竹岡 裕子

Zwitterions with a cyano group on the side chain (CZ) were synthesized. Although the addition of CZ caused a slightly negative effect on viscosity, ionic conductivity, limiting current density, and lithium transference number, the oxidation limit of PEGDME/lithium bis(trifluoromethylsulfonyl) amide (LiTFSA) composites was improved to over 5 V. For charge/discharge testing using Li vertical bar electrolyte vertical bar LiCoO2 cells, the cycle stability of PEGDME/LiTFSA with CZ in the voltage range of 3.0-4.6 V was much higher than that of PEGDME/LiTFSA. Incorporating a small mole fraction of CZ into PEGDME-based electrolytes prevented an increase in the interface resistance between the electrolyte and cathode with increasing numbers of the cycle. (C) 2015 Elsevier Ltd. All rights reserved.

Solid polymer electrolytes show great potential in electrochemical devices. Poly(ethylene oxide) (PEO) has been studied as a matrix for solid polymer electrolytes because it has relatively high ionic conductivity. In order to investigate the effect of zwitterions on the electrochemical properties of poly (ethylene glycol) dimethyl ether (G5)/lithium bis(fluorosulfonyl) amide (LiFSA) electrolytes, a liquid zwitterion (ImZ2) was added to the G5-based electrolytes. In this study, G5, which is a small oligomer, was used as a model compound for PEO matrices. The thermal properties, ionic conductivity, and electrochemical stability of the electrolytes with ImZ2 were evaluated. The thermal stabilities of all the G5-based electrolytes with ImZ2 were above 150 degrees C, and the ionic conductivity values were in the range of 0.8-3.0 mS cm(-1) at room temperature. When the electrolytes contained less than 5.5 wt% ImZ2, the ionic conductivity values were almost the same as that of the electrolyte without ImZ2. The electrochemical properties were improved with the incorporation of ImZ2. The anodic limit of the electrolyte with 5.5 wt% ImZ2 was 5.3 V vs. Li/Li+, which was over 1 V higher than that of G5/LiFSA. (C) 2014 Elsevier Ltd. All rights reserved.

We have measured the temperature dependence of the reflection and photoluminescence spectra of a lead bromide hybrid material (CH3NH3PbBr3) using high-quality macroscopic single crystals. Single crystals provide clear and sample-independent reflection spectra that permit discussion of the properties of the photoexcited carriers. We have found that excitons still exist in CH3NH3PbBr3, even at room temperature. We have also determined the temperature dependence of the exciton resonance energy and the line width.

Poly(L-lactic acid-co-glycolic acid)/hydroxyapatite (PLGA/HAp) composites were fabricated by the in situ polymerization of L-lactide and glycolide in porous HAp disks, using lipase MM, derived from Mucor miehei, as a catalyst. Various PLGA/HAp composites were obtained by changing the feed ratio of L-lactide and glycolide. The fourier transform infrared spectroscopy, scanning electron microscopy and porosity measurements showed that the porous HAp was completely filled with PLGA after polymerization at 100 degrees C for 9 days. Lactyl unit fractions (FL) of obtained PLGA calculated from the 1H nuclear magnetic resonance were consistent with the feed fraction of L-lactide (fL). The PGA/HAp, PLGA20/HAp, PLGA50/HAp, PLGA80/HAp and PLLA/HAp composites showed maximum bending strengths of 91.1 MPa, 78.8 MPa, 73.4 MPa, 54.3 MPa and 67.0 MPa, respectively. These values were 4.7-2.8 times greater than that of the untreated porous HAp disks and were suitable for artificial bone materials. The cell adhesion and proliferation properties of these materials with osteoblast-like MC3T3-E1 cells suggest that these PLGA/HAp composites have suitably bioactive surfaces. The PLGA/HAp composites showed higher alkaline phosphatase activity after cultivation of rat bone marrow stromal cells.

In order to investigate the effects of lithium salt species and concentration on the electrochemical properties of a liquid zwitterion (LZw), composites of a LZw with lithium bis(fluorosulfonyl) amide (LiFSA) or lithium bis(trifluoromethylsulfonyl) amide (LiN(Tf)(2)) were prepared at various lithium salt concentrations. The majority of LZw/LiFSA and LZw/LiN(Tf)(2) composites with lithium salt mole fractions in the range of 0.2 to 0.8 were obtained as colorless liquids and exhibited glass transitions only during DSC measurements. The dissociation state of the lithium salts in the composites was discussed by means of FT-IR measurements. The interactions between the imidazolium cation and the amide anions were demonstrated. The LZw/LiFSA composite with a LiFSA mole fraction of 0.8 (corresponding to a concentration of 13.7 mol kg(-1)) exhibited the highest ionic conductivity (1.2 x 10(-5) S cm(-1)) as well as the greatest lithium transference number (0.46) at 40 degrees C.

A new ionic liquid was prepared by introducing a boronic acid group to an imidazolium cation with a hydrophobic anion. The boronic acid-containing ionic liquid showed the best ionic conductivity of 6.5 x 10(-4) S cm(-1) at 50 degrees C, with a high lithium ion transference number of over 0.5, owing to the anion-trapping effect of the boronic acid group.

Poly(L-lactic acid)/hydroxyapatite (PLLA/HAp) composites were fabricated by in situ polymerization of L-lactide in porous HAp disks, using lipase as a catalyst. The effect of using various lipase species on the molecular weight of the resulting PLLA was investigated, as was the effect of varying the lipase concentration. Lipase CA, derived from Candida antarctica, was found to promote the polymerization of L-lactide in bulk form as well as within porous HAp disks. The in situ polymerization of L-lactide within lipase CA-coated HAp disks at 130 degrees C for 7 days resulted in PLLA/HAp composites with a PLLA content in the range of 16 to 19 wt.%. The weight average molecular weights of the PLLAs formed in these composites were in the range of 1.6 x 10(4) to 3.0 x 10(4) g mo1-1 and varied with the lipase CA concentration. The PLLA/HAp composites exhibited a maximum bending strength of 72 MPa and a fracture toughness value of 0.93 MPa m(1/2), as estimated by three point bending tests. The cell adhesion and proliferation properties of these materials with osteoblast-like MC3T3-E1 cells suggest that these PLLA/HAp composites have suitably bioactive surfaces.

We have investigated experimentally excitonic properties in organic-inorganic hybrid multi quantum well crystals, (C4H9NH3)(2)PbBr4 and (C6H5-C2H4NH3)(2)PbBr4, by measuring photoluminescence, reflectance, photoluminescence excitation spectra. In these materials, the excitonic binding energies are enhanced not only by quantum confinement effect (QCE) but also by image charge effect (ICE), since the dielectric constant of the barrier layers is much smaller than that of the well layers. By comparing the 1s-exciton and 2s-exciton energies, we have investigated the influence of ICE with regard to the difference of the Bohr radius.

We synthesized sulfonated poly[(4-phenoxybenzoyl)-1,4-phenylene-co-anthraquinone] copolymers (S-P(PBP-co-ANQ)s) in order to investigate the effect of polycyclic units on the water uptake, dimensional stability, and proton conductivity. The effect of the binding positions of anthraquinone (ANQ) was also investigated by preparing S-P(PBP-co-1,4ANQ) and S-P(PBP-co-1,5ANQ), each with 5 mol% ANQ. Number-average molecular weights and thermal decomposition temperatures of S-P(PBP-co-ANQ)s were about 50-70 kgmol(-1) and 220 degrees C, which were sufficient for polymer electrolyte fuel cell (PEFC) applications. S-P(PBP-co-1,5ANQ) membranes showed higher dimensional stability and proton conductivity than S-P(PBP-co-1,4ANQ) and S-PPBP membranes. The maximum current densities and power densities of S-P(PBP-co-1,5ANQ) fuel cells were 2200mA cm(-1) and 800 mW cm(-2) at 80 degrees C and 100% relative humidity. These results suggest that the improvement of dimensional stability and electrochemical properties is due to strong aggregation of the copolymer chains induced by ANQ at an appropriate coupling position.

Novel organic-inorganic hybrid compounds, C16H44N4Pb3I10 and C14H34N2Pb2I6, were synthesized by solvent diffusion recrystallization from the dimethylsulfoxide solution containing PbI2 and gemini ammonium surfactants with different head groups. The results of single crystal X-ray structural analysis showed that the inorganic region of C16H44N4Pb3I10 has quasi one-dimensional chains of [Pb3I10](4-) units, whereas that of C12H30N2Pb2I6 has one-dimensional chains of face-sharing PbI6 octahedra. The absorption and fluorescence spectra of these compounds also indicate the formation of one-dimensional inorganic chains and quantum-confined structures. (C) 2012 Elsevier Ltd. All rights reserved.

A chiral polyfluorene-thiophene derivative incorporating two different chiral side chains was synthesized via the Suzuki coupling reaction. Upon photoexcitation, thin films of the polymer exhibited efficient circularly polarized luminescence in the visible range, even without thermal annealing. The dissymmetry factor, g(lum), of films with thicknesses less than 100 nm reached 0.2 at 505 nm.

Layered perovskite (RNH 3)2PbI 4 (R = organic cation), which contained the fullerene derivatives, [ethyl-3-tert- butoxycarbonylaminopropyl (1,2-methanofullerene C 60)]-61,61-di carboxylate iodide (EAF-I) and di[3-tert-butoxycarbonylaminopropyl (1,2-methanofullerene C 60)]- 61,61-dicarboxylate diiodide (DAF-I 2) in the organic layers were fabricated and compared with previously reported perovkite compound containing N-methyl-2-(4-aminophenyl)- fulleropyrrolidine iodide (AmPF-I). Because the solvent solubilities of EAF-I and DAF-I 2 to N,N-dimethylformamide (DMF) were higher than AmPF-I, the film processability of EAF-I and DAF-I 2 was improved compared with AmPF-I. The X-ray diffraction patterns proved the construction of the perovskite structure in (EAF) 2PbI 4 and (AmPF) 2PbI 4 cast films. EAF was well-organized and closer-packing than AmPF in the perovskite structure. For the diamine-type fullerene, DAF-I 2, it is difficult to form layered structure by spin-coated or cast methods. New sharp X-ray diffraction peaks were observed for DAF-I 2 films dipped in PbI 2 solution. The intercalations and formation of perovskite structure of (DAF)PbI 4 were studied. © (2012) Trans Tech Publications, Switzerland.

Oligothiophene derivatives, 4,4′-bis-(2-aminoethylthienyl)-3,4- ethylenedioxythiophene dihydrohalide (AET-EDOT·HX: X = I, Br), were synthesized by Grignard coupling reactions. The hybrid films of oligothiophene and lead halide were fabricated by casting and spin-coating methods. The effect of halogen species on the optical properties of the perovskites was investigated. The X-ray diffraction profiles of (AET-EDOT)PbX 4 cast films indicated that the layered structures were formed by the self-organization. After hybridization of AET-EDOT·HX with PbX 2, new absorption peaks due to the confined excitons were observed at 400 nm for (AET-EDOT)PbBr 4 film, and at 395 nm for (AET-EDOT)PbI 4 film. These results indicated that the diamino-type oligothiophenes were successfully incorporated into the organic-inorganic layered perovskites. AFM images of (AET-EDOT)PbX 4 cast films showed polycrystalline grains, indicating that the polycrystalline structures covered on the substrate surface. © (2012) Trans Tech Publications, Switzerland.

Fluorene-thiophene copolymers having chiral and azobenzene substituents, PAzB4-T, were synthesized by the Pd-catalyzed Suzuki coupling method. We studied the aligning organization of the main chain of PAzB4-T with the activation of the attached functional groups by thermal annealing and photo-annealing processes. Circular dichroism (CD) measurements revealed that the thermally annealed PAzB4-T spin-coated films exhibited bisignate Cotton effects over the absorption regions of the polymer main chains and the azobenzene side chains due to the formation of chiral assemblies. After the photo-annealing process, which means linearly polarized light irradiation accompanied by thermal annealing, the PAzB4-T spin-coated films showed linear dichroism over the absorption region of the main chains, due to the alignment of azobenzene side chains against the electric field of the linearly polarized light. These results suggested that rigid conjugated polymers were successfully aligned by the alignment of functional groups with the external stimuli.

We employed the pulsed field gradient nuclear magnetic resonance (PFG-NMR) technique to investigate the self-diffusion coefficient of water, D NMR, in newly designed cation exchange membranes, made of sulfonated poly(p-phenylene)-poly(ether ketone) multiblock copolymers, which are denoted by S-6H (n) x:y. The DNMR value was measured as a function of the gradient strength, g, from 0.1 to 11.0 T m-1. S-6H (14) 1:1 showed the DNMR value of 2.35 × 10-10 m2 s -1 at 30 °C and 90% RH, which are about 10 times lower than the value in bulk liquid water. Small angle neutron scattering (SANS) measurements showed two peaks in S-6H (14) 1:1. The low q peak is attributed to the formation of microdomains and the high q peak is due to the formation of ionic clusters in the swollen microdomains.

We synthesized a new sulfonated phenylene block copolymer (S-PPBP-PES) by a Ni(0) coupling reaction. Membrane electrode assemblies (MEAs) were fabricated with the S-PPBP-PES ionomer and a Nafion 112 membrane. Five alcohols (methanol, ethanol, 1-propanol, 2-propanol, or mixed propanol) were used as the dispersion solvent for catalyst ink, and the effect of solvents on the fuel cell performance was investigated. These MEAs prepared with mixed propanol exhibited the highest power density among them due to the larger electrochemically active area and smooth surfaces of the catalytic layer compared with others. © The Electrochemical Society.

A poly(p-phenylene)-based diblock copolymer P2-P1 was synthesized with a hydrophilic monomer, 2,5-dibromo-1,4-di[4-(2, 2-dimethylpropoxysulfonyl)phenyl] butoxybenzene, and a hydrophobic monomer, 2,5-dibromo-1,4-dihexyloxybenzene, via a catalyst transfer polycondensation. Deprotection of the neopentyl groups using diethylamine hydrobromide and subsequent acidic hydrolysis provided a sulfonated diblock copolymer SP2-P1. The diblcok copolymer SP2-P1 showed similar hydration numbers λ to the random copolymer SP2-RAN-P1 in the rage of 30-90% RH at 80°C. The proton conductivity of the SP2-P1 was higher than that of SP2-RAN-P1 membranes at 80°C despite of the lower IEC and the comparable λ. © The Electrochemical Society.

Ni(0)-catalyzed coupling polymerization of 2,5-dichloro-4'-phenoxybenzophenone was investigated by varying the ligand and coligand, temperature, reaction time, and solvent. The weight-average molecular weight (M-w) of poly(4-phenoxybenzoyl-1,4-phenylene)s (PPBPs) could be controlled by the polymerization conditions and reached a maximum of 4.4 x 10(5) g mol(-1). Sulfonated PPBPs (S-PPBPs) with various M(w)s were prepared with sulfuric acid to study the effect of molecular weight on the chemical and electrical properties of PPBP-based electrolytes. The strong molecular interactions in S-PPBP provided an ion exchange capacity of 2.9 meq g(-1) without loss of high mechanical properties. High molecular weight S-PPBPs had more desirable properties for fuel cell applications. While the swelling ratios and hydration numbers of S-PPBPs decreased with increasing molecular weight, the mechanical strength, proton conductivity, and fuel cell performance increased. S-PPBP also showed anisotropic behavior in the swelling and proton conductivity; such behavior is caused by the rigid-rod nature and the liquid-crystal structure. (C) 2011 Elsevier Ltd. All rights reserved.

Optical properties in a single crystal of the organic-inorganic hybrid perovskite quantum-well material (C4H9NH3)(2)(CH3NH3)Pb2Br7 have been investigated. This material has double-layer sheets of corner-sharing [PbBr6](4-) octahedrons constituting the inorganic well. The estimated longitudinal-transverse (LT) splitting, exciton exchange energy, and biexciton binding energy are about 60 meV, 17 meV and 26 meV respectively. We can also study well-width dependence in angstroms by comparing with (C4H9NH3)(2)PbBr4 which has single-layer sheets comprising the inorganic well. This is the first time the well-width dependence of excitonic properties in hybrid organic-inorganic quantum materials is investigated. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

We have developed the porous HAp ceramics with bi-modal pore structure. Using the porous HAp ceramics, HAp/poly-L-lactide (PLLA) hybrids were fabricated by introducing PLLA into the porous HAp ceramics via enzyme polymerization of L-lactide using lipase (lipase PS) as an enzyme. The amount of lipase PS was added 1 and 3 mass% to weight of L-lactide. In order to examine the changes of material properties before and after immersing into the simulated body fluid (SBF), we fabricated three kinds of specimens: i) Porous HAp, ii) HAp/PLLA(1%), iii) HAp/PLLA(3%). The bending strength of the hybrids decreased during immersing SBF up to 28 days. Furthermore, when the hybrids were immersed into the SBF for 4 days, the formation of bone-like apatite occurred on the surface of the specimens.

An imidazolium-based zwitterion containing two oxyethylene units was obtained as a colorless liquid at room temperature. The equimolar mixture of the liquid zwitterion and lithium bis(trifluoromethylsulfonyl) amide showed an ionic conductivity of over 10(-4) S cm(-1) at 80 degrees C, which was higher than those of mixtures composed of analogous solid zwitterions.

An ionic liquid having a hydroxyl group, choline bis(trifluoromethylsulfonyl)amide ([N-111(2OH)][N(Tf)(2)]), was synthesized to investigate the effect of hydroxyl groups on the proton transport. 1,1,1-Trifluoro-N-(trifluoromethylsulfonyl)methanesulfoneamide (HN(Tf)(2)) as a proton source was mixed with the choline derivative at various molar ratios. Their thermal properties, viscosities, and ionic conductivities were investigated. [N-111(2OH)][N(Tf)(2)] showed a melting point at 27 degrees C, and its thermal stability was higher than 400 degrees C. The viscosity of [N-111(2OH)][N(Tf)(2)]/HN(Tf)(2) mixtures increased as the acid molar fraction increased. The ionic conductivity of [N-111(2OH)][N(Tf)(2)] was 2.1 x 10(-3) S cm(-1) at 25 degrees C; the ionic conductivity monotonously decreased as the acid molar fraction increased. There was a clear correlation between the ionic conductivity and the viscosity for the mixtures of the choline derivative and the acid. PFG-NMR measurements were carried out to investigate the diffusion behavior of protons. Although the acid and the hydroxyl group were indistinguishable by H-1 NMR, the self-diffusion coefficient of the H-1 of the hydroxyl group and the acid was larger than those of other H-1 nuclei. This difference suggests that a fast intermolecular proton transfer exists between the hydroxyl group and the acid.

Optical properties in a single crystal of the organic-inorganic hybrid perovskite quantum-well material (C4H9NH3)(2)(CH3NH3)Pb2Br7 have been investigated. This material has double-layer sheets of corner-sharing [PbBr6](4-) octahedrons constituting the inorganic well. The estimated longitudinal-transverse (LT) splitting, exciton exchange energy, and biexciton binding energy are about 60 meV, 17 meV and 26 meV respectively. We can also study well-width dependence in angstroms by comparing with (C4H9NH3)(2)PbBr4 which has single-layer sheets comprising the inorganic well. This is the first time the well-width dependence of excitonic properties in hybrid organic-inorganic quantum materials is investigated. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Multilayer-type polymer electrolyte membranes composed of a sulfonated poly(4-phenoxybenzoyl-1,4-phenylene) (S-PPBP) layer and a mono[ poly(propylene oxide)methacrylate] phosphate ester (PPHP) layer were fabricated by solution-casting procedure (Method 1) and hot-pressing procedure (Method 2) in order to suppress methanol permeability of electrolyte membranes. No delamination was observed by SEM measurements of S-PPBP/PPHP interfaces, indicating that PPHP had good adhesive properties to S-PPBP surfaces. The methanol permeability of S-PPBP/PPHP membranes was lower than that of S-PPBP membranes and decreased with increasing the thickness of PPHP layers. The bilayer membrane with 12 mu m PPHP and 40 mu m S-PPBP layers showed a methanol permeability of 2.97 x 10(-7) cm(2) s(-1) in 1 mol dm(-3) methanol aqueous solution at 25 degrees C, which was 13% less than that ofthe S-PPBP membranes. The conductivity of this membrane reached its optimum with values as high as 1.57 x 10(-1) S cm(-1) at 80 degrees C and 90%RH. (C) 2009 Elsevier Ltd. All rights reserved.

Poly[9,9-dihexylfluorene-co-(benzothiazol-2-yl)thiophene-co-9,9'-spirobifluorene] (PF(x)B(y)S(z)) were synthesized by palladium-catalyzed Suzuki coupling reaction. PE(x)B(y)S(z) were characterized by FT-IR,elemental analysis, and (1)H NMR. All the copolymers showed decomposition temperatures above 400 degrees C and glass transition points above 180 degrees C. suggesting that these materials had excellent thermal stability. As the benzothiazolylthiophene content in copolymers was increased, the band gaps of copolymers decreased. All the copolymers exhibited fluorescence peaks in the visible region, and the energy transfer from fluorene to benzothiazolylthiophene units were observed. (C) 2009 Elsevier B.V. All rights reserved.

A series of alternating copolymers consisting of chiral thiophene and fluorene, poly[9,9-dihexylfluorene-alt-(3-{2-[(S)-(+)-1-methyloctyloxy]ethyl}thiophene)] (P1), and poly[9,9-dihexylfluorene-alt-(3-{2-[(S)-(+)-1-methyloctyloxy]ethyl}-2,2'-bithiophene)] (P2), were synthesized by Suzuki coupling method. P1 and P2 were characterized by (1)H NMR spectra and elemental analyses. Both of the copolymers showed clear solvatochromism and circular dichroism in methanol/chloroform mixed solutions. These two polymers had different spacer lengths between the chiral side chains along the main chain. and accordingly the circular dichroism spectra were apparently different. (C) 2009 Elsevier B.V. All rights reserved.

The relationships between morphology and proton conduction for Nafion membranes and hydrocarbon-type proton exchange membranes, namely, sulfonated poly(arylene ether ether ketone) (S-PEEK) and sulfonated poly(arylene ether sulfone) (S-PES), were investigated by small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM). The direct simultaneous observation of surface morphology and active regions of proton conduction on membranes by combined high-resolution AFM phase imaging and an electrochemical technique at controlled humidity provided significant morphological information, particularly for the hydrocarbon-type membranes that exhibit few or no features on SAXS profiles. For the Nafion membranes, the active proton paths became denser and congregated with each other at over 60% RH, resulting in the formation of well-connected networks. For the hydrocarbon-type membranes, however, only the relatively small and dispersed proton paths were observed, which showed no significant change even as water content increased. We have demonstrated that the differences in microscopic morphology between the Nafion and hydrocarbon-type membranes are associated with the differences between their macroscopic proton conductivities. (C) 2008 Elsevier Ltd. All rights reserved.