Modification of silicophosphate glass composition, structure, and properties via crucible material and melting conditions

Sawangboon N, Nizamutdinova A, Uesbeck T, Limbach R, Meechoowas E, Tapasa K, Moencke D, Wondraczek L, Kamitsos EI, Van Wuellen L, Brauer DS (2020)

Publication Type: Journal article

Publication year: 2020

Journal

International Journal of Applied Glass Science Wiley

Book Volume: 11

Pages Range: 46-57

Journal Issue: 1

DOI: 10.1111/ijag.13958

Abstract

Ceramic crucibles are known to corrode in contact with glass melts. Here, we investigate the effect of alumina and fused silica crucibles on the composition, structure, and properties of silicophosphate glasses. Glasses in the system 0.3 Na2O-0.6 P2O5-0.1 SiO2 were melted in platinum, alumina, or fused silica crucibles at 900°C or 1200°C for 0.5-12 hours. Al2O3 and SiO2 were found to leach from the crucibles into the glass melt and alter the glass composition: Al2O3 content increased with melting temperature and time, resulting in up to 10 mol% Al2O3; SiO2 from fused silica crucibles was also introduced into the glass, resulting in a 25% higher SiO2 content compared to the nominal composition. Glass density, transition temperature, thermal expansion, and mechanical properties were strongly affected by these compositional changes. Based on vibrational spectroscopy, this is explained by increasing numbers of P–O–Al or P–O–Si bonds, resulting in a depolymerization of the phosphate network, and ionic cross-linking by high field strength aluminum or silicon ions. With increasing alumina content, P–O–Si bonds were replaced by P–O–Al bonds. 31P and 27Al MAS NMR spectra revealed that aluminum is present in sixfold coordination exclusively and fully bonded to phosphate species, connecting phosphate groups by P–O–Al–O–P bonds.

Authors with CRIS profile

Lothar Wondraczek

Involved external institutions

Friedrich-Schiller-Universität Jena DE Germany (DE) Universität Augsburg DE Germany (DE) National Hellenic Research Foundation (NHRF) / Εθνικό Ίδρυμα Ερευνών GR Greece (GR)

How to cite

APA:

Sawangboon, N., Nizamutdinova, A., Uesbeck, T., Limbach, R., Meechoowas, E., Tapasa, K.,... Brauer, D.S. (2020). Modification of silicophosphate glass composition, structure, and properties via crucible material and melting conditions. International Journal of Applied Glass Science, 11(1), 46-57. https://doi.org/10.1111/ijag.13958

MLA:

Sawangboon, Nuttawan, et al. "Modification of silicophosphate glass composition, structure, and properties via crucible material and melting conditions." International Journal of Applied Glass Science 11.1 (2020): 46-57.

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