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Volume 46, Issue 12
Displaying 1-14 of 14 articles from this issue
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Chuan Xin Liang, Kiyoshi Hirabayashi1990 Volume 46 Issue 12 Pages 535-540
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe mechanical properties and the water content of silk fibroin membranes were improved by adding the optimum amounts of fibroin fibers and Poly (sodium glutamate) (PSG). The mixing was carried out in the regenerated fibroin solution. The water content of membrane increased with increasing the amount of PSG. The rupture strength decreased with increasing the water content, however, the relationship between the elongation at rupture and the water content showed the maximum for the PSG-added membrane and the membrane containing both PSG and fibroin fiber.View full abstractDownload PDF (425K) -
Kazuhiro Tanaka, Hidetoshi Kita, Ken-ichi Okamoto1990 Volume 46 Issue 12 Pages 541-547
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSPermeability, solubility and diffusion coefficients [P, S, and _??_ (=P/S)] of gases were measured at 35°C and 10 atm for a series of polyimides prepared from four acid dianhydrides and three diamines. The introduction of CF3 groups decreased the packing density of polymer segments, resulting in a small increase in S and large increases in _??_ and P. A roughly linear relationship was observed between In _??_CO2 and the inverse of the fraction of “free space” (or expansion volume). The diffusivity selectivity was significantly different among the polyimides, while the solubility selectivity changed only slightly. For the CO2/CH4 system, polyimides having lower local segmental mobility tended to have higher diffusivity selectivity. The introduction of -C(CF3)2- linkages and/or CF3 substituent groups was effective for CO2/CH4 and O2/N2 separations, but not for H2/CO and H2/CH4 separations, because in the latter cases a moderate increase in PH2 was followed by significant decreases in PH2/PCO and PH2/PCH4.View full abstractDownload PDF (509K) -
Shoji Takigami, Toshio Yamada, Yoichi Mizuno, Yoshio Nakamura1990 Volume 46 Issue 12 Pages 548-555
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDiffusive and hydraulic permeabilities of water through nylon 6 (GN) membranes grafted with acrylic acid (AA), acrylamide (AM), and p-styrenesulfonic acid (SS) were investigated. The diffusion coefficient of D2O (D) through each kind of GN membrane increased with increasing the volume fraction of water (H) in swollen membrane. It was found that the free volume theory of diffusion is applicable to the diffusion of D2O through the GN membranes with high H. However, In D gradually decreased with increasing (1/H)-1 in different ways for AA- and AM-GN membranes at low H region with less than 0.5. The state of sorbed water may contribute to the diffusion of water in the GN membrane with low H. On the other hand, close relationships were observed between the hydraulic permeability coefficient (K) of water and H. Water permeates through the membrane with low H mainly by diffusion even under a hydraulic pressure gradient, and water transport is predominantly due to the viscous flow in the region of high H.View full abstractDownload PDF (535K) -
Masayasu Tasaka, Hisashi Hirai, Ryotaro Kiyono1990 Volume 46 Issue 12 Pages 556-560
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSElectrochemical analysis is considered to be applicable to the transport phenomena across a membrane which accompanies ionic reactions in the system where two solutions on both sides of the membrane are acidic and basic, respectively. Transport of halide ions across poly (vinylpyridine-co-styrene) membranes was analyzed by measuring the time dependence of the membrane resistance and bi-ionic potential. As a result, it becomes clear that poly (2-vinylpyridine-co-styrene) membranes are permselective for Cl- because HCl forms more easily pyridinium salt than HBr, and also that poly (4-vinylpyridine-co-styrene) membranes are permselective for Br- because the mobility of Br- is higher than that of Cl- in the membranes.View full abstractDownload PDF (338K) -
Iwane Fujii, Takeshi Imada, Kazuo Tsuchiya, Akon Higuchi1990 Volume 46 Issue 12 Pages 561-567
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDehydration of CaCl2-LiCl solution was performed by membrane distillation as a part of thermochemical heat pump. Water molecules in the membrane distillation permeate through the porous membrane, diffuse in the diffusion gap and are condensed finally on the cooling plate. The resistance of water permeation in the membrane distillation is, therefore, considered to be two steps, i.e., permeation through porous membrane and permeation in the diffusion gap. Membrane distillation for 10-40 wt% of CaCl2-LiCl was tested at various temperature differences and different pressure in a diffusion gap (pD). Effect of pD on water permeabilities is discussed. It is suggested that the resistance of water permeation is relatively low in the diffusion gap and that the resistance mainly occurs in water permeation through the porous membrane.View full abstractDownload PDF (455K) -
Keishin Mizoguchi, Katsuhiko Terada, Yasutoshi Naito, Takuji Hirose, Y ...1990 Volume 46 Issue 12 Pages 568-574
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe origin of the error in the measurement of small diffusional time-lags (θ) was studied by use of an aluminum foil with an orifice in place of a polymer membrane. The error was caused by the flow of the low-concentration gas, i.e., the pressure gradient in the downstream side. Based on the result, a new apparatus for the measurement of small θ was developed, in which a high-response transducer was directly attached to the membrane to monitor the pressure of the downstream side. A microcomputer was used for the on-line measurement of the pressure and the data analysis. The performance of this new system was tested for low density polyethylene and silicone rubber samples with various thicknesses. By this system, θ as small as ca. 0.2s could be measured. The errors in the measurement of small θ due to the structure of the downstream side of the permeation cell and the setting up of the start time in the time-lag measurement are also discussed.View full abstractDownload PDF (532K) -
Toshihiro Hirotsu1990 Volume 46 Issue 12 Pages 575-579
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESS2-Hydroxyethyl acrylate and 2-hydroxyethyl methacrylate were graft-polymerized onto plasma-pretreated porous polypropylene films, and their water-ethanol separation characteristics were investigated by pervaporation method. These composite membranes were hydrophilic, and water-permseparation was achieved. The results were compared to those obtained with the membranes grafted with 2-methoxy-ethyl acrylate and 2-methoxyethyl methacrylate for elucidating the effects of hydroxyl group on water-permselectivity. When the performance was compared by the relationship of separation factor and flux, the better pervaporation characteristics were observed generally in the hydroxyl group containing membranes. The properties were attributed to the higher adsorption of water through hydroxyl group in the grafted membranes.View full abstractDownload PDF (314K) -
KENZO SHIMAHARA1990 Volume 46 Issue 12 Pages P547-P552
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
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KENSUKE SAKURAI1990 Volume 46 Issue 12 Pages P553-P557
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
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SEI-ICHI AIBA1990 Volume 46 Issue 12 Pages P558-P563
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
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HIROSHI SEO1990 Volume 46 Issue 12 Pages P564-P569
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
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SHIGETOSHI AMIYA, AKIRA MOCHIIZUKI, SHUZO YAMASHITA1990 Volume 46 Issue 12 Pages P570-P575
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
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TOSHIAKI SHIOYA1990 Volume 46 Issue 12 Pages P576-P580
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
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DAIZO KOGA1990 Volume 46 Issue 12 Pages P581-P585
Published: December 10, 1990
Released on J-STAGE: November 28, 2008
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