Highly ion conductive flexible films composed of network polymers based on polymerizable ionic liquids

Ionic liquid-type polymer brushes having different hydrocarbon (HC) chain lengths between polymerizable group and imidazolium ring were synthesized. When the carbon number of HC chain was 6, the ionic liquid-type polymer brush exhibited the highest ionic conductivity of 1.37×10⁻⁴ S cm⁻¹ at 30 °C, reflecting low T_g of −60 °C. Moreover, for the first time, we succeeded in obtaining transparent and flexible films without considerable decrease in the ionic conductivity as compared with that of corresponding monomers by using suitable cross-linkers. The most ion conductive (1.1×10⁻⁴ S cm⁻¹ at 30 °C) film was obtained when tetra(ethylene glycol)diacrylate was used 0.5 mol% to ionic liquid monomer as the cross-linker. This film is one of excellent conductive films among single-ion conductive materials.     

Study of the properties of nickel oxide and nickel as precursors for the tartaric acid-NaBr-modified nickel catalyst

Nickel oxide was prepared by the decomposition of nickel hydroxide and then the nickel oxide was reduced to form the nickel catalyst. The properties of the nickel oxide and the reduced nickel were studied in relation to the enantio-differentiating ability (e.d.a.) of a tartaric acid-NaBr-modified reduced nickel catalyst. The modified nickel catalyst prepared from nickel oxide with less non-stoichiometric oxygen produced a high e.d.a. for the hydrogenation of methyl acetoacetate. The high crystallinity of the nickel oxide and the resultant nickel would be required to attain a high e.d.a.     

Contribution of primary radical termination to radical polymerization of diethyl fumarate estimated from absolute rate constants

Summary Diethyl fumarate was radically polymerized under UV irradiation and concentration of the propagating radical was determined to be of the order of 10^-5 mol/L by scavenge with a stable free radical. The absolute rate constant for propagation (k_p) was evaluated from the overall rate of polymerization at 30°C: K_p =(2.9 ± 0.3) × 10^-2 L/mol · s. The rate constant for mutual termination of the polymer radical (k_t) was calculated from the decreasing rate of the radical concentration in the dark: k_t=8.0 L/mol·s. The k_t value determined is one twentieth of that evaluated previously by a rotating sector method. This discrepancy is accounted for by contribution of much faster primary radical termination.     

Intermediate hydrocarbon species for the CO2-CH4 reaction on supported Ni catalysts

By using pulse surface reaction rate analysis (PSRA), the detailed structure of the intermediate hydrocarbon species was revealed by measuring the dynamic behavior of both CO and H₂ produced from the CO₂-CH₄ reaction on supported Ni catalysts. It was found that the number of hydrogen atoms involved in the intermediate was different from one catalyst support to another: 2.7 for MgO, 2.5 for ZnO, 2.4 for Al₂O₃,1.9 for TiO₂, and 1.0 for SiO₂.     

Influence of oxidation temperature on the gas permeation and separation properties in a microporous carbon membrane

Of thermosetting polymers, polyphenylene oxide (PPO) is considered as one of the promising alternative polymeric precursors for carbon membrane preparation. In this study, the PPO derived carbon membranes were prepared by carbonization and followed by air-oxidation as post-treatment method to modify the membrane pore structures. The characterization of the pore properties showed that air-oxidation enlarged the pore structure for the postoxidized carbon materials. The permeation results for the post-oxidized carbon membranes showed that the extent of the permeation modification was strongly dependent on the oxidation temperature. In the binary mixture gas systems, the permeation performance of the adsorbing gas species increased due to the surface diffusion mechanism. It is considered in the oxidation effect on the permeation modification that the post-oxidation of the carbon membranes increased gas permeation and separation properties.     

Effect of a low-fat diet enriched with oleic acid on postprandial lipemia in patients with type 2 diabetes mellitus

The aim of the present study was to compare the effects of a low-fat diet enriched with oleic acid to those of a low-fat diet enriched with linoleic acid on fasting lipids, postprandial lipemia, and oxidative susceptibility of low-density lipoprotein (LDL) in patients with type 2 diabetes mellitus (DM). In a 3-wk randomized crossover study, eight patients with type 2 DM were given an experimental low-fat diet enriched with either oleic acid or linoleic acid. The oleic-acid-enriched diet contained 5, 15, and 5% energy from saturated, monounsaturated, and polyunsaturated fatty acids, and the linoleic-acid-enriched diet contained 5, 5, and 15% energy from saturated, monounsaturated, and polyunsaturated fatty acids, respectively. In addition to evaluating the fasting lipids and oxidative susceptibility of LDL, we evaluated postprandial lipemia using an oral fat load at the end of each 3-wk dietary phase. There were no significant differences in fasting lipid profile or lag time of LDL oxidation between the two experimental dietary phases. The average and maximal increments of remnant-like particle (RLP) cholesterol levels during oral fat load were significantly higher after the oleic-acid-enriched dietary phase than after the linoleic-acid-enriched dietary phase. The area under the curve of RLP cholesterol was also significantly larger after the oleicacid-enriched dietary phase than after the linoleic-acid-enriched dietary phase. These results suggest that the oleic-acidenriched diet was associated with increased formation of postprandial chylomicron remnants compared with the linoleicacid-enriched diet.     

Plasma etching treatment for surface modification of boron-doped diamond electrodes

Boron-doped diamond (BDD) thin film surfaces were modified by brief plasma treatment using various source gases such as Cl₂, CF₄, Ar and CH₄, and the electrochemical properties of the surfaces were subsequently investigated. From X-ray photoelectron spectroscopy analysis, Cl and F atoms were detected on the BDD surfaces after 3 min of Cl₂ and CF₄ plasma treatments, respectively. From the results of cyclic voltammetry and electrochemical AC impedance measurements, the electron-transfer rate for Fe(CN)₆^3−/4− and Fe^2+/3+ at the BDD electrodes was found to decrease after Cl₂ and CF₄ plasma treatments. However, the electron-transfer rate for Ru(NH₃)₆^2+/3+ showed almost no change after these treatments. This may have been related to the specific interactions of surface halogen (C-Cl and C-F) moieties with the redox species because no electrical passivation was observed after the treatments. In addition, Raman spectroscopy showed that CH₄ plasma treatment of diamond surfaces formed an insulating diamond-like carbon thin layer on the surfaces. Thus, by an appropriate choice of plasma source, short-duration plasma treatments can be an effective way to functionalize diamond surfaces in various ways while maintaining a wide potential window and a low background current.     

Energy value and digestibility of dietary oil containing mainly 1,3-diacylglycerol are similar to those of triacylglycerol

Diacylglycerol (DAG) is a component of various vegetable oils. Approximately 70% of the DAG in edible oils are in the configuration of 1,3-DAG. We recently showed that long-term ingestion of dietary oil containing mainly 1,3-DAG reduces body fat accumulation in humans as compared to triacylglycerol (TAG) oil with a similar fatty acid composition. As the first step to elucidate the mechanism for this result, we examined the difference in the bioavailabilities of both oils by measuring food energy values and digestibilities in rats. Energy values of the DAG oil and the TAG oil, measured by bomb calorimeter, were 38.9 and 39.6 kJ/g, respectively. Apparent digestibility expressed according to the formula: (absorbed) x (ingested)⁻¹x100=(ingested—excreted in feces)x(ingested)⁻¹x100 for the DAG oil and the TAG oil were 96.3±0.4 and 96.3±0.3% (mean±SEM), respectively. The similarity in the bioavailabilities of both oils supports the hypothesis that the reduced fat accumulation by dietary DAG is caused by the different metabolic fates after the absorption into the gastrointestinal epithelial cells.     

Improved synthetic method and conformation studies of polymers and copolymers of l-β-3,4-dihydroxyphenyl-α-alanine with l-glutamic acid

Eight different copolymers of l-β-3,4-dihydroxyphenyl-α-alanine (l-Dopa) and l-glutamic acid with high degrees of polymerization have been synthesized by the treatment of a series of $\text{copoly}\text{(O,O′-}\text{dimethyl-}\text{l}\text{-Dopa}$, γ-benzyl-l-glutamate) with boron tribromide in chloroform. The conformation of poly(l-Dopa) has been established to be a right-handed helix in trimethyl phosphate on the basis of the following observations. The [θ]₂₂₂ and b₀ values of the copolymers were almost linear with composition in trimethyl phosphate. The linear relationship between the rotation properties and composition indicates that poly(l-Dopa) has the same helical sense as that of poly(l-glutamic acid) which is a right-handed α-helix.