Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Oxidation of copper and mobility of copper ions during anodizing of an Al - 1.5 wt.% Cu alloy (1995)
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 23 (1995), S. 892-898 
    Details
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The mechanism of oxidation of copper at the alloy/film interface, and the subsequent migration of copper ions in barrier-type films, has been examined for anodizing of an Al - 1.5 wt.% Cu alloy with a prior chemical polishing treatment. Both chemical polishing and anodizing result in formation of a thin layer of alloy at the alloy/film interface, of ∼2 nm thick, that is highly enriched in copper. The layer is present immediately beneath the different types of film formed by chemical polishing and subsequent anodizing, and contains in both cases ∼6 × 1019 Cu atoms m-2. The amount of copper contained within the enriched layer of alloy is not significantly dependent upon the anodizing voltage. During anodic film growth, both aluminium and copper ions are incorporated into the film at the alloy/film interface, on average in their alloy proportions. However, the film is depleted in copper relative to the alloy because copper ions in the film migrate faster than Al3+ ions and, on reaching the film/electrolyte interface, are ejected directly to solution. The mechanism of oxidation of copper is proposed to depend upon the formation, through prior oxidation of aluminium, of copper-rich clusters in the enriched layer of alloy at the alloy/film interface. Individual clusters are oxidized only on achieving a critical size. Consequently, copper is incorporated into the film discontinuously both in time and in position along the alloy/film interface. The films contain a high population density of flaws, which affects the film composition, the uniformity of ionic current, the faradaic efficiency of film growth, and the detailed distributions of copper ions within the films. However, the general features of film growth are compatible with the usual growth mechanism of anodic alumina, with transport numbers of Al3+ and O2-/OH- ions of ∼0.4 and ∼0.6, respectively.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/sia.740231307
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Barrier-Type anodic films on aluminium in aqueous borate solutions: 1 - Film density and stopping power of anodic alumina films for alpha particles (1983)
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 5 (1983), S. 247-251 
    Details
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Stopping powers of an anodic film, formed on aluminium in aqueous ammonium pentaborate solution, have been measured experimentally for α particles, over the energy range 0.7-2.3 MeV. Comparison between the measured stopping powers and theoretically calculated values shows that Bragg's Rule may be applied, with reasonable accuracy (∼5%), to predict the stopping powers of anodic alumina. The density of the barrier-type film was determined by Rutherford backscattering spectroscopy to be 3.10±0.15 × 103 kg m-3.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/sia.740050605
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Barrier-type anodic films on aluminium in aqueous borate solutions: 2 - Film compositions by Rutherford backscattering spectroscopy and nuclear reaction methods (1983)
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 5 (1983), S. 252-263 
    Details
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Compositions and elemental distributions of anodic films formed on aluminium in aqueous borate electrolytes have been investigated by Rutherford backscattering spectroscopy (RBS) and associated nuclear reaction methods, together with controlled crystallization of film sections in the transmission electron microscope (TEM). Films were found to consist principally of Al2O3; the outer regions of the films were contaminated with boron and, for all cases studied, the inner regions were boron-free. In the absence of film dissolution the contaminated region represented approximately 40% of the film thickness, and this proportion did not vary significantly with changes in current density of film formation. The outer region contained about 1.5 wt% boron, probably as B2O3, and the densities of the inner and outer regions were similar to an accuracy of about 10%.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/sia.740050606
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Surface kinetic aspects of Si incorporation in molecular beam epitaxial growth of GaAs (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 14 (1989), S. 619-622 
    Details
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The incorporation and amphoteric behavior of Si impurities in Si-doped (100) oriented molecular beam epitaxial (MBE) GaAs layers grown under different As4/Ga flux ratios but with a fixed Si flux have been studied using Hall effect measurements, photothermal ionization spectroscopy and photoluminescence. The Si donor concentration increases substantially with increasing As4/Ga flux ratio, while the Si acceptor concentration remains less than ∼ 1013 cm-3, regardless of the variation of As4/Ga flux ratio. The observed increase of carrier concentration with increasing V/III ratio is not due to a change of site preference of Si impurities from Ga to As sublattice sites as previously supposed, but is due to the increase in incorporation of Si donor. This result can be explained by the kinetic effects associated with surface reaction processes involved in Si impurity incorporation. From these results it is clear that the sticking coefficient of Si is less than unity, and varies with the growth conditions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/sia.740141010
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A new carbon fiber from lignin (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 44 (1992), S. 127-134 
    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: A new carbon fiber was prepared from the lignin (steam-exploded lignin), which was isolated from steam-exploded birch wood (Betula platyphylla). The lignin was modified to melt thermally on hydrogenolysis. The chloroform soluble and carbon disulfide insoluble fraction (HL) of the reaction products was heated at 300-350°C for 30 min, giving a molten viscous material (HHL). The HHL had a softening point of 110°C and melted at over 145°C to form viscous liquid. When HHL was subjected to a spinning test, according to a conventional fusion spinning method at a speed over 100 m/min, a fine filament could be continuously formed through a pinhole (diameter: 0.3 mm). After the filaments were heated in air at 1-2°C/min up to 210°C, by which time the filament was converted to have an infusible property, the filaments were carbonized by heating from a room temperature to 1000°C at a heating rate of 5°C/min in a stream of nitrogen. The typical properties of the lignin based carbon fiber were as follows: Fiber diameter = 7.6 ± 2.7μ Elongation = 1.63 ± 0.29% Tensile strength = 660 ± 230 MPa; Modulus of elasticity = 40.7 ± 6.3 GPa. The chemical structure of the precursor was remarkably changed from that of the original lignin, indicating the elimination of aliphatic functional groups implied originally in the starting material.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1992.070440113
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Resist system based on the cationic photocrosslinking of poly(4-hydroxystyrene) and polyfunctional electrophiles (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 1-11 
    Details
    ISSN: 0887-624X
    Keywords: chemical amplification ; photoresist ; poly(p-hydroxystyrene) ; photocrosslinking ; carbocationic ; radiation-sensitive ; crosslinker ; triarylsulfonium salt ; thin-film chemistry ; UV ; E-beam ; x-ray ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New resist systems based on acid-catalyzed, electrophilic aromatic substitution are described. These new resists show high sensitivity to deep UV and E-beam radiation with values approaching 2 mJ/cm2 and 2 μC/cm2, respectively. The resists are based on a three component system consisting of poly(4-hydroxystyrene), a polyfunctional, low molecular weight, latent electrophile, and a photoactive onium salt used as an acid generator. Irradiation of the resist film produces a latent image of acid dispersed in the matrix. During the postbaking step the photo-generated acid reacts with the latent polyfunctional electrophile and releases a reactive carbocationic intermediate with concomitant liberation of acetic acid. The carbocationic intermediate then reacts with neighboring phenolic moieties in a crosslinking reaction. The substitution reaction liberates a proton, making the process catalytic in nature, thus incorporating the concept of chemical amplification. These highly sensitive materials can be used as nonswelling negative multipurpose resists that function in deep-UV, x-ray or E-beam modes. © 1993 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080310101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    A new modification method of exploded lignin for the preparation of a carbon fiber precursor (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 48 (1993), S. 1485-1491 
    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: A lignin-pitch for carbon fiber was prepared in a high yield from exploded lignin on phenolysis followed by heat treatment under a vacuum. The lignin-pitch had an excellent spinnability in the melt state to form a fine filament. The green fibers were easily made infusible when heated in air at a relatively high heating rate (15-60°C/h). The lignin-based carbon fiber was produced in 43.7% of yield based on a starting material. The tensile strength was more than 400 MPa, indicating that the lignin-based carbon fiber is classified into a general purpose grade. © 1993 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1993.070480817
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Time-dependent changes in the mechanical properties of zirconia ceramic (1993)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 27 (1993), S. 729-734 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Zirconia has received special attention, mainly because of its high strength and toughness. However, there is some controversy about the time-dependent deterioration of its mechanical properties. To examine the change in mechanical properties of zirconia ceramics in vivo and in vitro, tetragonal zirconia polycrystal pieces were introduced into the medullary cavity of the tibia in Japanese rabbits and animals were sacrificed after 2, 4 and 6 weeks and 6, 12, and 30 mo, respectively. Alumina ceramic and hydroxyapatite (HAP) pieces were used as controls to investigate the differences in biocompatibility. Zirconia showed a bending strength of over 1000 MPa initially, and little time-dependent change in strength was found in both in vivo environments. x-Ray analysis showed little change in the transformation rate, i.e., less than 5 mol % in vivo and in vitro over a period of 3 years. To estimate time-dependent changes in zirconia over a longer period, zirconia pieces were placed in 95°C saline solution for over 3 years and their mechanical properties examined at chosen intervals. No serious decrease of bending strength was found over the 3-year period under these conditions. It is concluded that zirconia can be used clinically because it retains a bending strength of over 700 MPa under any experimental conditions for over 3 years. © 1993 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820270605
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Preparation of self-supporting anodic barrier films on aluminium for backscattering analysis (1982)
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 4 (1982), S. 208-211 
    Details
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A technique for the preparation of self-supporting windows of anodic barrier films on aluminium, which are essential for the precise interpretation of Rutherford backscattering data, is described. The generation of the window comprises several steps which include: (1) electropolishing of the superpure aluminium specimen in a perchloric acid/ethanol mixture; (2) masking a region of surface of the electropolished specimen with ‘Lacomit’ paint; (3) anodizing to develop a barrier-type anodic film over the exposed aluminium surface; (4) removal of the paint to reveal the non-anodized region on one face of the aluminium specimen which is then removed by electropolishing to leave the film window. Following this procedure, self-supporting windows of anodic films, free from the aluminium substrate, having effective diameters up to about 10 mm, are produced. It is shown that the use of the self-supporting window enables the Rutherford backscattering technique to be used to its full potential for the analysis of the barrier-type anodic films, enabling Al and O profiles through the film to be resolved clearly.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/sia.740040507
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...