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Volume 19 (1992)
- Issue 4 Pages 151-
- Issue 3 Pages 103-
- Issue 2 Pages 57-
- Issue 1 Pages 2-
Volume 19, Issue 2
Displaying 1-6 of 6 articles from this issue
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Takeshi Matsuda, Naruhito Ueno, Mahiko Nagao1992 Volume 19 Issue 2 Pages 57-63
Published: April 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSEnergetic properties of γ-Fe2O3 surface were investigated by means of adsorption calorimetry. The heat of adsorption and isotherm of water vapor on γ-Fe2O3 surfaces were measured directly and simultaneously by use of an adsorption calorimeter. The surface of γ-Fe2O3 was found to be less active and relatively uniform in energy for water adsorption. It was suggested that there exist at least two types of cation sites, i. e., five-coordinated Fe3+ ions and three-coordinated Fe3+ ions, for water adsorption. The former sites can interact with water molecules to produce surface hydroxyl groups on which further water molecules are physisorbed, while the latter ones act only as physisorption sites for water under usual conditions. The heat treatment at a temperature higher than 250°C or the oxygen treatment at 200°C reduces the energetic homogeneity of the adsorption sites on γ-Fe2O3.View full abstractDownload PDF (1087K) -
Ryoichi Kinoshita, Yoshihiko Teramoto, Hirohisa Yoshida1992 Volume 19 Issue 2 Pages 64-69
Published: April 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSAnalysis for thermal decompotision using a combined system of thermogravimetry (TG) and Fourier-Transform infrared absorption spectroscopy (FT-IR) was described. Two kinds of engneering plastics; poly (ethylene terephthalate) (PET) and poly (butylene terephthalate) (PBT) were measured by TG/FT-IR. The evolved gases at various temperatures were identified by the library search of FT-IR spectra according to their residual values. The main evolved gases from PET were carbon-dioxide and benzoic acid, while those from PBT were terephthalic acid esters and benzoic acid esters at initial stage of decomposition. The specific gas profiles, which were measurements of the integrated IR absorbance in the spectra as a function of temperature, were compared with TG curves and DTG curves. Different decomposition mechanisms were suggested between PET and PBT at initial stage of thermal decomposition.View full abstractDownload PDF (799K) -
Takae Kawai, Seiji Ito, Kazuo Tsutsumi1992 Volume 19 Issue 2 Pages 70-75
Published: April 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe amount and the characteristics of silanol groups, which were formed by hydrothermal and acidic treatments of H-type faujasites, were investigated by in situ IR spectroscopy, thermogravimetry in vacuo and mesurements of immersional heats.
The amount of the silanol groups which formed “hydroxy nest” decreased with an increase in the evacuation temperature. The amount of the silanol groups on meso pore surface and outside the crystal, which did not form “hydroxy next”, was almost constant in the temperature range between 298 and 873K.
The influence of the formation of “hydroxy nest” on the polarity of zeolite surface was investigated by measurements of immersional heats into water and some organic liquids. The immersional heats of H-Y770 into polar liquids were almost constant irrespective of the difference in the amount of silanol groups of zeolites. Therefore, the silanol groups which formed “hydroxy nest” were linked each other by hydrogen bonds and became inactive to approaching molecules.View full abstractDownload PDF (776K) -
Gerd Olofsson1992 Volume 19 Issue 2 Pages 76-85
Published: April 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe use of modern high-precision solution calorimeters to study the association of amphiphiles in solution is discussed. Examples of studies made by the author and coworkers are given. The thermodynamic properties for micelle formation of poly (oxyethylene) alkyl ethers, CnEx, in water and formamide solutions are summarized. Studies of the association of sodium dodecylsulfate SDS in water and aqueous pentanol solutions made to test a thermodynamic model for the association of ionic amphiphiles are described.View full abstractDownload PDF (1293K) -
Junji Nii, Takashi Uchida, Masataka Wakihara1992 Volume 19 Issue 2 Pages 86-90
Published: April 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSA personal computer program to calculate the equilibrium compositions in systems mainly containing gaseous species, CEPP, is briefly introduced. The purpose of CEPP is high speed calculation by simple operation. To attain this purpose, the calculation was simplified through restricting the available systems.
The Si-H-Cl system was selected in order to show sample operations of CEPP.View full abstractDownload PDF (652K) -
S. Itoh1992 Volume 19 Issue 2 Pages 91-93
Published: April 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (332K)
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