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951.
New films of iron complex with 4,7-bis(2-aminophenyl)-methylaminosulfonylphenyl)-1,10-phenanthroline (APP) and 5-amino-1,10-phenanthroline (AP) are prepared on the electrode surface of In–Sn oxide conducting glass (ITO) by electrochemical oxidation. The thickness (Φ) of the films prepared on the ITO can be controlled by the number of cycles of the potential scan. The resulting film-coated electrodes show well-defined reversible vol-tammograms corresponding to the redox reaction of the Fe(II/III) complexes in 0.1 M NaClO4 acetonitrile (AN), a mixture of butylene carbonate (BC) and propylene carbonate (PC) and poly2-hydroxyethylmethacrylate gel containing BC and PC. The electron transfer processes within the films can be treated apparently as diffusional processes characterized by the rate constants of the apparent diffusion coefficient (Dapp). The value of Dapp increase from 1.0 × 10?9 to 1.6 × 10?8 cm2 sec?1 as the Fe complex concentration (CFe) increases from 0.06 to 1.04 M for the [Fe(AP)3] complex film (Φ=0.80 μm) in 0.2 M NaClO4/AN solution. The Dapp value for the [Fe(APP)3) complex film (CFe = 0.19 M , Φ= 0.78 μm) is 3.5 × 10?9 cm2 sec?1 in 0.2 M NaClO4/AN solution. The Dapp values of the [Fe(AP)3] complex film in the PC + BC mixture and gel containing 1.0 M NaClO4 were smaller than those obtained in AN solution by an order of magnitude. The dependence of the apparent formal potential of the Fe(II/III) redox reaction for the [Fe(AP)3] complex film on the activity of NaClO4 supporting electrolyte in AN shows that Na+ moves preferentially across the polymer/solution interfaces during the redox reaction. The Fe(II/III) redox reaction of the Fe complex films shows reversible electrochromic response between red and colorless. 相似文献
952.
Mitsuru Mimura Hiroshi Urakawa Kanji Kajiwara Shinichi Kitamura Kenichi Takeo 《Macromolecular Symposia》1995,99(1):43-55
(1→4)-α- and (1→4)-β-D-linked glucosidic oligosaccharide chains were generated by the Monte Carlo method, and the scattering from the systems composed of simulated chains was calculated to compare with the results of small-angle X-ray scattering from the oligosaccharides in aqueous solution. By extending the simulation to a longer chain, a single chain conformation of (1→4)-α- and (1→4)-β-D-linked polysaccharides was evaluated. On the basis of the simulation, the suprastructure of (1→4)-α- and (1→4)-β-D-linked polysaccharides and their gel formation mechanism were discussed in some detail by analyzing the small-angle X-ray scattering from the aqueous solutions of (1→4)-α- and (1→4)-β-D-linked polysaccharides. 相似文献
953.
Formation of Anatase Nanocrystals in Sol-Gel Derived TiO2-SiO2 Thin Films with Hot Water Treatment 总被引:8,自引:0,他引:8
Yoshinori Kotani Atsunori Matsuda Masahiro Tatsumisago Tsutomu Minami Taku Umezawa Toshihiro Kogure 《Journal of Sol-Gel Science and Technology》2000,19(1-3):585-588
We have successfully prepared transparent and porous anatase nanocrystals-dispersed films by treating the sol-gel derived TiO2-SiO2 films containing poly(ethylene glycol), PEG, with hot water. This process was done at temperatures lower than 100°C under atmospheric pressure, and thus anatase nanocrystals-dispersed films can be formed on various kinds of substrates including organic polymers with poor heat resistance. The changes in structure and composition of the TiO2-SiO2 gel films with hot water treatment were related to the formation process of anatase nanocrystals in the TiO2-SiO2 gel films with hot water treatment. The formation of anatase nanocrystals was found to proceed to hydrolysis of Si–O–Ti bonds and dissolution of SiO2 component. In addition, porous film structure formed by leaching of PEG with hot water treatment led to homogenous dispersion of anatase nonocrystals in the films. 相似文献
954.
The effect of the polarization electric field on helix-unwinding in a thin planar chiral smectic C liquid-crystal cell is studied by using the nematic-like expression for the elastic deformation free-energy density. It is found that the elongation of the helical pitch when the cell thickness decreases is greater when the spontaneous polarization is larger. This is due to the Coulomb repulsion between polarization charges concentrated at ± 2π disclinations. 相似文献
955.
Masahiro Hasegawa Kunio Arai Shozaburo Saito 《Journal of polymer science. Part A, Polymer chemistry》1987,25(12):3231-3239
The encapsulation of fine inorganic powder was carried out with the soapless emulsion polymerization of methyl methacrylate in water in the presence of the powder, a layer of surfactant being adsorbed. The powder used was titanium dioxide. Surfactants added prior to the polymerization were sodium dodecyl sulfate, dodecyltrimethyl ammonium bromide, and polyoxyethylene sorbitan mono-oleate. The encapsulation state of the powder with polymer was closely related to the amount of surfactant adsorbed on the powder; and an amount of adsorption above a certain value was necessary for uniform encapsulation. Ionic surfactants were more useful than nonionic in the surfactants used, and could be adsorbed utilizing the electrostatic interaction between powder and the ionic end group. The combination of electric charges between the ionic end groups of surfactant and initiator was found to influence the molecular weight of capsulating polymer. 相似文献
956.
Accurate Slater type function (STF) Hartree-Fock (HF) wavefunctions are calculated and tabled from B to Ca. The STF's have a form of r
n
e
-r
and the powers (n) of r are carefully determined. The total atomic energies agree with those of numerical HF (NHF) within the error of 4×10–6 a.u. and 1×10–5 a.u. for B to F and for Ne to Ca, respectively. The STF HF basis sets given will be useful to benchmark calculations for the molecular, solid, and atomic electronic states. Applications of the STF HF basis to molecular calculations are given and briefly discussed. Sample calculations are performed on the N2 and P2 molecules. 相似文献
957.
958.
959.
960.
Minoru Sasaki Masahiro Miyazawa Keiji Tanino Masaaki Miyashita 《Tetrahedron letters》1999,40(52):5533-9270
A stereoselective alkynylation reaction of rans-1-phenylthio-2,3-epoxyalkanes with alkynylaluminums which proceeds via episulfonium ions, that is, with double inversion of configuration, has been developed. 相似文献