Tetsuya DANNO | Otsuma Women's University (original) (raw)

Papers by Tetsuya DANNO

Polymer Journal, 2013

We analyzed control of the crystalline structure of poly(vinilydene fluoride) (PVDF) in a PVDF/po... more We analyzed control of the crystalline structure of poly(vinilydene fluoride) (PVDF) in a PVDF/poly(methylmethacrylate) (PMMA) blend by varying the polymer blend ratio (PVDF/PMMA ¼ 60/40, 70/30 and 80/20 wt%) and the heat-treatment temperature (160-210 1C) just after the polymer melt. We obtained PVDF (form I) limitedly by heat treatment at 185 and 190 1C after blending PVDF/PMMA 70/30 wt%. The samples produced under other conditions indicated PVDF (form II). Results of differential scanning calorimetry (DSC), polarized light micrography and light transmittance indicated that samples of PVDF/ PMMA 70/30 wt% heat-treated at 185 and 190 1C exhibited high compatibility between PVDF and PMMA, respectively. In contrast, PVDF (form II) samples obtained in other conditions indicated lower compatibility. We assumed that PVDF crystalline structure became the structure of the PVDF (form I) according to decrease of the crystallization rate by the highest compatibility between PVDF and PMMA. Pure PVDF crystallized very fast, so PVDF (form I) cannot be developed from pure PVDF by simply controlling the heat-treatment temperature.

X-ray photoelectron spectra (XPS) of carbyne-like carbon (CLC) film obtained by the polymer react... more X-ray photoelectron spectra (XPS) of carbyne-like carbon (CLC) film obtained by the polymer reaction route were measured and analysed. Dehydrohalogenation reaction was carried out effectively regardless of the starting precursors. Cls core-level spectrum of CLC film shows the anomalous lowest peak maxima at 282.6 eV compared with the different carbon materials. An advanced model of carbyne chains concerning the conjugation length distribution is needed to analyse the electronic structure based on the valence-band XPS.

For the large scale application of electroactive polymers solubility, melt processability and evi... more For the large scale application of electroactive polymers solubility, melt processability and evironmental stability are prerequisites. Poly(alkylthiophenes) have attracted considerable attention and represent a new class of conjugated polymers characterized by their suitable processabilities1–3 and by their interesting physical properties,e.g., the thermochromic phase transition due to the thermally induced inter-ring torsions of the polymer backbone.4–6 We report the spectroscopic properties, especially the optical absorption and the resonance Raman scattering, of oriented or unoriented poly(octylthiophene)(POT) in the neutral and doped states.

Journal of Polymer Science: Polymer Physics Edition, 1983

Sorption of iodine by bulk polyacetylene was studied under various 12 gas pressures at 25°C. The ... more Sorption of iodine by bulk polyacetylene was studied under various 12 gas pressures at 25°C. The sorption dynamics show that the penetration of iodine into P A is not Fickian and the diffusion coefficient increases with time of sorption. A discontinuous increase in the sorption isotherm is observed at PIP0 = 0.25 ( P i s the pressure of the Ip gas and Po is the saturation value at 25°C). It is due to iodine penetration into PA crystals, as evidenced by x-ray analysis. The distribution of iodine within crystals is apparently inhomogeneous: some unit cells are changed into "iodine-PA" cells, while others remain unchanged. The electrical conductivity depends not only on the amount of iodine but also on the 12 gas pressure under which sorption is carried out. At given iodine content, the conductivity of a sample doped under higher 12 pressure is greater than that of a sample doped under lower pressure.

NIPPON KAGAKU KAISHI, 1986

The 13th international winterschool on electronic properties of novel materials- science and technology of molecular nanostructures, 1999

Physical Review B, 1991

... VOLUME 43, NUMBER 6 Optical anisotropy and Raman scattering from highly oriented poly(octylth... more ... VOLUME 43, NUMBER 6 Optical anisotropy and Raman scattering from highly oriented poly(octylthiophene) films T. Danno,* J. Kurti, and H. Kuzmany Institutfur Festkorperphysik, Universitdt Wien and Ludwig Boltzmann Institutffir Festkorperphysik, Wien, Strudlhofgasse 4, ...

AIP Conference Proceedings, 2000

ABSTRACT Resonance Raman scattering from carbyne films obtained by dehydrocholorination of poly (... more ABSTRACT Resonance Raman scattering from carbyne films obtained by dehydrocholorination of poly (vinylidene chloride) was studied under various laser excitation energies at room temperature. Four dominant Raman lines at around 1150, 1290, 1530 and 2150 cm-1 were observed. Each line showed clear dispersion effect between 10 and 40 cm-1/eV. The scattering line at 1150 cm-1 showed a slightly shift of 5 cm-1 towards the higher wave number when the specimen was exposed to ambient atmosphere. The intensity ratio of line at 2150 cm-1, which was referred to as the polyyne structure, to the one at 1530 cm-1 referred as the polyene structure increased with increasing of the energy of exciting laser. The averaged number of the conjugated atoms consisting of the polyyne structure was estimated to be about 10 from the comparison of the calculation of Sigmag mode frequency. .

Journal of Applied Polymer Science, 1985

The dehydrochlorination of a syndiotacticityenriched poly(viny1 chloride) (s-PVC) gave polyene ma... more The dehydrochlorination of a syndiotacticityenriched poly(viny1 chloride) (s-PVC) gave polyene materials and the structure and properties of dehydrochlorinated specimens were studied. The results were compared with those obtained for polyene materials formed from a commercial poly(viny1 chloride) (c-PVC). The crystallinity of the s-PVC was higher than that of the c-PVC as revealed by the infrared analysis and X-ray diffraction studies. The dehydrochlorinated specimens from the s-PVC were crystalline to some extent while those from the c-PVC were amorphous. The molecular orientation in the original films was preserved in the dehydrochlorinated specimens. The polyene films from the s-PVC had larger conductivities and showed better doping properties as compared with those from the c-PVC. These results were explained in terms of the larger crystallinity and the increased structural regularity of the s-PVC as compared with those of the c-PVC.

Journal of Applied Polymer Science, 1984

EXPERIMENTAL Sample and Reagents. PVC films about 10 pm thick were cast from THF (1-3 wt %) solut... more EXPERIMENTAL Sample and Reagents. PVC films about 10 pm thick were cast from THF (1-3 wt %) solutions of a commercial PVC (m = 1100, Mitsubishi Kasei Co.). Strips 15 mm wide and 35 mm long were cut from the film, and some of them were drawn six times with a manually operated device. Dimethylformamide (DMF), cyclohexanone (CHN), tetrahydrofuran (THF), methyl ethyl ketone (MEK), and o-dichlorobenzene (ODB) were used as swelling solvents, and methanol (MeOH) was used as a nonsolvent. DBU

Carbon, 1998

The surface of single crystal RbC60 was characterised by means of X-ray photoelectron spectroscop... more The surface of single crystal RbC60 was characterised by means of X-ray photoelectron spectroscopy (XPS). The atomic ratio of Rb to C up to 15 Å depth proved to be about two or three times higher than the stoichiometry (160) from the composition analysis. The top surface was covered by the oxidized hydrocarbon material and was fast removed by short

Synthetic Metals, 1987

Characterization and electrical properties of undoped cis-polyacetylene and annealed polyacetylen... more Characterization and electrical properties of undoped cis-polyacetylene and annealed polyacetylene were studied by measuring the electrical conductivities, the rate of isomerization, the cis-trans content, wide angle X-ray diffraction (WAXD) and electron spin rescnanee(ESR). In cis-polyacetylene the electrical conductivity decrease with a decrease in the amount of residual catalysts. The electrical conductivity decrease with excess heating since the interchain cross--linking of the radicals was occurred, which also induced a decrease of crystallinity. The activation energy of cis-trans isomerization increased with an increase in the trans content. The crystal transition during the isomerization occurred following a certain amount of cis-trans isomerization in the polyacetylene chain. Two crystal structures were found in trans-polyacetylene. Secondary battery using polyacetylene as a cathode was also studied. The charge and discharge capability was improved by the decrease of residual catalyst.