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  • 1
    Electronic Resource
    Electronic Resource
    Structural investigation of silica gel films by infrared spectroscopy (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 4225-4232 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Fourier transform infrared absorption spectroscopy has been utilized to characterize the structure of porous silica gel films, both deposited on c-Si substrates and free standing. The films were either dried at room temperature or subjected to partial densification at 400–450 °C. The spectra of the gel films are compared to those of thermal SiO2 grown on c-Si and to Kramers–Kronig analysis of the reflection spectra of bulk SiO2 gels and v-SiO2. The gel films show small frequency shifts compared to the latter spectra and they also exhibit new bands due to the presence of OH groups, although very little molecular water or residual organic species were found. The results are interpreted in terms of the gel structure. Compared to the thermal oxide, the sharp peak near 1070 cm−1 is narrower for the gels and the spread in intertetrahedral angles is estimated at 24° and 27° for room temperature dried and partially densified gels, respectively, compared to 33° for the thermal oxide. This is in agreement with a state of strain in the Si—O—Si bridges of the gels near the surface of the pores. The gel films have also a stronger shoulder near 1200 cm−1, whose intensity decreases with heat treatment of the gel. Its nature is related to the longitudinal optical (LO) component of the high-frequency vibration of SiO2 and it is suggested that the gel pores may account for the activation of the LO component.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.346213
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  • 2
    Electronic Resource
    Electronic Resource
    Hydroxylation and Dehydroxylation Behavior of Silica Glass Fracture Surfaces (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The hydroxylation and dehydroxylation behavior of amorphous silica fracture surfaces was studied using temperature-programmed static SIMS. The results show that vacuum heat treatments result in more extensive condensation of silanol groups on the silica glass fracture surface as compared to fumed silica (Cabosil). This is attributed to differences in the distribution of silanol groups on the two silica surfaces. The rehydration kinetics of the dehydroxylated silica fracture surfaces showed two distinct reaction rates—an initial rapid increase in the silanol concentration, followed by a slower rehydration for longer dosing times. The slower rehydration reaction was shown to follow first-order reaction kinetics with the reaction rate constant, suggesting hydrolysis of strained siloxane bonds on three-membered silicate ring structures. The much faster initial rehydration is attributed to the hydrolysis of extremely strained siloxane bonds in two-membered, edge-shared tetrahedral rings. The effect of the dehydration time and temperature (i.e., thermal history of the surface) on the rehydration kinetics is also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00303.x
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  • 3
    Electronic Resource
    Electronic Resource
    Effect of Enameling on the Strength and Dynamic Fatigue of Soda–Lime–Silica Float Glass (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The effect of a glass enamel coating on the strength and fatigue behavior of float glass was investigated. Commercially available enamel that was comprised of Cu2Cr2O4 pigment particles in a bismuth-zinc borosilicate glass matrix was applied to a soda–lime–silica float glass via screen printing, followed by fusion at elevated temperature. Strengths of the enameled specimens were evaluated in biaxial flexure using a ring-on-ring (ROR) test geometry, and the data were analyzed using a conventional two-parameter Weibull distribution. Enameling was found to significantly degrade the strength of the float glass. There was no statistical difference in the characteristic strengths of samples enameled on the air side (66 MPa) compared with samples enameled on the tin side (61 MPa) of the float glass. Fractographic analysis revealed that the failures in the enameled float glass samples initiated at pores and pigment aggregates in the enamel, whereas failures in float glass samples initiated solely from surface flaws. Dynamic fatigue tests were performed on enameled float glass and indented float glass samples to determine the effect of the enamel on the stress corrosion behavior of the enameled components. There was no statistically significant difference between the stress corrosion exponents for the float glass and enameled float glass specimens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00488.x
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  • 4
    Electronic Resource
    Electronic Resource
    An organometallic route to micron-sized whiskers of zinc sulfide (1988)
    s.l. : American Chemical Society
    Inorganic chemistry 27 (1988), S. 3267-3269 
    Details
    ISSN: 1520-510X
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ic00292a002
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  • 5
    Electronic Resource
    Electronic Resource
    Solution/gelation of arsenic trisulfide in amine solvents (1989)
    s.l. : American Chemical Society
    Chemistry of materials 1 (1989), S. 558-563 
    Details
    ISSN: 1520-5002
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/cm00005a018
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  • 6
    Electronic Resource
    Electronic Resource
    Biaxial Flexure Strength and Dynamic Fatigue of Soda–Lime–Silica Float Glass (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The strength and dynamic fatigue behavior of float glass was investigated using biaxial flexure tests. The samples were tested using the ring-on-ring (ROR) biaxial flexure test geometry, and the data analyzed using a conventional two-parameter Weibull distribution. The as-received samples revealed that the air side exhibits a higher characteristic strength (243 MPa) compared with the tin side (114 MPa); fractographic analysis confirmed the presence of significantly larger flaws on the tin side of the specimens, presumably due to contact damage by the rollers in the float glass process. Dynamic fatigue results for as-received and indented samples were performed to assess whether differences in the stress corrosion behavior of float glass exist because of tin penetration. No statistical difference in the stress corrosion exponent was found between the air (n= 21.7) and tin (n= 21.6) sides of the float glass. This indicates either that the tin penetration (which extends ∼25 μm) plays no role in altering the stress corrosion susceptibility of float glasses because the native flaw size is larger than the tin penetration depth or that the tests do not have the required sensitivity to distinguish the effect of the tin. Alternative test methods for direct observation of slow crack growth in tin-doped bulk glasses are planned to investigate this in the future.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00352.x
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  • 7
    Electronic Resource
    Electronic Resource
    Mechanisms for Silanol Formation on Amorphous Silica Fracture Surfaces (1999)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 82 (1999), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Amorphous SiO2fracture surfaces created under different partial pressures of water vapor (pH2O) were analyzed using temperature-programmed static secondary ion mass spectroscopy. The results were used to develop an atomistic model for the formation of a fracture surface. It was found that substantial reconstruction of the SiO2fracture surface took place immediately after the fracture event. Formation of the fracture surface was modeled as three individual steps-rupture of Si-O-Si bonds to form dangling Si* and Si-O* bonds, reconstruction and relaxation of the surface to form both strained and unstrained siloxane bonds, and, lastly, reaction of H2O molecules with strained siloxane bonds to form surface silanol groups. The final concentration of surface silanol groups was found to have only a weak dependence on the pH2O in the ambient atmosphere during the fracture process. It was also found that the number of strained siloxane bonds on the SiO2fracture surface could be substantially reduced by heat treatment of the glass under vacuum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1999.tb01909.x
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  • 8
    Electronic Resource
    Electronic Resource
    Synthesis of Silicon Carbide Thin Films with Polycarbosilane (PCS) (1997)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 80 (1997), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Polycarbosilane (PCS) thin films were deposited on silicon (and other) substrates and heat treated under vacuum (∼10--6〉torr)at temperatures in the range of 200°–1200°C. At temperatures in the range of 1000°–1200°C, the initially amorphous PCS films transformed to polycrystalline ß-silicon carbide (ß-SiC). Although PCS films could be deposited at thickness up to 2 μm, the films with thicknesses 〉1 μm could not be transformed to SiC without extensive cracking. The resulting SiC coatings were characterized using Fourier transform infrared spectroscopy, glancing-angle X-ray diffractometry, secondary-ion mass spectroscopy, Raman spectoscopy, transmission electron microscopy, and scanning electron microscopy. The temperature and time dependence of the amorphous-to-crystalline transition could be associated with the evolution of free carbon, oxygen, and hydrogen in the films.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1997.tb03124.x
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  • 9
    Electronic Resource
    Electronic Resource
    Processing Effects on the Surface Composition of Glass Fiber (2000)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 83 (2000), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: In this study, differences in the surface composition of commercial glass fiber have been characterized as a function of process. The two processes studied were flame attenuation, a high-temperature combustion-assisted process, and continuous filament drawing through a bushing. The techniques used to determine the surface compositions were TOF-SIMS and XPS; the presence of a very thin, boron-depleted silica-enriched layer on the flame-attenuated fibers was most significant. Thermodynamic modeling of the equilibrium vapor pressures at the surface, during fiberization, showed significant differences in the behavior of Na, B, and F species in the two processes. To further test the models, glass fibers were produced under more closely controlled conditions in a laboratory-scale flame attenuation system. These experiments verified the important effect of flame temperature and residence time in creating the surface layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2000.tb01571.x
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  • 10
    Electronic Resource
    Electronic Resource
    Effects of Tin on the Physical Properties and Crack Growth in Soda-Lime-Silica Float Glass (2004)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 264-268 (May 2004), p. 1859-1862 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/48/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.264-268.1859.pdf
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