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Volume 18 (1993)
- Issue 6 Pages 318-
- Issue 5 Pages 264-
- Issue 4 Pages 196-
- Issue 3 Pages 132-
- Issue 2 Pages 69-
- Issue 1 Pages 3-
Volume 18, Issue 4
Displaying 1-7 of 7 articles from this issue
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K. Nakamura, Y. Iwasaki, T. Nakashima1993 Volume 18 Issue 4 Pages 196-206
Published: July 01, 1993
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSProperties and applications of porous glass materials prepared by phase separation are reviewed. New porous glass, SPG (Shirasu porous glass) from SiO2-Al2O3-B2O3-CaO glass and conventional Vycor type from SiO2-B2O3-Na2O glass are more representative materials from the point of applications among several types of porous glass.
Pore size range were largely extented from 4-40nm of Vycor type to 4-20, μm by the development of SPG. Both types have the narrowest pore size distribution among all kinds of porous materials. The microstructure of porous glass with cylindrical and interconnected countless pores are very uniformly controlled through each element. The porous glass membranes are resistant to high temperature, acids, organic solvents and microbes. Surface treatment by chemical reagents is possible to change surface properties. The mechanical strength is enough for applications to membrane technology. SPG is superior to alumina and zirconia having the same level of porosity especially in compressive strength.
The porous glass can be prepared into shapes of tubes, flat sheets or powder.
Membrane emulsification is a new technology to produce single emulsion (Oil in Water, W/O) with uniformly controlled particle size and also to produce double emulsion (O/W/O, W/O/W) with high yield. A large scale application was achieved already with the membrane emulsification using SPG.
Membrane separation, bubbling element for efficiently dissolving gas into liquid, carrier for HPLC analysis and DNA synthesis are also newly developed applications for the porous glass materials.View full abstractDownload PDF (2141K) -
Chien-Yuan Chen, Isao Karube1993 Volume 18 Issue 4 Pages 207-219
Published: July 01, 1993
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSBiocompatibility is indispensable to biosensors for in vivo purpose. To those for in vitro applications biocompatibility can also promote their stability and life time. 2-Methacryloyloxyethyl phosphorylcholine, abbreviated as MPC, is an inert biocompatible material. Biocompatible membranes with special functions including diffusion-limiting effect, selective permeability, and the capability of immobilizing enzymes were obtainable by the copolymerization of MPC with other monomers. These membranes were applied to fabricate needle-type glucose sensors. The sensors were conferred with a wide workable range, good biocompatibility, remarkable long-term stability, and the ability of curtailing interfering responses upon application of these specially functionalized biocompatible membranes.View full abstractDownload PDF (2177K) -
Mamoru Iso1993 Volume 18 Issue 4 Pages 220-227
Published: July 01, 1993
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThis paper deals with preparation and application of microcapsules containing enzymes. Microencapsulation of enzymes has a number of advantages over other immobilization methods. Within the microcapsules, the enzymes are kept in the same soluble form as the native ones, and the substrates are allowed to react with them without steric restriction. The membrane of microcapsules prevents the immobilized enzymes from the destruction by endogenous enzymes, the immune reaction and the inactivation under physiological conditions.
At present, enzymes may be microencapsulated by (a) phase separation method, (b) liquid drying method, (c) interfacial polymerization method. According to the objectives and conditions of the application, the most suitable method is selected out of three methods. Commercial applications of bioreactors employng immobilized enzymes draw a wide attention as a effective production of bioactive materials, and the microencapsulated enzymes have also vast potential in pharmaceutical and biomedical use. Furthermore, multienzyme systems would be desirable for more widespread applications. For immobilization of the multienzymes, microencapsulation has a number of advantages not shared by other methods.View full abstractDownload PDF (1204K) -
Takeo Yamaguchi1993 Volume 18 Issue 4 Pages 228-236
Published: July 01, 1993
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSMuch attention has been paid to pervaporation for separating organic liquid mixtures instead of distillation. Many pervaporation processes have now been commercialized for separation of water from concentrated organic liquids. Almost no commercial pervaporation process has been developed for the organic/organic separation, although this process has a large application potential. However, many types of membranes for organic liquid separation have been prepared in a number of laboratories. In the present paper, recent developments of pervaporation membranes are reviewed.View full abstractDownload PDF (1307K) -
Toshinori Kojima, Shigekazu Yagi, Kazue Motojima, Kazuhiro Nishijima, ...1993 Volume 18 Issue 4 Pages 237-247
Published: July 01, 1993
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSPermeation rates of L-methionine and acethyl-DL-methionine were measured through ion exchange membranes into sodium chloride solution, assuming that the former was produced from the latter using a immobilized enzyme reactor. Both were permeated through an anion exchange membrane. L-methionine was selectively recovered from a L-methionine and acethyl-DL-methionine mixture by Donnan dialysis using a cation exchange membrane under the various pH conditions, however its rate was smaller than that through anion exchange membrane.
At low pH, the permeation of hydrogen ion was dominant while that of L-methionine was suppressed. The flux of L-methionine attained to a maximum at pH 2 and decreased with increasing pH. Its mechanism was discussed based on ion exchange equilibrium at the interface and mass transfer in the boundary layer and membrane.View full abstractDownload PDF (1166K) -
H. Yanagishita, D. Kitamoto, T. Nakane1993 Volume 18 Issue 4 Pages 248-253
Published: July 01, 1993
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSThe effect of annealing of polyimide membrane was investigated to improve the solvent-resistance and separation performance using an asymmetric ultrafiltration membrane which was prepared by the phase inversion process. It was concluded that dioctyl sebacate was the best solvent for annealing of the polyimide membrane, and that the best annealing condition was at 200-250°C for 3 hours. The membrane which were annealed at 250°C for 3 hours showed the highly solvent-resistance.View full abstractDownload PDF (1243K) -
Masaru KURIHARA1993 Volume 18 Issue 4 Pages 254-257
Published: July 01, 1993
Released on J-STAGE: March 04, 2011
JOURNAL FREE ACCESSAn ultrafiltration membrane, prepared from specially polymerized polyacrylonitrile with high molecular weight, has been developed by Toray Industries, Inc. This new membrane and its modules are designed specially for reducing membrane fouling.View full abstractDownload PDF (1036K)
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