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  • 1
    ISSN: 1572-8978
    Keywords: DC plasma polymerization ; monomers hexamethylidisiloxane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract This paper investigates DC plasma polymerization kinetics by combining plasma parameters with film deposition rate in different conditions. The monomers hexamethyldisiloxane (HMDSO) and pyrrole were used. Both single and double Langmuir probes were used to measure the plasma parameters in pulsed power and continuous discharges. In order to avoid probe tip contamination, the probe was heated. Plasma density and electron temperature are reported. The electron current wave form is obtained in pulse power conditions. From the data, a plasma polymerization model is proposed. The conclusion is that the monomer molecules and free radicals adsorbed on the substrate surface react with activated sites produced by high energy ions bombarding the film, resulting in polymerization at the film surface.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A number of simple aliphatic hydrocarbon polymers have been studied by static SIMS. The low-mass positive spectra reflect structural differences in the polymeric structure, which result in characteristic fingerprint spectra. Unsaturation and differences in branching lead to very distinct spectral features which show promise for the application of SIMS as an analytical technique in polymer-related areas. An attempt is made to interpret the spectra in terms of molecular structure, fragmentation mechanisms and ion stabilities. The chemical nature of ion beam damage in PE and PP was studied to some extent.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The applicability of Time-of-Flight SIMS (TOFSIMS) to the study of adhesion phenomena is discussed. The technique is especially powerful for the study of interactions at polymer-metal interfaces. This is demonstrated by a number of examples of TOFSIMS analysis of polymer surfaces, metal pretreatments and paint-metal interfaces of materials used in the automotive industry. The TOFSIMS high-resolution spectrum of a film of Nylon-6® is interpreted in some detail. The metal pretreatments that are discussed are by functional silanes. Thin organic films deposited on metals by plasma polymerization of silanes have also been analyzed. It is demonstrated that such films can be characterized by TOFSIMS. In several cases surface analyses by XPS and AES were also carried out in order to illustrate the complementary information that can be obtained by the application of these three major surface analysis techniques. The analysis of the paint-metal interfaces by TOFSIMS allows conclusions to be drawn about the state of cure of the paint and about preferential segregation of low-molecular-weight paint constituents to the metal surface.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Thin (750 Å) plasma-polymerized films of acetylene were deposited onto polished steel substrates in an inductively coupled r.f. reactor. The films were characterized by x-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), Auger electron spectroscopy (AES) and secondary ion mass spectrometry (SIMS) immediately after deposition and after aging in the atmosphere. The FTIR spectra of the as-deposited films were characterized by bands related to mono- and disubstituted acetylene groups and by bands related to methyl and methylene groups. During exposure to the atmosphere, bands related to acetylenic groups decreased in intensity while new bands due to carbonyl groups appeared. When XPS spectra were obtained from films that were exposed to the atmosphere, new components assigned to oxidation products were observed in the C 1s spectra that were not observed for as-deposited films, verifying that oxidation had occurred. Numerous peaks related to aromatic structures were observed in positive SIMS spectra of as-deposited films. Results obtained from AES showed that the plasma-polymerized films were continuous and that the oxide on the substrate surface was partially reduced during deposition.Plasma-polymerized acetylene films were excellent primers for rubber-to-steel bonding. Miniature lap joints were prepared by using rubber as an ‘adhesive’ to bond together pairs of polished steel adherends primed with plasma-polymerized acetylene films. The force required to break the as-prepared joints was ∼2000 N for a bonded area of 64 mm2 and failure was 100% cohesive in the rubber. Similar results were obtained for joints prepared using polished brass substrates.Because of the complexity of reactions between rubber and the plasma-polymerized primer, a model ‘rubber’ consisting of a mixture of squalene, zinc oxide, carbon black, sulfur, stearic acid, cobalt naphthenate, N,N-dicyclohexylbenzothiazole sulfenamide and diaryl-p-diphenyleneamine was used to simulate the cross-linking reaction. The results obtained using XPS, SIMS, AES and FTIR showed that sulfur diffused through the primer to form a layer of sulfide at the primer/substrate interface. Zinc and cobalt sulfides and perthiomercaptides, which formed at the interface between squalene and the plasma-polymerized acetylene primer, catalyzed the reaction between squalene and the primer. Cross-links between squalene and the primer were mostly mono-sulfidic, although some evidence for di- and trisulfidic cross-links was observed.
    Additional Material: 17 Ill.
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  • 5
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Thin films of plasma-polymerized hexamethyldisiloxane (PP-HMDS) were deposited on stainless-steel substrates from a parallel-plate DC reactor. The parameters were varied between 6.7 and 66.7 Pa for the monomer pressure and 0.4 and 20 W for the discharge power. The deposition times ranged from 5 to 600 s, thus enabling an analysis of both the film/metal interface region and the bulk of the films. Characterization of the deposits was performed using XPS, reflection-absorption Fourier transform infrared spectroscopy, time-of-flight SIMS and scanning tunneling microscopy (STM). The results strongly suggest that the structure of the plasma polymer close to the interface is different from that of the bulk. In the case of low power and high pressure (LW/HP) deposition conditions, a non-crosslinked film is formed initially which appears to be covalently bonded to the substrate via Me-C bonds (Me=Fe and/or Cr). Film growth starts at nucleation sites on the steel surface. After approximately 1 min of deposition, the film structure gradually changes and becomes more crosslinked. In high power/low pressure (HW/LP) conditions, the surface coverage of the steel is initially higher and the film has a considerably higher degree of crosslinking, which does not change much during film growth. Time-of-flight SIMS analysis of the thick films confirmed the difference between the degree of crosslinking of the films deposited under different conditions. Remarkably, the elemental composition of the thick films formed at HW/LP and LW/HP conditions was approximately the same, as was concluded from XPS analyses. The STM images of the various films corroborated the initially more homogeneous coverage by the HW/LP film as compared with the LW/HP film. The images of the thick films suggested a strong effect of the concurrent ion bombardment in the case of the HW/LP film. A model for the mechanism of film growth and the effect of deposition conditions is proposed.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Positive static SIMS spectra of poly(methylmethacrylate) (PMMA) and perdeuterated PMMA have been compared. The usefulness of this approach for the distinction between hydrocarbon and oxygen-containing secondary ions is demonstrated. For example, a major characteristic fragment like the one at 69 amu, which had been tentatively identified as C5H9+ by other authors, was shown to be C4H5O+.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 11 (1988), S. 539-541 
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Static SIMS has been used to analyze the sulfur cross-links at the surface of compounded polyisoprene rubbers. Linear relationships were found between the normalized intensities of S1- ions and the total cross-link densities and between the intensities of the S4- clusters and the percentages of the polysulfidic cross-links.
    Additional Material: 2 Tab.
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  • 9
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Plasma-polymerized coatings on metal substrates have been suggested as corrosion protection layers, but not much is known about the properties of these films and how these properties relate to the corrosion performance of coated metals. In this study, trimethylsilane plasma films were deposited on cold-rolled steel (CRS) under different deposition conditions. Angular-dependent XPS, AES and time-of-flight (TOF)-SIMS were used to characterize the films. These three techniques were highly complementary in nature. All films were silicon-based and the hydrocarbon content was a function of the deposition conditions. The AES depth profiles indicated that pretreatment of the substrate with oxygen had a significant effect on the type of film produced. Both TOF-SIMS and XPS revealed that the surface of the film was different from the bulk. The surface was oxygen-rich and was apparently modified upon exposure of the plasma film to the atmosphere. Both silicon and carbon were highly oxidized in the surface layers. Thus, these plasma films consist of at least three distinctly different regions: an interfacial region where the film is intimately mixed with the metal oxide; a bulk region with approximately the same elemental composition as the monomer; and a highly oxidized surface region. A correlation between the type of plasma film produced and the deposition conditions is discussed briefly.
    Additional Material: 10 Ill.
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  • 10
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The improvement in spatial resolution of scanning Auger spectroscopy in recent years has increased its applicability to industrial problems markedly, as is illustrated by several case studies in adhesion, corrosion and related areas. It is shown that the analytical capabilities of AES are enhanced if complemented by simultaneous energy-dispersive x-ray analysis. Suggestions for further development of AES instruments for use in industrial R&D are given.
    Additional Material: 32 Ill.
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