In order to establish the sequential hydrogen production from waste starch using a hyperthermophile, Pyrococcus furiosus, and a photosynthetic bacterium, basic studies were done. P. furiosus produced hydrogen and acetate by anaerobic fermentation at 90°C. A photosynthetic bacterium, Rhodobacter sphaeroides RV, was able to produce hydrogen from acetate under anaerobic and light conditions at 30°C. However, Rb. sphaeroides RV was not able to produce hydrogen from acetate in the presence of sodium chloride that was essential for the growth and hydrogen production of P. furiosus although it produced hydrogen from lactate at a reduced rate with 1% sodium chloride.
A newly isolated strain, CST-8, from natural environment was, however, able to produce hydrogen from acetate, especially with 3 mM L-alanine and in the presence of 1% sodium chloride. The sequential hydrogen production with P. furiosus and salt-tolerant photosynthetic bacteria could be probable at least in the laboratory experiment scale.

抄録全体を表示

Blends of isotactic polypropylene (iPP) and polydimethylsiloxane (PDMS) are usually immiscible and have phase-separated morphology. In this study, the composite comprising iPP and PDMS with a hydrophobic surface was developed. This composite was obtained by a synthetic method using supercritical carbon dioxide. Results of attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) indicated that PDMS was formed within the iPP substrate. Differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS) measurements showed that iPP and PDMS were blended at the nanometer level. Water dynamic contact angle (DCA) measurement revealed that the hydrophobicity of iPP had been improved by incorporating PDMS.

抄録全体を表示

Poly[2]catenanes consisting of the Leigh's isophthalamide-type [2]catenane with various bridging groups were synthesized. The bridging groups included esters, amides, 1,2,3-triazoles, ethynylenes, and 4,4'-biphenylenebis(triazoles). The polycondensation and coupling polymerization reactions proceeded effectively under mild conditions and gave the expected polymers in good yields. The number average molecular weight of the polymers ranged between approximately 7.2×10³ and 3.5×10⁴ and was highest for the 4,4'-biphenylenebis(triazole) bridging group. Cyclic dimers consisting of two [2]catenane moieties and two bridging units often formed along with the polymers. Performing the reaction at lower temperatures suppressed the cyclodimerization without lowering the yield or molecular weights of the polymers.

抄録全体を表示

Red-emitting Eu³⁺-activated amorphous barium strontium silicate phosphors were synthesized by heating Eu³⁺-activated barium strontium hydrate silicate phosphors synthesized in liquid phase reaction by adding Na₂SiO₃ solution to a mixture solution of BaCl₂, SrCl₂ and EuCl₃. Eu²⁺-activated amorphous barium strontium silicate phosphors were obtained by performing reduction treatment of the Eu³⁺-activated amorphous barium strontium silicate phosphors under hydrogen-argon atmosphere. The emission spectra were broad and assigned to Eu²⁺. It was possible to control a green region of 504 to 525 nm. In Ba/Sr atomic ratio of 2, barium strontium silicate phosphors emitted green light of broad spectra at 515 nm and has excitation band in near-UV region at 370-430 nm. These results suggest that the reduced phosphors are a promising material as a green phosphor for combining with near-UV LEDs.

抄録全体を表示

In this article, I will present an account of my attempts in the last 15 years to control electronic processes in metal complexes. These works aim at realizing efficient electron transfer systems that could give rise to artificial photosynthetic devices and at creating responsive electronic systems that could lead to molecular electronic devices. Metal complexes are used throughout because of their well-defined geometry as well as unique electronic states resulting from the interaction of d orbitals in the metal and π orbitals in the ligands. Electron transfer systems and molecular switching systems are described followed by immobilization and organization of metal complexes onto surfaces.

抄録全体を表示