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771.
Chika Takai Tadashi Hotta Shuji Shiozaki Shuhei Matsumoto Takehisa Fukui 《Colloids and surfaces. A, Physicochemical and engineering aspects》2011,373(1-3):152-157
A solid-in-oil-in-water (S/O/W) emulsion system has been developed to prepare porous polymeric microspheres. The obtained microspheres showed unique core–shell structure with a dense core and a surface porous layer. The emulsion system has two processes. In the first process, S/O/W1 viscous emulsion is prepared by dropping of S/O phase in the first water phase (W1). In the second process, the S/O/W1 emulsion is poured to another water phase (W2) as S/O/W1/W2 emulsion. During the process, S/O/W1 droplet becomes microsphere after organic medium completely diffusion. Emulsion techniques have various effective combinations such as additive and process conditions to design microsphere morphology. With regards to the proposed S/O/W system, addition of the solid phase in the system is a key factor to form the porous structure. When the medium diffusion starts, the solid makes W1 phase kept inside the S/O/W1 droplet. The remained W1 phase changes surface porous layer after purification. Affinity between the solid and oil phase should be adjusted as well. In this study, an optimization of the emulsion system was attempted considering solubility parameter and polarity. Additionally, it is found that process conditions could help to design microsphere morphology such as pore size and porous layer thickness. 相似文献
772.
Wataru Ninomiya Yasuhiko Tanabe Ken-Ichiro Sotowa Toshiya Yasukawa Shigeru Sugiyama 《Research on Chemical Intermediates》2008,34(8-9):663-668
Dehydrogenation of decalin to naphthalene through tetralin and that of dicyclohexyl to biphenyl through phenylcyclohexane with Pt/C and Pd/C was investigated mainly under the liquid film state, in which the catalyst was just wet but not suspended and covered with a thin film of liquid substrate. To improve the catalytic activities, the effects of the addition of tellurium into Pd/C were investigated to reveal that the combination of tellurium, palladium and conjugated systems produced during the dehydrogenation of cycloalkames was important to the improvement of the activities. 相似文献
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Nanosized zinc oxide (ZnO) particles were prepared in an amphiphilic N,N-dimethylacrylamide (DMAA) gel composed of a three-dimensional network with an effective pore size of the order of nanometers.
The procedures consist of two major steps: (1) preparation of a precursor and (2) hydrolysis of the precursor to form nanoparticles.
First, the plate-type dry gel was swollen in ethanol containing zinc acetate (ZnAc) in order to diffuse ZnAc molecules into
the gel. Then, the ethanolic solution containing the gel was heated to ∼80°C to prepare the precursor. In the hydrolysis of
the precursor, lithium hydroxide was added as the catalyst to the precursor solution containing the gel, and the solution
was placed in an ultrasonic bath. Although the DMAA gel containing ZnO particles was completely transparent, it exhibited
a yellow-green luminescence when irradiated with UV light. The ZnO nanoparticles stably dispersed in the gel network without
growing, aggregating, or flowing out for over several months at a relatively high temperature of 50°C. The particle size depended
on the effective pore size of the gel network, which could be controlled by the synthesis composition of the gel, that is,
by the concentrations of DMAA as the primary monomer and N,N′-methylenebisacrylamide (MBAA) as the cross-linker used for synthesizing the gel. This implies that the particle size can
be controlled at the nanosized level by the synthesis composition of the gel. 相似文献
775.
Shuji Yoshikawa 《Mathematical Methods in the Applied Sciences》2005,28(12):1423-1443
We show the unique global existence of energy class solutions for the Falk model system of shape memory alloys under the general non‐linearity as well as considered in Aiki (Math. Meth. Appl. Sci. 2000; 23 : 299). Our main tools of the proofs are the Strichartz type estimate for the Boussinesq type equation and the maximal regularity estimate for the heat equation. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
776.
Shuji Akai Kouichi Tanimoto Yasuyuki Kita 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2004,116(11):1431-1434
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