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81.
Daisuke Suzuki Tomoyo Yamagata Koji Horigome Kiyoshi Shibata Akira Tsuchida Tsuneo Okubo 《Colloid and polymer science》2012,290(2):107-117
Influence of the gel size on the morphology, phase diagram, and reflection spectroscopy of the colloidal crystals of thermo-sensitive
gel spheres, poly (N-isopropylacrylamide) (pNIPAm), was discussed by adding the data of two gel samples of pNIPAm(400–5) and pNIPAm(600–5) of
412 nm (at 25 °C) and 220 nm (at 45 °C) and of 517 nm (at 20 °C) and 294 nm (at 45 °C), respectively. Colloidal single crystals
formed, but not so large compared with the giant crystals of small pNIPAm gels reported previously. The suspensions even with
ion-exchange resins were turbid and hard to observe the single crystals clearly with the naked eyes as gel size increased.
The critical concentration of melting decreased sharply as the suspensions were deionized with coexistence of the mixtures
of cation- and anion-exchange resins. The critical concentration increased as the gel size increased and/or dispersion temperature
increased. Density of the gel spheres increased as their size increased. These results demonstrated that the colloidal crystallization
takes place by the extended electrical double layers formed around the gel spheres in addition of the excluded volume effect of the gels. Contribution of the electrical double layers on the crystallization increased sharply as temperature increased
and gel concentration decreased, respectively. The contribution also increased slightly as sphere size increased, when comparison
was made at the same gel concentration in wt.%. The present work clarified that the colloidal interfaces, which are inevitable
for the formation of the electrical double layers, are formed between the water phase and gel spheres, though the gel spheres
contain a lot of water molecules at the inner sphere region. 相似文献
82.
Influence of adding carbon nanotubes on photoelectric conversion properties of dye-doped titania gel
Hiromasa Nishikiori Takuma Ohta Yohei Uesugi Hiroyuki Itai Morinobu Endo Tsuneo Fujii 《Research on Chemical Intermediates》2012,38(8):1857-1869
Multiwalled carbon nanotubes (MWCNTs) were incorporated into amorphous dye-doped titania gel by the sol?Cgel method at room temperature. The working electrodes were prepared by coating the ITO glass with the sol?Cgel titania precursor containing the dye and MWCNTs. The photoelectric conversion properties of the electrodes were examined by simple spectroscopic and electric measurements. The photocurrent spectrum originated from the absorption of the dye. The short circuit photocurrent was enhanced by adding a small amount of MWCNTs evenly to the amorphous dye-doped titania gel. The open circuit voltage was due to the semiconducting characteristics property of the titania gel. The experimental results indicated the electron transport from the dye excited states to the MWCNTs through the titania gel. The MWCNTs functioned as bridges between the titania and ITO. Steam treatment of the titania gel electrodes significantly increased the photoelectric performance due to crystallization of the titania and enhancement of the dye?Ctitania interaction forming the chelate complex on the titania particle surface. 相似文献
83.
Atsushi Ohashi Tsuneo Imamoto 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):723-725
The title compound, C9H22BP, and its coupling product, C16H38B2P2, were synthesized and their crystal structures analyzed by X‐ray diffraction. The molecular structures clearly explain the stereoselective reaction pathways leading to the products. The average P—B distance and C—P—B angle are 1.929 Å and 114°, respectively. 相似文献
84.
Hiromasa Nishikiori Nobuaki Tanaka Tsuneo Fujii 《Research on Chemical Intermediates》2000,26(5):469-482
Dip-coated thin films including rhodamine B have been prepared using the sol-gel reaction of tetraethyl orthosilicate under
relative humidity of 30% and 60%. They have been aged under relative humidity of 20%, 60%, and 95% for 5 days. According to
the absorption spectra, just after the preparation of the films and under higher humidity, a larger amount of the dimers (H-and
J-types) were formed in the films. Five days after the preparation of the films and aged under higher humidity, the H-dimer
increased. On the other hand, the J-dimer increased, regardless of humidity under which the films were aged. 相似文献
85.
Tsuneo Itoh Ikuko Fujii Yasuo Tomii Ichiro Ishikawa Hamo Ogura Yoshihisa Mizuno Norio Kawahara 《Journal of heterocyclic chemistry》1987,24(5):1453-1455
An improved and efficient synthesis of 1,3-dialkylpyrido[2,3-d]pyrimidine-2,4-(1H,3H)-diones from 6-methylaminouracils and methyl propiolate or diethyl ethoxymethylenemalonate is described. 相似文献
86.
87.
Stereoselective reduction of α-substituted β-keto esters is achieved by the combined use of hydrostannane/organotin triflate. syn-Aldols are obtained with more than 90% selectivities. 相似文献
88.
Satoru Nakashima Tsuneo Koura Motomi Katada Hirotoshi Sano Izumi Motoyama 《Hyperfine Interactions》1990,53(1-4):361-366
TCNQ salts of 1-monoalkylbiferrocenes showed a temperature-independent trapped-valence state as expected for the unsymmetrical structure of cations. On the other hand, mixed crystals of 1-monobutyl- and 1.1-dibutylbiferrocenium+(TCNQ)
3
–
showed a temperature dependence of the mixed-valence states, showing that the lattice affects the mixed-valence states. 相似文献
89.
Tsuneo?OkuboEmail author Hiroshi?Kimura Toshinori?Kimura Fumihiro?Hayakawa Tomoaki?Shibata Keisuke?Kimura 《Colloid and polymer science》2004,283(1):1-9
Macroscopic and microscopic dissipative structural patterns are formed in the course of drying a suspension of Chinese black ink on a cover glass and in a dish. The time for the drying and the pattern area increased as the particle concentration increased. The broad ring patterns of the hills accumulated with the particles formed around the outside edges on a macroscopic scale. The height and the width of the broad ring increased as the particle concentration increased. The spokelike patterns of the rims accumulated with particles were also formed on a macroscopic scale. Microscopic patterns of colloidal accumulation were observed over the whole region of the pattern area. Various types of convection cells were observed on a cover glass and in a dish at 25–80 °C. A time-resolved observation of the drying process was also made. The convections of water and the colloidal particles at different rates under gravity and the translational and rotational Brownian movement of the particles were important for the macroscopic pattern formation. Microscopic patterns were determined by the translational Brownian diffusion of the particles and the electrostatic and the hydrophobic interactions between the particles and/or between the particles and the cell wall in the course of the solidification of the particles. 相似文献
90.
Ito K Takayama Y Ikedo M Mori M Taoda H Xu Q Hu W Sunahara H Hayashi T Sato S Hirokawa T Tanaka K 《Journal of chromatography. A》2004,1039(1-2):141-145
The determination of seven aliphatic carboxylic acids, formic, acetic, propionic, isobutyric, n-butyric, isovaleric and n-valeric acids in anaerobic digestion process waters was examined using ion-exclusion chromatography with conductimetric detection. The analysis of these biologically important carboxylic acids is necessary as a measure for evaluating and controlling the process. The ion-exclusion chromatography system employed consisted of polymethacrylate-based weakly acidic cation-exchange resin columns (TSKgel OApak-A or TSKgel Super IC-A/C). weakly acidic eluent (benzoic acid), and conductimetric detection. Particle size and cation-exchange capacity were 5 microm and 0.1 meq./ml for TSKgel OApak-A and 3 microm and 0.2 meq./ml for TSKgel Super IC-A/C, respectively. A dilute eluent (1.0-2.0 mM) of benzoic acid was effective for the high resolution and highly conductimetric detection of the carboxylic acids. The good separation of isobutyric and n-butyric acids was performed using the TSKgel Super IC-A/C column (150 mm x 6.0 mm i.d. x 2). The simple and good chromatograms were obtained by the optimized ion-exclusion chromatography conditions for real samples from mesophilic anaerobic digestors, thus the aliphatic carboxylic acids were successfully determined without any interferences. 相似文献