Kazuo Sasazawa

PbTiO3 Based Pyroelectric Ceramics Modified with Stannate Compounds

The properties of PbCa(Cu, Nb)TiO3–NiSnO3 based pyroelectric ceramics were investigated. Microstructures were examined by a X-ray microanalysis. The pyroelectric ceramics were consisted of three individual of PbCa(Cu, Nb)TiO3 phase NiSnO3–NiTiO3 compound phase and SnO2 rich phase in a ceramic composition. Pyroelectric properties of the ceramics were Fv of 8.5×10-11 C cm/J and Curie point of 272°. By an addition of NiSnO3 to Pb0.7Ca0.3(Cu1/3Nb2/3)0.05Ti0.95O3, Fv were up to the high value with an increase of P(P=5.8×10-8 C/cm2°C) and a decrease of es(es=220).

SYNTHESIS AND APPLICATIONS OF NOVEL FLUOROALKYL END-CAPPED OLIGOMERS CONTAINING 3,5-DIMETHYL-4-HYDROXYBENZYL AND 3-(2H-BENZOTRIAZOL-2-yl)-4-HYDROXYPHENYL SEGMENTS

New fluoroalkyl end-capped co-oligomers containing 3,5-dimethyl-4-hydroxybenzyl segments [RF‒(DMHB)x‒(DMAA)y–RF] were prepared by the reactions of fluoroalkanoyl peroxides with N-(3,5-dimethyl-4-hydroxybenzyl)methacrylamide [DMHB] and N,N-dimethylacrylamide (DMAA). Similarly, fluoroalkyl end-capped homo- and co-oligomers containing 3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl segments [RF–(BTRI)x–(Co–M)y–RF] were prepared by the reactions of fluoroalkanoyl peroxides with 2-[3–(2H‒benzotriazol–2–yl)–4–hydroxyphenyl]ethyl methacrylate [BTRI] and co-monomers [Co–M] such as acrylic acid (ACA), DMAA, and acryloylmorpholine (ACMO). The fluoroalkyl end-capped DMHB and BTRI co-oligomers thus obtained were soluble not only in water but also in common organic solvents. In addition, these fluorinated co-oligomers were able to reduce the surface tension of 0.1 N NaOH solutions quite effectively to around 20 mN/mlevels, although the corresponding non-fluorinated co-oligomers were not effective in reducing the surface tension of 0.1 N NaOH solutions. A modified polystyrene film surface treated with these fluoroalkyl end-capped DMHB and BTRI co-oligomers was found to exhibit a good oleophobicity imparted by fluorine with an excellent hydrophilicity. XPS analyses showed that end-capped fluoroalkyl groups in RF-(BTRI)n-RF homo-oligomer were arranged regularly above the modified polystyrene surface. Of particular interest, it was demonstrated that the self-assembled molecular aggregates formed by RF-(DMHB)x-(DMAA)y-RF co-oligomers could interact strongly with 7,7,8,8-tetracyanoquinodimethane (TCNQ) as a guest molecule to form a host–guest intermolecular complex, though such a host–guest interaction was not observed in the corresponding non-fluorinated DMHB co-oligomer.

Coloring-decoloring behavior of amphiphilic fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide--acryloylmorpholine cooligomer/fluorescein nanocomposites in protic and aprotic solvents.

Amphiphilic fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide-acryloylmorpholine cooligomer/fluorescein nanocomposites afforded brilliant yellow-colored solutions in not only protic solvents such as methanol and ethanol but also protic-like solvents such as dichloromethane and 1,2-dichloroethane, respectively. However, the corresponding non-fluorinated cooligomer/fluorescein composites and parent fluorescein gave the colorless solutions under similar conditions. On the other hand, unexpectedly, such brilliant yellow-colored solutions provided by these fluorinated nanocomposites completely disappeared in aprotic solvents such as N,N-dimethylformamide, dimethyl sulfoxide, and tetrahydrofuran. Thus, these fluorinated fluorescein nanocomposites can exhibit a coloring-decoloring behavior through solvatochromic response.

Properties of a ceramic capacitor composed of Zn-Cu electrodes

Abstract Zn-Cu electrodes were composed on both surfaces of ceramic capacitors and the properties were investigated. The electrical properties of a BaTiO3-based ceramic capacitor (Y5V) with a Zn-Cu electrodes were equal or excellent to the same ceramic capacitors with silver electrodes. An oxidation ratio of the fired Zn electrodes was examined by chemical analysis and ESCA. Zn metals were oxidized with the ratio of ca. 50%. As the result of a migration test examined in distilled water, the reaction starts after 1 min in a fired silver electrode, 9 min in a Cu plating electrode and in a Zn-Cu electrode, and more than 15 min in a fired Zn electrode.