion from fourth coordinated
water makes the facile proton transfer possible. The long range solvation
is essential for the smooth transport of the proton in ice.
Nagoya University
NetsuSokutei 31 (1), 14-22 (2004)
The Structure and Properties of Supercritical Water
Masaru Nakahara
First we explain the importance of the investigation on the structure
and properties of supercritical water in relation to the chemical evolution
and the environmental and energy issues of the 21st century. Molecular
interpretations are given to the temperature dependence of the density,
dielectric constant, and viscosity, hydrogen-bonding structure, and dynamics
of supercritical water. The three-dimensional network structure, characteristic
of ambient water, is broken down in hot expanded water at temperatures
higher than 。チ200。� and densities lower than 。チ0.9 g cm。ン3. The number
of hydrogen bonds per molecule has been determined by the NMR method combined
with computer simulation; it decreases from 。チ4 for ambient water to 1-2
for supercritical water at 400。� and the critical density (。チ0.32 g cm。ン3).
The NMR rotational correlation time (t2R) for supercritical water at the
medium densities is in the range of 50-70 fs, two orders of magnitude smaller
than the ambient value (2 ps). Supercritical water is shown to be an alternative
to hazardous organic solvents; there are being found new hydrothermal organic
reactions without catalyst for the development of green chemistry.
Kyoto University
NetsuSokutei 31 (1), 23-28 (2004)
Polyamorphism in Water and the Second Critical Point Hypothesis
Osamu Mishima
Liquid water shows the eccentric properties at low temperatures such as
the maximum density at 4。�. The amorphous solid form of water also shows
a peculiar phenomenon known as polyamorphism. Poole et al. has proposed
the second-critical-point hypothesis of water and explained these properties.
The experimental and theoretical studies support the hypothesis, but further
proofs are required.
NIMS
NetsuSokutei 31 (1), 29-36 (2004)
Experimental Charge Density Distribution by the Maximum Entropy Method
Makoto Sakata, Eiji Nishibori, and Masaki Takata
The accurate charge density studies by the Maximum Entropy Method
(MEM) utilizing X-ray diffraction is outlined with some examples. The basic
concept of the method is stated in some details. In addition, some experimental
charge densities are given to demonstrate the usefulness of the method,
such as endohedral metallofullerenes, metal hydride and intermetallic compounds.
In La2@C80 metallofullerene case, the extraordinary charge density distribution
is revealed, that is two La atoms form pentagonal dodecahedron charge density
due to the hopping motion inside fullerene cage. In MgH2 metal hydride
case, charge density peaks of hydrogen atoms are clearly found in MEM charge
density map, whereas no such charge density peaks are found in direct Fourier
charge density map.
Nagoya University
Netsu Sokutei 31 (2), 62-68 (2004)
Excess Enthalpies of Some Nitrile Compounds 。ワ Methyl Methylthiomethyl
Sulfoxide or 。ワ Dimethyl Sulfoxide at 298.15 K
Takayoshi Kimura, Takanori Matsushita, Kenzi Suzuki, and Sadao Takagi
Excess enthalpies of binary mixtures between each of acetonitrile, propionitrile,
butyronitrile, pentanenitrile and benzonitrile。ワmethyl methylthiomethyl
sulfoxide (MMTSO) and。ワdimethyl sulfoxide (DMSO) have been determined at
298.15 K. All mixtures showed positive enthalpy change over the whole range
of mole fractions except acetonitrile + DMSO over 0.95 in mole fraction
of DMSO.
Partial molar enthalpies of the mixtures of acetonitrile(1)。ワDMSO (2)
around 0.65 in mole fraction have maximum of HE1 and minimum of HE2. Linear
relations are obtained between limiting excess partial molar enthalpies
and (m12 m22)(r1。ワr2)。ン6 except the mixtures containing for benzonitrile.
However limiting excess partial molar enthalpies of the mixtures of aromoatic
compounds。ワMMTSO or。ワDMSO showed good relation with (a2m12。ワa1m22)(r1。ワr2)。ン6.
Kinki University
Netsu Sokutei 31 (2), 69-73 (2004)
Evaluation of Molecular State of Medicines by Differential Scanning Calorimetry
Yuichi Tozuka and Keiji Yamamoto
This review describes the evaluation of molecular state of medicines by
using differential scanning calorimetry (DSC). Thermal behavior of amorphous
clarithromycin obtained by grinding and spray drying were evaluated. In
DSC curves, both broad and sharp peaks for crystallization were observed
in 30 min ground sample, whereas spray-dried sample showed one broad peak
for crystallization. In order to study the physicochemical stability of
amorphous cefditoren pivoxil, glass transition accompanying enthalpy relaxation
was evaluated for the ground and spray-dried samples by means of modulated-temperature
DSC. Glass transition temperature (Tg) and relaxation enthalpy of the ground
sample of cefditoren pivoxil were changed by storage for definite intervals
at a temperature below Tg, while those of the spray-dried sample indicated
an almost constant value by storage. These results suggest that the ground
sample was less stable than the spray dried sample. The ground sample might
be stabilized by storage below Tg. Thermal behavior of salicylamide in
the mixtures with Folded Sheets Mesoporous Materials (FSM)-16 was investigated
by DSC. Three kinds of molecular states of salicylamide, i.e., crystalline
state, disordered crystalline state for which a broad endothermic peak
was observed at a lower temperature, and amorphous state for which no peak
on the DSC curves could be observed.
Chiba University
Netsu Sokutei 31 (2), 74-79 (2004)
Investigation of the structural Relaxation Process of Amorphous Formulation
by Isothermal Microcalorimetry
Kohsaku Kawakami
The use of isothermal microcalorimetry for analyzing structural relaxation
and recovery processes of amorphous materials is discussed. Unlike the
conventional DSC method, this new method enables to directly monitor the
relaxation process. Also featured in this article is its application for
investigating the recovery process, which has hardly been reported in literature.
The both processes were elucidated using Kohlrausch-Williams-Watts derivative,
although its application for the recovery process needs discussion. The
relaxation parameters obtained by this procedure agreed very well with
those from the DSC method. The advantages and disadvantages of this method
are summarized.
Shionogi & Co., Ltd.
Netsu Sokutei 31 (2), 80-86 (2004)
Application of Isothermal Microcalorimetry for
Stability Evaluation of Solid Dosage Form
Yasuo Yoshihashi, Yonemochi Etsuo, and Katsuhide Terada
This review demonstrated the possibility of application of isothermal microcalorimetry
(IMC) for stability evaluation of solid dosage form. Various kinetic equations
derived from the different reaction model in the solid state were applied
for the obtained data using isothermal microcalorimeter. Suitable decomposition
rate constant was successfully derived from the most appropriate kinetic
equation evaluated by curve fitting method. Experimental decomposition
rate constant of solid dosage form was determined by the time-consuming
conventional method, which took more than 6 months. The predicted values
were in good agreement with the experimental values. By using this method,
the stability of solid dosage form can be predicted by a simple operation
in a short time. Application of IMC would be useful for the screening test
for the drug stability.
Toho University
Netsu Sokutei 31 (2), 87-92 (2004)
Ice crystals and glassy water in frozen polymer gels
Norio Murase
To understand the mechanism of ice crystallization during rewarming observed
with a frozen crosslinked dextran gel of a certain density of crosslink,
DSC, Raman scattering and X ray diffraction-DSC simultaneous measurements
were conducted. It was found, as a result, that size of ice crystals as
well as freezing behavior depend on the density of crosslink of the gels.
By the study of two-dimensional X ray diffraction-DSC simultaneous measurements,
formation of small ice crystals was indicated with the gel where ice crystallization
during rewarming is observed. Presence of glassy water was also indicated
in the frozen state of the gel by the measurement of Raman scattering.
Then, it was clarified that ice crystallization in polymer gels is more
or less obstructed by the polymer network, and by its change at the time
of freezing. From these results together with the knowledge so far obtained,
a conceivable mechanism of ice crystallization during rewarming was discussed.
Tokyo Denki University
Netsu Sokutei 31 (3), 100-107 (2004)
Thermodynamic Investigation of Zn-Te Alloys by Calorimetry
Katsunori Yamaguchi
The heat contents of the ZnTe compound were measured by a drop calorimeter
in the temperature range from 750 to 1600 K. The enthalpy of fusion of
the ZnTe compound was determined as 51.1。゛0.3 kJ mol。ン1 at corresponding
melting point of 1573。゛3 K. The heat content and heat capacity equations
were derived by Shomate function for the solid compound. The enthalpy of
formation of the ZnTe compound and the integral enthalpy of mixing for
the liquid Zn-Te system were measured by direct reaction calorimetry at
800, 1173 and 1373 K using a high temperature twin calorimeter. The enthalpy
of mixing of the liquid Zn-Te phase shows large negative values in the
neighborhood of the compound composition. This behavior dependent anomalies
is explained by a chemical short range order in liquid alloys. The obtained
thermodynamic data for the Zn-Te system was used to reassess the system
following CALPHAD standard. An associated solution model for the liquid
phase and standard Gibbs energy functions for the three solid phases (Zn,
ZnTe and Te) were used. The thermodynamic properties and phase diagram
calculated from the reassessed system agree well with the experimental
data.
Netsu Sokutei 31 (3), 108-116 (2004)
The Significance of Thermal Analysis in the Development of Teaching Materials
for Chemistry Education
- As Exemplified by the Precipitation Reactions of Zinc Salts and their
Thermal Decompositions -
Haruhiko Tanaka, Yoshinobu Matsuda, Nobuyoshi Koga, and Yoshihiro Furukawa
Thermoanalytical studies of reactions involving basic zinc salts
were made as an example of application of thermal analysis to the fundamental
research on developing teaching materials for chemistry education. The
studies were complemented by pH titrimetry, thermometric titrimetry, chemical
analysis, IR spectrometry, and X-ray diffractometry. On the basis of the
results, the possibility was suggested that some investigative teaching
materials are developed by introducing the precipitation reactions and
thermal decomposition of the basic zinc salts into chemistry courses at
a secondary education level. It was proposed that the thermoanalytical
measurements for the basic zinc salts applied in the present study are
also utilized successfully as teaching materials for educating thermal
analysis at universities and colleges.
Netsu Sokutei 31 (3), 117-124 (2004)
Evaluation of the Growth Activity of Microbial Colonies on Solid Medium
using Calorimetry
Kunimasa Koga
In many cases, microbes exist on solid phase. Microbes on solid
phase multiply as colonial growth. It is known that the growth on
solid phase is different from the growth in liquid state. Comparing
with microbes in liquid state, microbes on solid phase are hard to take
nutrients. And the environment of microbes varies from place to place
in the colony and affects the metabolism of microbes.
Information of colonial growth of microbes on solid phase is required
for prevention of putrefaction of solid food, utilization of soil microbes
or investigation of a infection mechanism of pathogenic bacteria to an
organism.
However, the information regarding colonial growth of microbes on solid
phase is not enough compared with that of microbes in liquid state by the
reason of the absence of suitable and quantitative methods of estimating
the colonial growth curve.
In this article, microbial calorimetry is introduced to be the method
suitable for non-destructive measurement of microbial colonial growth on
solid phase. Changes in the metabolic heats of colonial growth with time
(the growth thermogram) are obtained with good reproducibility. The
actual heat evolution curves (f(t) curves) obtained from the thermograms
of growing colonies give good agreement with the changes in viable cell
numbers in colonies under the same conditions. Using microbial calorimetry,
the colonial growth of microbes can be evaluated quantitatively. And still,
the method is useful for evaluation of the complicated phenomenon by microbes
such as putrefaction, and development of novel natural substances which
suppress the colonial growth microbes.
Netsu Sokutei 31 (3), 125-132(2004)
Non-isothermal Kinetics (1) Single Elementary Process
Takeo Ozawa
Fundamental relations are derived for a single elementary process by using
concepts of "generalized time" and "generalized rate". These concepts are
useful for describing reactions in which only a single elementary process
is involved, and by using these useful relations iso-conversion methods
for kinetic analysis, both of integral methods and a derivative method,
are derived and explained with some illustrations. The methods for kinetic
analysis and other descriptions in this article are also applicable to
physical changes of a single elementary process, such as diffusion and
thermal stimulated currents.
Netsu Sokutei 31 (3), 133-145(2004)
Proton Cloud
- The Wave Nature of Proton and Its Consequences in the Properties of Crystals
-
Takasuke Matsuo
This paper reviews structure and properties of crystals related
to quantum mechanics of nuclear motion. The basic quantum theory of the
harmonic oscillator and free rotor formed by atoms in molecules is briefly
reviewed. It is extended to include tunnel states as explicit indication
of the wave-like property of the nucleus. The term proton cloud is introduced
to describe the delocalized proton. Deuteration-induced phase transitions
in bromohydroxyphenalenone is presented as evidence for the quantum nature
of the nuclear motion. Direct observation of the tunnel level by far infrared
spectroscopy is described along with the potential energy curve for the
proton derived from the spectroscopic data.
Isotope-dependent properties are further reviewed for deuteration induced
phase transitions in tri-alkali hydrogen disulfates and similar diselenates
studied by calorimetry and neutron diffraction. Neutron diffraction at
low temperature shows a delocalized proton in ground state of these crystals.
In chromous acid an even stronger isotope effect occurs and has been discussed
in terms of the crystal structure of this particular compound. Rotational
tunneling of ammonium ions and its consequences in the phase behavior and
structure are then discussed for diammonium hexachloroplatinate and isomorphous
cubic crystals. Neutron diffraction combined with the low temperature heat
capacity has revealed that the hydrogen nuclei in these crystals are delocalized
in tori of 0.8 angstrom in diameter which surround tetrahedrally the nitrogen
atom at the center of the ammonium ion. Finally, the relation of the wave-like
properties of nuclear motion to chemical reaction and proton polarizability
is discussed.
Netsu Sokutei 31 (3), 146-150(2004)
Historical Background of Standard State Pressure
Yatsuhisa Nagano
The history from the recognition of atmospheric pressure to the thermodynamic
standard state pressure (SSP) is reviewed. Originally, the SSP was defined
to be 101.325 kPa, one atmosphere in terms of a conventional unit, which
was based on the normal atmosphere. However, IUPAC recommended 100 kPa
as a new SSP in 1981. The normal atmosphere had not just been a standard
(prototype) of pressure unit, but a knowledge relating to the recognition
of atmospheric pressure and the normal boiling points of chemical substances.
This is the reason why the IUPAC recommendation on the SSP has not completely
prevailed even in chemistry.
Netsu Sokutei 31 (4), 164-171
(2004)
Thermoelectric effects in transition-metal oxides- Thermodynamics in strongly
correlated electrons -
Ichiro Terasaki
A strongly correlated electron system is a system that the Coulomb repulsion
between electrons is too strong to hold the one-electron picture in solids.
As a result, it can exhibit superior functions to conventional solids in
which one-electron picture (band picture) is valid. Recently, thermoelectricity
due to strong correlation has attracted a keen interest, and some transition-metal
oxides, which are typical examples of strongly correlated electron system,
can be a good thermoelectric material. In this article we will review the
thermoelectric and thermodynamic properties of the transition-metal oxides
through thermopower measurement.
Waseda University
Netsu Sokutei 31 (4), 172-178
(2004)
Investigation of Phase Relationship of Perovskite-related Oxide Materials
by Thermal Analyses
Takuya Hashimoto
New phases have been discovered in high functional perovskite-type oxides
with various thermal analyses and X-ray diffraction under specific conditions
such as high temperatures and high pressures. The second order phase transition
was observed in Ba2In2O5 at 1070。� by dilatometry and quantitative DTA.
It was revealed that distortion from the ideal cubic perovskite structure
is the smallest in the phase found at higher temperatures than 1070。� and
that this phase has the highest potential as an oxide-ion conductor among
three phases in Ba2In2O5. In addition to the three phases in BaBiO3 already
discovered by neutron diffraction measurement so far, another phase has
been observed by dilatometry and quantitative DTA in temperature range
520~620。�. The X-ray diffraction peaks indicating existence of superstructure
was observed in diffraction pattern of BaBiO3 at 600。�. Variations of enthalpy,
DH, and volume, DV, were estimated by DSC and high-temperature X-ray diffraction,
respectively. Combining Clapeyron formula, positive DH and negative DV,
phase transition under high pressure at room temperature was deduced and
confirmed by X-ray diffraction at high pressures.
Nihon University
Netsu Sokutei 31 (4), 179-185
(2004)
Stability Prediction of Drug Substances using Thermal Analysis
Youichi Ueda, Masahiko Okamoto, Yasutaka Ohgami, and Kiyoshi Nakai
A stability test is one of the tests which are required the longest time
in a development of a drug. For quick release of new drugs to the market,
it is indispensable to estimate stability speedily from exact information
in preliminary stability tests, and to minimize idle time at an early developmental
stage. However, it is technically difficult to predict exactly in a short
time before a stability test, what decomposition will occur.
We developed a new stability prediction method using thermal analysis
to solve the problem. This method is very speedy; it only takes two weeks
to predict stability of a drug substance in detail. The operations are
simple; mainly thermal analysis and liquid chromatography. The method is
performed by minimum 1 mg per measurement. And total amount of sample being
necessary to predict stability is approximately 20 mg. The sample quantity
is so little that the method can be used even at an early developmental
stage when production scale is small. Furthermore, the accuracy and the
precision of prediction using the method are equivalent to or better than
those of 6-month preliminary stability tests. This method is very widely
applicable to chemical materials including pharmaceutical raw materials,
pharmaceutical intermediates, agricultural chemicals, and pesticides.
Sumika Chemical Analytical Service Ltd.
Netsu Sokutei 31 (4), 186-193
(2004)
Effect of Hydration on the Volume and Compressibility of Protein Molecules
Kunihiko Gekko
This review is devoted to illustrate how the hydration of proteins is related
to their volume and compressibility. Partial volume and partial compressibility
are thermodynamic (macroscopic) quantities but they are uniquely sensitive
to the structures of proteins because the hydration and the atomic packing
(cavity) have counteractive effects on these parameters. Compressibility
data give important information on the flexibility of the native structure
and the conformation of denatured states. Viewing a protein from both the
temperature and pressure axes should lead to a new paradigm in protein
science.
Hiroshima University
Netsu Sokutei 31 (4), 194-199
(2004)
Non-isothermal Kinetics (2) Multiple Elementary Processes
Takeo Ozawa
The theme dealt with in this article is non-isothermal kinetics of various
processes in which multiple elementary processes are involved. Firstly
fundamental equation of non-isothermal nucleation and growth process is
derived and it is compared with isothermal fundamental equation.
From the fundamental equation, method of kinetic analysis of data by constant
rate heating or cooling is derived. Theoretical considerations are also
made for parallel competitive reactions and consecutive reactions. For
the former some simple relations useful to elucidate the process can be
derived, but for the latter such a simple useful relation cannot be found,
but a fundamental equation is derived for specific cases. Finally usefulness
of temperature oscillation for analyzing reversible processes is discussed
together with its application to a reaction of a single elementary process.
Netsu Sokutei 31 (5), 212-216
(2004)
Historical Review on Development of the Japan Society of Calorimetry and
Thermal Analysis
Takeo Ozawa
History of the Japan Society of Calorimetry and Thermal Analysis is described
since the first Japanese Calorimetry Conference in 1965. The society was
established in 1969, and since then various activities have been made.
They are the conferences, the journal, organization of international conferences,
joint meetings with the Japan Society of Thermophysical Properties and
miscellaneous activities such as publication, workshops, group activities
and short courses for beginners. Statistical data are also reviewed. Finally
further development of the society in the future is discussed.
Netsu Sokutei 31 (5), 217-226
(2004)
A View of Thermal Measurements in JSCTA
Hiroshi Suga
Developments of microcalorimeters for combustion, heat capacity, and solution
calorimetry that have been done in our Society over the past four decades
are surveyed. Unique experimental results obtained for several equilibrium
and nonequilibrium systems are reviewed in some details. Molecular
systems are the main of these topics, hoping that the description reflects
the development of other fields in our Society, including metals, inorganic
and organic substances, synthetic polymers, and biological materials. Some
remarks for further works based on personal experiences are given in this
article.
professor Emeritus, Osaka University
Netsu Sokutei 31 (5), 227-233
(2004)
Thermodynamic Investigations and Characterization of Some Alloys in
Ternary Pb-Au-Bi System
Dragana Zivkovic, Biserka Trumic, and Zivan Zivkovic
The results of thermodynamic investigations and characterization of some
alloys in ternary Pb-Au-Bi system are presented in this paper. Partial
and integral molar quantities were determined in the temperature range
of 873。チ973 K, based on the comparative thermodynamic analysis done experimentally
using Oelsen calorimetry and analytically using Redlich-Kister-Muggianu
model. Characterization of chosen lead-based ternary alloys were done using
DTA, XRD and SEM analysis.
University in Belgrade
Netsu Sokutei 31 (5), 234-240
(2004)
Ordered Structures in Mesoscopic Scale of Amphiphilic Block Copolymers
Hirohisa Yoshida
The nano-scale ordered structure and phase transitions of amphiphilic di-block
copolymers consisted of hydrophilic poly(ethylene oxide) and hydrophobic
poly(methacrylate) derivatives having azobenzene (AZO) moieties as ester
groups, p(EO)mpMA(AZ)n, were reviewed. Hexagonal-packed PEO cylinder structure,
caused by micro phase separation of amphiphilic di-block copolymers were
selectively formed in wide copolymer content and temperature ranges for
p(EO)mpMA(AZ)n. The order of hexagonal cylinder depended strongly on the
annealing temperature, however, slightly on copolymer content. The series
of p(EO)mpMA(AZ)n showed four endothermic transitions on heating. From
the simultaneous DSC-XRD measurements, four phase transitions were assigned,
in the order of the low to high temperatures, as the melting of PEO, the
melting of AZO moieties, the transition from smectic C to smectic A and
the isotropic transitions, respectively. AZO moieties acted as megenic
groups. The formation of hexagonal cylinder structure was expected as the
results of entropy loss casued by liquid crystalline formation. The director
orientation of the liquid crystalline state would be the key in producing
the single crystalline nano-scale ordered hexagonal cylinder structure.
Tokyo Metroporitan University
Netsu Sokutei 31 (5), 241-248
(2004)
DSC and TMA of High Polymers
Minoru Todoki
Fundamentals of apparatuses and analyses of DSC and TMA were described
for polymeric materials.
In apparatuses, measuring principles were explained firstly and secondly
the two confusing problems of DSC, i.e., why two types of DSC, heat-flux
DSC and power-compensation DSC, do still exist, and why their charts adopt
opposite direction for Y-axis were elucidated from their historical and
measuring aspects.
In analyses, enthalpy and volume-temperature relationships of low molecular
weight substance were reviewed and apparently unusual behaviors of polymers
were pointed out. Finally nanosize behavior of polymer crystals was emphasized
as the most important topic among them and their zero-entropy-production
melting was exemplified for nylon 6 fibers, comparing with their conventional
melting.