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  • Wiley-Blackwell  (7)
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  • 1
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 3 (1981), S. 126-133 
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Wetting nitrogen plasma modified polyethylene with a permeable solvent rapidly reduces the surface concentration of amines originally incorporated with plasma exposure. The rate of decrease in surface amine concentration increases with increasing hydrogen bonding capabilities of the solvent. A slower decrease in the surface amine concentration occurs for dry, modified polymers not wet with a solvent. A model consistent with a solvent mediated dilution of surface groups into the interior of the polymer is proposed. Upon protonation with aqueous H3PO4 or H2SO4, subsurface amines readily migrate back to the surface; HCl and HNO3 do not produce this result. The rate of concentration of protonated amines into the ESCA sampling depth is dependent on the permeability of the aqueous acid and the solubility of the corresponding protonated ammonium salt in polyethylene. The mobility of surface functional groups seriously affects the use of chemical derivatization reagents for the ESCA of modified polymer surfaces and raises important questions concerning the significance of a polymer surface analysis. The reaction of surface amines with pentafluorobenzaldehyde is used to illustrate this point.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 991-1019 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Surfaces of polymers [polyethylene, polystyrene, poly(ethylene terephthalate), poly(oxymethylene), cellulose acetate, polyacrylonitrile, nylon 6, and polytetrafluoroethylene] treated with argon (inert) and nitrogen (reactive) plasma were examined by ESCA (electron spectroscopy for chemical analysis). Argon plasma treatment generally introduces oxygen functionalities into the polymer surface. Nitrogen treatment generally incorporates nitrogen and oxygen functionalities into the treated surface. The extent of oxygen incorporation is typically less than that produced by argon plasma. When nitrogen and oxygen functional groups are already in a polymer structure, the extent of additional incorporation of these two elements as a result of plasma treatment is very much less than with other polymers. Polymers which contain only one of the elements tend to incorporate the other element to much the same degree as polymers without either element initially present.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 415-425 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Plasma polymerizations of ethylene and tetrafluoroethylene are compared. In the plasma polymerization of ethylene and of tetrafluoroethylene, glow characteristics play an important role. Glow characteristic is dependent on a combined factor of W/Fm, where W is discharge power and Fm is monomer flow rate. At higher flow rates, higher wattages are required to maintain “full glow.” In the plasma polymerization of tetrafluoroethylene, simultaneous decomposition of the monomer competes with plasma polymerization. Above a certain value of W/Fm, decomposition becomes the predominant reaction, and the polymer deposition rate decreases with increasing discharge power. ESCA results indicate that the plasma polymer of tetrafluoroethylene that is formed in an incomplete glow region (low W/Fm) is a hybrid of polymers of plasma polymerization and of plasma-induced polymerization of the monomer. Polymers formed under conditions of high W/Fm to produce “full glow” are similar, regardless of the extent of decomposition of the monomer. They contain carbons with different numbers of F(CF3, —CF2—, 〉CF—, 〉C〈) and carbons bonded to other more electronegative substituents.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 20 (1976), S. 543-555 
    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: Preparation of composite membranes by plasma polymerization is affected not only by the type of monomer and the mode of discharge but also by the interaction of plasma-polymer substrate. Consequently, the reverse osmosis characteristics of composite membranes are dependent on the combination of substrate and monomer(s). The interactions of plasma and polymer are investigated using porous polysulfone film and cellulose nitrate-cellulose acetate (CNCA) porous film as the substrates, and acetylene/H2O/N2 and acetylene/H2O/CO as the monomer systems. The effects of plasma pretreatment of the substrates on the chlorine resistance of the membranes are also investigated.
    Additional Material: 10 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 1003-1011 
    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 plasma polymerization of tetrafluoroethylene in an inductively coupled radio frequency glow discharge, using a flow system, was studied. A simple long tube reactor, with the coupling coil placed at the middle of the tube and gas entrance and exit at the respective ends, was used. Deposition rates and the chemical nature of the polymer (as revealed by ESCA spectra and surface energy studies) are obtained as a function of location in the reactor tube with respect to the coupling coil and of applied energy per unit mass of tetrafluoroethylene (W/FM). It was found that a fluorinepoor polymer, containing considerable carbon-oxygen bonds (after contact with air), is obtained at all locations at high W/FM. When a low W/FM is utilized, such a fluorine-poor polymer is also obtained at locations downstream from the coupling coil (the location of the highest energy density) in the reactor. In the latter case a fluorine-rich polymer containing very little oxygen is formed upstream from the coil. The polymer deposition rate distribution is also considerably broader in a high W/FM plasma than when low W/FM is used. These results are in agreement with earlier studies indicating that fluorine abstraction and decomposition due to fluorine etching occur when the energy density, as expressed by W/FM, is high.
    Additional Material: 5 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 3471-3488 
    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 plasma polymerization of tetrafluoroethylene (TFE) is studied in a capacitively coupled system with internal electrodes using a 10 kHz (af) and a 60 Hz (ac) source. The emphasis is on identifying conditions that are compatible with continuous coating of plasma polymer on a substrate moving through the center of the interelectrode gap. Operation at a pressure below 100 mTorr is most favorable for deposition of a substantial portion of the plasma polymer on this substrate. Plasma polymer deposited in this way is characterized by ESCA and by deposition rate data and compared to that deposited using rf power in both capacitively and inductively coupled systems. The polymers found in all systems are broadly similar and completely different from conventional poly(TFE). The distribution of power density in the various systems has been identified and compared. This is accomplished by using the known susceptibility of fluorine-containing polymers (including plasma polymer) to a high-power plasma as a probe of plasma power density within the interelectrode gap in the capacitively coupled system. The most active zone of the af or ac plasma is close to the electrode at a plasma pressure of approximately 40 mTorr. The use of a magnetic field leads to an intense localized glow such that etching by active fluorine atoms occurs at a specific locus on the electrode. By contrast, the low-pressure rf capacitively coupled glow discharge is the mildest of those investigated, and its most active zone is further from the electrode and much more diffusely localized by a magnetic field.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 3449-3470 
    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 plasma polymerization of tetrafluoroethylene (TFE) is studied in a capacitively coupled system with internal electrodes using radio frequency (13.56 MHz) power. The emphasis is on identifying conditions that are compatible with continuous coating of plasma polymer on a substrate moving through the center of the interelectrode gap. At high pressure (500 mTorr), deposition of plasma polymer is primarily on the electrodes rather than on a substrate placed midway between electrodes. Glow is observed in only part of the interelectrode gap at low powers and fills the gap only at high power levels. The use of a magnetic field effects barely discernible changes. Low-pressure (below 100 mTorr) operation is more favorable for deposition of a substantial portion of the plasma polymer on a substrate placed midway between electrodes. The plasma polymer deposited at low pressure is characterized by ESCA and deposition rate data and compared to that deposited in an inductively coupled system. The polymers formed in both systems are broadly similar and completely different from conventional poly(TFE). Subtle system-dependent differences are identified. The known susceptibility of fluorine-containing polymers (including plasma polymer) to a high-power plasma has been used as a probe of plasma power density within the interelectrode gap in the capacitively coupled system. Without magnets the most active zone of the plasma is in the center of the interelectrode gap. The use of a magnetic field moves this active zone closer to the electrodes and leads to a more efficient coupling of energy to a polymerizing glow discharge.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
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