Bronson D. Hausmann, Thomas W. Hawkins, John Ballato, Minoru Tomozawa
{"title":"Effect of draw temperature and flame polishing on birefringence of silica glass fiber","authors":"Bronson D. Hausmann, Thomas W. Hawkins, John Ballato, Minoru Tomozawa","doi":"10.1111/ijag.16623","DOIUrl":"10.1111/ijag.16623","url":null,"abstract":"<p>Recently developed methods for high resolution birefringence measurement have been applied to distinguish between the surface and interior birefringence of silica glass fibers as a function of drawing temperature and initial surface condition for two types of silica glass with different water contents. Fibers were drawn in a water-free argon environment using graphite heating elements. It was found that fibers drawn at lower temperatures resulted in greater, interior birefringence, in agreement with previous reports. Additionally, it was found that in the case of low-water silica glass, flame polishing via oxygen–hydrogen mixture and drawn into fibers at lower temperature resulted in significant surface compressive stress upon drawing. This compressive stress may be the result of surface stress relaxation in silica glass that occurs in the presence of water during fiber drawing. In silica glass that contains greater internal hydroxyl impurity concentrations, the interior birefringence as well as the surface stress relaxation was significantly reduced under the same fiber drawing conditions. Characterization of such stress responses provides insight into the effects of common processing techniques as well as impresses the significance of preform processing for consistent fiber production.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"14 3","pages":"373-379"},"PeriodicalIF":2.1,"publicationDate":"2023-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45387971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Case II diffusion of water in Na2O–3SiO2 glass: Constant tensile stress gradient at the diffusion interface","authors":"Bronson D. Hausmann, Minoru Tomozawa","doi":"10.1111/ijag.16622","DOIUrl":"10.1111/ijag.16622","url":null,"abstract":"<p>Some polymers and oxide glasses exhibit unusual diffusion of liquid or gas, with the depth of diffusion exhibiting a linear increase with time, instead of normal square root of time dependence. There have been many models, but very few experimental data that can help clarify the cause of the phenomenon's existence in glass. Residual stress in sodium trisilicate glass (Na<sub>2</sub>O–3SiO<sub>2</sub>) samples was characterized following Case II water diffusion at 80°C in a saturated water vapor environment. The surface-swelled layer of the glass was removed by dissolving it in water, and birefringence of the newly revealed surface layer was measured. The presence of a constant negative tensile stress gradient was revealed by indicating that Case II diffusion in sodium trisilicate glass originates from this stress gradient, which overwhelms the more typical Fick's law concentration-dependent flux.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"14 2","pages":"330-337"},"PeriodicalIF":2.1,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49602305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hosam Othman, Brian Topper, Hagar Elkholy, Doris Möncke
{"title":"Structural, spectroscopic, and radiation shielding properties of Pb2+-doped borate and phosphate glasses","authors":"Hosam Othman, Brian Topper, Hagar Elkholy, Doris Möncke","doi":"10.1111/ijag.16621","DOIUrl":"10.1111/ijag.16621","url":null,"abstract":"<p>Lead-containing alkali/alkaline-earth borate and barium lead phosphate glasses were prepared by melt-quenching for a detailed investigation of the Pb<sup>2+</sup> ions’ optical properties. UV–Vis absorption and photoluminescence spectroscopy reveal variations in the s–p transition of Pb<sup>2+</sup>, which are shown to correlate with the optical basicity of the host glass in both borates and phosphates. Pb<sup>2+</sup> emission differs significantly for borate and phosphate glasses, as the nature of the charged sites available to accommodate Pb<sup>2+</sup> cations vary. Optical basicity values were determined from the composition (<i>Λ<sub>th</sub></i>) and the measured refractive index (<i>Λ<sub>n</sub></i>). The UV-cutoff shifts toward higher wavelengths with increasing optical basicity and lead content. In borate glasses, the frequency of the stretching modes due to nonbridging oxygen atoms of trigonal metaborate species is identified to be inversely proportional to the excitation wavelength (directly proportional to the excitation energy) of Pb<sup>2+</sup>. Lead-containing alkali and alkaline-earth borate glasses show additional correlations between the Pb<sup>2+</sup> emission wavelength and the weighted average of the field strength of the modifier(s). Complementary to the investigation of optical properties, radiation and neutron shielding parameters were calculated, suggesting the potential utility of some of the studied compositions for radiation shielding applications.</p>","PeriodicalId":13850,"journal":{"name":"International Journal of Applied Glass Science","volume":"14 3","pages":"408-424"},"PeriodicalIF":2.1,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42226571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}