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  • 1
    Electronic Resource
    Electronic Resource
    The states of water in gel cellophane membranes (1984)
    Springer
    Polymer bulletin 11 (1984), S. 203-208 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The states of water in gel cellophane membranes were investigated by DSC measurements. An extra exothermic peak, which has not previously been reported, was observed at heating rates slower than 2.5K/min. The peak was ascribed to the crystallization of the liquid water in the heating process. The ratio of the nonfreezing water (often referred to as bound water) (g) to the dry membrane (g) was estimated to be 1.06. This value is far larger than the bound water contents reported for cellulose acetate membranes (Frommer et al. 1972, Taniguchi et al. 1975).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00258031
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  • 2
    Electronic Resource
    Electronic Resource
    Production of interferon-β in a culture of fibroblast cells on some polymeric films (2000)
    Springer
    Cytotechnology 34 (2000), S. 165-173 
    Details
    ISSN: 1573-0778
    Keywords: cell culture ; enhanced production ; fibroblast cells ; interferon-β ; Langmuir-Blodgett film
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Normal human skin (NB1-RGB) cells were cultured in the presenceof polyinosinic and polycytidylic acids, diethylaminoethyldextran, cycloheximide and actinomycin D, which induced humaninterferon-β. The simplest induction method, that requiredonly polyinosinic and polycytidylic acids and diethylaminoethyldextran was found to give the highest production ofinterferon-β by the cells. The cell growth and productionof interferon-β were investigated for NB1-RGB cellscultured on silk fibroin, poly(γ-methyl-L-glutamate),poly(γ-benzyl-L-glutamate) and collagen films prepared bythe Langmuir-Blodgett (LB) and casting methods. The cell densityof NB1-RGB cells cultured on the LB films was found to be higherthan that on the cast films made of the same polymer. Thisindicates that not only the chemical structure of the polymersused for the preparation of the films but the preparationmethods of the films, i.e., casting and LB methods, are also astrong factor affecting the cell growth. The production ofinterferon-β per unit number of cells was found to behigher on the cast films than that on the LB films made of thesame polymer. This is explained by the fact that the optimalsuppressed growth of NB1-RGB cells on the cast films leads tothe enhanced production of interferon-β on the cast filmscompared to those on the LB films prepared by the same polymer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008130223190
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  • 3
    Electronic Resource
    Electronic Resource
    Enhanced CEA production associated with aspirin in a culture of CW-2 cells on some polymeric films (1999)
    Springer
    Cytotechnology 31 (1999), S. 233-242 
    Details
    ISSN: 1573-0778
    Keywords: cell culture ; carcinoembryonic antigen ; aspirin ; enhanced production ; Langmuir-Blodgett film
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Human colorectal adenocarcinoma tumor (CW2) cells were cultivated in RPMI 1640 media containing 0–7.5 mM aspirin and 10% fetal bovine serum for the production of carcinoembryonic antigen (CEA). By adding aspirin to the media, the production of CEA per cell increased by up to one hundred fold compared to cultivation in normal media containing no aspirin, even though the total cell concentration decreased with the increase in aspirin in the media. The production of CEA was also investigated for CW2 cells cultured on silk fibroin, poly(γ-benzyl-L-glutamate) and poly(γ-benzyl-L-glutamate)/poly(ethylene oxide) diblock copolymer films prepared by the Langmuir-Blodgett and casting methods. The highest production of CEA per cell was observed for the CW2 cells on poly(γ-benzyl-L-glutamate) and its diblock copolymer films prepared by the Langmuir-Blodgett method in the medium containing 5 mM aspirin after 168 hr of inoculation. This originates from the fact that the cell density on the films in the medium containing 5 mM aspirin was the lowest under these conditions. It is suggested that CW2 cells produce CEA more effectively when the cell growth is suppressed by addition of toxic chemicals such as aspirin or by culture on unfavorable films for cell growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008030730814
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  • 4
    Electronic Resource
    Electronic Resource
    Infrared spectroscopic studies of CO2 sorbed in glassy and rubbery polymeric membranes (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 32 (1994), S. 149-157 
    Details
    ISSN: 0887-6266
    Keywords: membrane ; dual-mode sorption ; infrared spectroscopy ; carbon dioxide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Infrared spectra of CO2 sorbed in rubbery and glassy polymers were measured to examine the relationships between the spectroscopic data and physical properties of the polymeric membranes. The “V-shape” tendency in the plot of W1 [i.e., half-width of CO2 peak sorbed in the membranes] vs glass-transition temperature (Tg) is observed, and has exactly the same tendency that is widely known from the plot of log D (diffusion coefficient) vs Tg. It is suggested that the membranes having a wider W1 give a faster diffusion coefficient, since W1 is inversely related to the moment of inertia of CO2 in the membranes. Two distinct peaks of CO2 were not observed in the infrared spectra of CO2 sorbed in the glassy polymers. This suggests that the states of CO2 in the Henry mode and Langmuir mode in the glassy polymers are similar in the spectroscopic measurements. © 1994 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1994.090320118
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  • 5
    Electronic Resource
    Electronic Resource
    Effect of ultraviolet light irradiation on gas permeability in polyimide membranes. 1. Irradiation with low pressure mercury lamp on photosensitive and nonphotosensitive membranes (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 2259-2269 
    Details
    ISSN: 0887-6266
    Keywords: polyimide membrane ; ultraviolet light irradiation ; crosslinking ; physical changes ; gas permeability ; sorption property ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Two types of polyimide membranes; one crosslinkable and the other noncrosslinkable using ultraviolet light irradiation (UV irradiation), were prepared and investigated concerning the effect of UV irradiation on their gas permeabilities and selectivities. Permeability and diffusion coefficients for O2, N2, H2, and CO2 were determined using the vacuum pressure and time lag method. Sorption properties for carbon dioxide were carried out to evaluate the changes in the free volume in the membranes due to the irradiation. In both membranes, permeability coefficients for all gases used in this study decreased and permselectivity, particularly for H2 over N2, increased with increasing UV irradiation time without a significant decrease in the flux of H2. The coefficients depended on the membrane thickness, suggesting asymmetrical changes in both membranes due to UV irradiation. It was suggested by an attenuated total reflection (ATR) FTIR method and analysis of the gas sorption properties of the membranes that the physical changes due to UV irradiation at the irradiated side in both membranes significantly affected their gas permeation properties compared with the chemical changes, especially the crosslinking in the crosslinkable type. © 1997 John Wiley & Sons, Inc. J. Polym Sci B: Polym Phys 35: 2259-2269, 1997
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Membrane potentials and permeation of NaCl in poly(vinyl alcohol-co-itaconic acid) membranes (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 31 (1986), S. 419-428 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The membrane potential and permeability of NaCl were measured for six crosslinked poly(vinyl alcohol-co-itaconic acid) membranes having various water contents [0.25≤H≤0.83 H2O (g)/swollen membrane (g)] and interpreted by means of an equation derived from Schlögl′s theory. Both results of the membrane potential and the permeability of the membranes having H≥0.34 could be satisfactorily interpreted by the theory. The permeability of NaCl in the membrane of H=0.25 gave, however, an increasing tendency with the decrease of the upstream concentration lower than 0.04 mol/L. It was considered that the concentration dependence reverse to what was caused by the Donnan exclusion might be due to the concentration dependence of the thermodynamic partition coefficient in nonfreezing water of the membrane. By the equation thus derived the membrane potential and the permeability of NaCl in the membrane of H=0.25 were expained qualitatively. The mobility ratios of Na+ and Cl- and the effective charge density in the membranes were discussed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1986.070310210
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  • 7
    Electronic Resource
    Electronic Resource
    Surface-modified polysulfone hollow fibers (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 36 (1988), S. 1753-1767 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Controlled reactions on the inner side, outer side, and both sides of the surfaces of polysulfone ultrafiltration hollow fibers with propane sultone and Friedel-Crafts catalysts were developed. EPMA measurements and MTR spectra for the chemically modified fibers suggested existence of —CH2CH2CH2SO3- segments on the modified surfaces. The modified fibers were found to have smaller molecular weight cut-off than nonmodified fibers, and the fibers modified on the internal surfaces gave better rejection of polyethylene glycol 6000 than those modified on the external surfaces, although the fibers that reacted with solution of the propane sultone and SnCl4 at 70°C and 80°C showed negative rejection of the polyethylene gylcol. Absorption of polyethylene glycol on the modified fibers is estimated to be less than the nonmodified fibers from the flux ratios of aqueous polyethylene glycol solution to pure water. This effect is attributed to the heparinlike active group of modified segments.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070360804
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  • 8
    Electronic Resource
    Electronic Resource
    Permselectivities through artificial membranes at a non-steady state (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 2181-2190 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Non-steady-state flux ratios of oxygen to nitrogen in a poly(dimethyl siloxane) membrane are theoretically investigated as a function of time. Concentration profiles of oxygen and nitrogen are found to decay to a negligible concentration with an increase of the distance from membrane surface and it is observed that oxygen penetrates deeper than nitrogen in the membrane at the non-steady state. Differences of concentration profiles of oxygen and nitrogen lead to enormously high selectivity for oxygen at the non-steady state. The flux and selectives are studied under the condition that the upstream pressure is pulsating to keep the non-steady state continuously as suggested by Paul[Ind. Eng. Chem. Proc. Des. Dev., 10, 375 (1971)]. Model calculations are also performed for the concentration of uranium 235 from natural uranium. The flux ratio of uranium 235 to uranium 238 in the non-steady state is calculated to be 1.144 at time/L2 = 800 s/cm2 (L = membrane thickness), which is higher than the value, 1.00429, at a steady state.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070370810
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  • 9
    Electronic Resource
    Electronic Resource
    Permeation of solutes in water-swollen poly(vinyl alcohol-co-itaconic acid) membranes (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 32 (1986), S. 3229-3237 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Partition and permeability coefficients of urea, NaCl, and saccharose in water-swollen poly(vinyl alcohol-co-itaconic acid) membranes with various water contents (0.25 ≤ H ≤ 0.86) were measured. Partition coefficients and permeability ratios in freezing and nonfreezing water were estimated based on a parallel permeation model. It was suggested that at 25°C the permeation of saccharose in the nonfreezing water was nearly zero due to its negligible partition coefficient, while NaCl and urea were found to be able to permeate even the nonfreezing water. The activation energies of diffusion for three solutes were found to increase with the decrease of water content of the membranes. Since the fraction of nonfreezing water increased with the decrease of water content of the membranes, it is assumed that the increased activation energy of diffusion is due to the fact that the diffusion in nonfreezing water needs higher activation energy than in the pure bulk water.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1986.070320126
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  • 10
    Electronic Resource
    Electronic Resource
    Surface modified polysulfone hollow fibers. III. Fibers having a hydroxide group (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 41 (1990), S. 1973-1979 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Polysulfone ultrafiltration hollow fibers were chemically modified on the surfaces with propylene oxide and Friedel-Crafts catalysts. A peak at 1.6 ppm was observed in H1-NMR spectrum of the modified fibers at 45°C, while the peak was not observed at 27°C measurements. The peak was attributed to a hydroxide group from the peak shift at high temperature. Micro ATR spectra of the modified fibers also suggested existence of CH(CH3)CH2OH segments on those surfaces. The modified fibers showed 10-80% rejection of polyethylene glycol 6000 at feed concentration of 0.5 wt %, depending on the conditions of surface reaction, and were found to have smaller molecular cut-off than nonmodified fibers. The fibers were also compared with modified fibers with propane sultone reported previously [A. Higuchi et al., J. Appl. Polym. Sci., 36, 1753 (1988)], which had negatively charged segments of CH2CH2CH2SO3-. Absorption of bovine serum albumin on the modified fibers was estimated to be less than the nonmodified fibers from permeation measurements. It is suggested that fibers having hydrophilic surfaces show better results of anti-absorption of solutes than the nonmodified fibers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1990.070410904
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